00756nas a2200205 4500008004100000245013700041210006900178300001100247490000800258100002200266700002100288700001600309700002400325700002300349700002100372700002300393700002300416700002100439856009000460 2022 eng d00aPredation, parasitism, and drought counteract the benefits of patch-burn grazing for the reproductive success of grassland songbirds0 aPredation parasitism and drought counteract the benefits of patc a1–220 v1241 aVerheijen, B.H.F.1 aErickson, Amy, N1 aBoyle, W.A.1 aLeveritte, Kiana, S1 aSojka, Jennifer, L1 aSpahr, Lauren, A1 aWilliams, Emily, J1 aWinnicki, Sarah, K1 aSandercock, B.K. uhttps://academic.oup.com/condor/advance-article/doi/10.1093/ornithapp/duab066/650648200436nas a2200133 4500008004100000022001300041245007100054210006900125300001100194490000800205100002100213700001700234856005100251 2020 eng d a2058841000aLongevity records show that Upland Sandpipers are long-lived birds0 aLongevity records show that Upland Sandpipers are longlived bird a60 -640 v1271 aSandercock, B.K.1 aKramos, Greg uhttps://www.waderstudygroup.org/article/13459/02824nas a2200253 4500008004100000245008800041210006900129260001600198300000600214490000700220520209500227653002202322653001402344653001302358653002002371653002202391653001902413100002202432700001602454700001802470700001702488700002102505856004402526 2019 eng d00aEffects of patch-burn grazing on breeding density and territory size of Dickcissels0 aEffects of patchburn grazing on breeding density and territory s cJan-01-2019 a70 v143 a

Ongoing habitat loss and intensification of management of remaining grasslands have led to large population declines of grassland songbirds in North America. As an alternative to intensive and homogeneous use of rangelands, patch-burn grazing creates heterogeneity in vegetative structure across the landscape by restoring the historical interaction of fire and grazing by large ungulates. Patch-burn grazing can increase diversity and abundance of grassland songbirds, but effects on local breeding density and territory size remain unknown, despite both being important in regulating population dynamics of species. Understanding patterns of density and territory size across the landscape is especially important for species experiencing steep declines in breeding habitat, such as grassland songbirds. During a two-year field study, we tested how densities and territory sizes of Dickcissels (Spiza americana), a common grassland songbird, varied among treatment units that were managed with patch-burn grazing or annual burning with or without grazing at a tallgrass prairie site in northeastern Kansas. We found that local densities of male Dickcissels did not differ among management regimes. However, within the patch-burn grazing treatment, densities were highest in the patch that was burned the previous year and lowest in the most recently burned patch. Furthermore, densities of male Dickcissels were lower in 2013 than in 2014, especially in burned and grazed units that had little vegetative structure and nest cover after the drought conditions of the previous two years. Territory size was not affected by rangeland management, while local densities of Dickcissels only explained ~10% of the variation in territory size. Our results show that patch-burn grazing does not negatively impact densities of breeding Dickcissels compared to annual burning and grazing. Moreover, Dickcissel populations might benefit from patch-burn grazing if males preferentially settle in unburned patches with high forb cover, especially during or directly following drought conditions.

10adistance sampling10agrassland10asongbird10aSpiza americana10atallgrass prairie10aterritoriality1 aVerheijen, B.H.F.1 aClipp, H.L.1 aBartolo, A.J.1 aJensen, W.E.1 aSandercock, B.K. uhttp://www.ace-eco.org/vol14/iss1/art7/02813nas a2200169 4500008004100000245008000041210006900121300001300190490000700203520228200210100002302492700001602515700002102531700002002552700001302572856005802585 2019 eng d00aHabitat selection and space use of Upland Sandpipers at nonbreeding grounds0 aHabitat selection and space use of Upland Sandpipers at nonbreed a14:art180 v143 a

Habitat requirements of migratory birds can be dynamic during the annual cycle, and understanding habitat use during the nonbreeding season is important for conservation planning. In grassland birds, habitat selection is often determined by features of vegetative structure that are associated with predation risk, food resources, or thermal environments. And, these habitats are affected by anthropogenic influences such as agriculture conversion and production of livestock. In our four-year field study, we examined the space use and habitat selection of Upland Sandpipers (Bartramia longicauda) during the nonbreeding season in an area of private grasslands managed for livestock production within the Northern Campos ecoregion of Uruguay. We radio-tracked sandpipers during the nonbreeding season to test the hypothesis that space use, habitat selection, and flock size were determined by vegetative structure in managed grasslands with different grazing and agricultural management regimes. We captured and tagged 62 sandpipers during the nonbreeding season in the austral summer, and recorded a total of 506 locations for our sample of radio-marked birds. Foraging Upland Sandpipers primarily selected two types of native grasslands associated with shallow, rocky soils. The vegetation configuration of disturbed pastures were open landscapes that were good for detection of arthropod prey but offered little cover for avoidance of predators. Sandpipers were usually found in small groups of 2–20 birds, and the largest flocks of 40–50 birds were found in pastures with relatively short grass cover (20 to 40% tall grass cover). Low to moderate stocking densities of domestic livestock created variation in vegetation height and cover in large areas and allowed for coexistence of grassland birds with different habitat requirements. Upland Sandpipers preferred disturbed areas, which may not support the needs of other species of grasslands birds. Our results emphasize the need for habitat heterogeneity and disturbance forces such as grazing in grassland systems. Our research contributes new information on the ecology of migratory grassland birds and provides insights for biodiversity conservation on private lands used for livestock production.

1 aAlfaro-Barrios, M.1 aLiguori, L.1 aSandercock, B.K.1 aBerazategui, M.1 aArim, M. uhttps://brage.nina.no/nina-xmlui/handle/11250/263276303015nas a2200229 4500008004100000245007000041210006900111300000800180490000600188520230300194653002502497653002502522653002202547653002802569653001302597653001402610653002402624100002002648700002102668700002602689856007002715 2019 eng d00aMigration patterns of upland sandpipers in the western hemisphere0 aMigration patterns of upland sandpipers in the western hemispher a4260 v73 a

Integrated models of the ecology of migratory species require tracking of individual migratory organisms throughout the annual cycle. Here, we report the first information on the movement patterns of nine Upland Sandpipers (Bartramia longicauda) that were captured at breeding sites in Kansas and Massachusetts, and tracked with GPS and PTT tags to non-breeding sites in South America. Upland Sandpipers were extreme migrants that regularly made non-stop flights that were >5,000 km in length and lasted up to 7 days. Sandpipers traveled up to 20,000 km per year in their annual movements. Our project resulted in a series of new discoveries. Sandpipers regularly crossed major ecological barriers during migration, which included long oceanic flights, high elevation mountains, and tropical forests. Migrating birds used known stopover sites in the central flyway of North America and eastern slope of the Andes in South America, and a subset of birds wintered in core non-breeding sites in the Pampas ecoregion of Uruguay and Argentina. We documented new staging sites at canefields in the mountain valleys of Colombia, grasslands in the Llanos of Venezuela, and at airports along the Atlantic Coast of the US. Unexpectedly, some sandpipers spent the non-breeding season on river islands in the Amazon basin, and pastures in the Cerrado ecoregion of Brazil; areas not previously known to host overwintering Upland Sandpipers. Like many other migratory birds in the Western Hemisphere, Upland Sandpipers had elliptical migration routes within the Southern Hemisphere, moved among separate activity areas during the non-breeding season, migrated faster during northbound than southbound migration, and spent more time at non-breeding than breeding sites. Collectively, the birds used sites across much of northern South America as a broad front migrant. Overall, the migratory patterns of Upland Sandpipers were more similar to migratory landbirds than to shorebirds that typically stage at wetlands and coastal estuaries. Upland Sandpipers should be buffered against habitat loss and degradation at local sites within their migratory range, but it may be difficult to protect specific sites or broad landscapes that would be needed to conserve a high percentage of the global population.

10aBartramia longicauda10aelliptical migration10afull annual cycle10along-distance migration10aseasonal10aSpace use10atransoceanic flight1 aHill, Jason, M.1 aSandercock, B.K.1 aRenfrew, Rosalind, B. uhttps://www.frontiersin.org/articles/10.3389/fevo.2019.00426/full02219nas a2200157 4500008004100000245009200041210006900133300001400202490000700216520169300223100002301916700002101939700002101960700001701981856006301998 2018 eng d00aBody condition and feather molt of a migratory shorebird during the non-breeding season0 aBody condition and feather molt of a migratory shorebird during  ajav-014800 v493 a

Migratory shorebirds have some of the highest fat loads among birds, especially species which migrate long distances. The Upland Sandpiper (Bartramia longicauda) makes long-distance migrations twice a year, but variation in body condition or timing of feather molt during the non-breeding season has not been studied. Molt is an important part of the annual cycle of migratory birds because feather condition determines flight performance during migration, and long-distance movements are energy costly. Howerver, variation in body condition during molt has been poorly studied. The objective of our field study was to examine the timing and patterns of feaher molt of a longo distance migratory shorebird during the non-breeding season and test for relationships with body size, fat depots, mass, and sex. Field work was conducted at four ranches in the Northern Campos of Uruguay (Paysandú and Salto Departments). We captured and marked 62 sandpipers in a 2-month period (Nov-Jan) during four non-breeding season (2008-2012). Sex was determinded by genetic analyses of blood samples taken at capture. Molt was measured in captured birds using rank scores based on published standards. Body mass and tarsus length measurements showed female-biased sexual size dimorphism with males smaller than females. Size-corrected body mass (body condition) showed a U-shaped relationship with the day of the season, indicating that birds arrived to non-breeding grounds in relatively good condition. Arriving in good body condition at non-breeding grounds is probably important because of the energetic demands due to physiological adjustments after migration and the costs of feather molt.

1 aAlfaro-Barrios, M.1 aSandercock, B.K.1 aLiguori, Luciano1 aArim, Matias uhttps://onlinelibrary.wiley.com/doi/full/10.1111/jav.0148002944nas a2200133 4500008004100000245008500041210006900126520245400195100002502649700002102674700002202695700002102717856007202738 2017 eng d00aEffects of rangeland management on survival of female greater prairie‐chickens0 aEffects of rangeland management on survival of female greater pr3 a

Identifying relationships between habitat selection and population processes is important for habitat management and wildlife conservation. For prairie-obligate species, space use and demography in extant grasslands are influenced by habitat conditions caused by rangeland management practices associated with livestock production. Greater prairie-chickens (Tympanuchus cupido) are an indicator species for native tallgrass prairie ecosystems, but populations have declined in the Flint Hills ecoregion of eastern Kansas, USA because of intensification of rangeland management practices, including annual prescribed fire and high stocking densities. Patch-burn grazing is a rotational system that provides heterogeneous habitats and can improve productivity of grassland birds, but the effects of grazing systems on habitat use or survival of greater prairie-chickens are unknown. We used 3 types of survival analyses to investigate impacts of rangeland management on female greater prairie-chickens in the central Flint Hills during 2011–2013: Kaplan–Meier models and Cox proportional hazards to examine factors affecting annual survival rates, hazard functions to assess seasonal patterns of mortality, and Andersen–Gill models to explore the links between habitat selection and cause-specific mortality risk. Females captured at properties managed with patch-burn grazing had annual survival rates (0.61 ± 0.07 SE) that were 35% higher than females on properties managed with annual burning and intensive early cattle stocking (0.45 ± 0.06). Moreover, females that selected habitats associated with intensive management had increased mortality risk and were particularly vulnerable to avian predators, whereas females that selected habitats created by patch-burn grazing experienced lower overall mortality risk but were more vulnerable to mammalian predators. Overall mortality risk was significantly reduced under patch-burn grazing management, and widespread implementation of annual spring burning and intensive early stocking is likely depressing survival of greater prairie-chickens in the Flint Hills ecoregion. Our results join a growing body of evidence that patch-burn grazing can provide higher quality grassland habitats for native wildlife species than current rangeland management associated with intensive cattle production. © 2017 The Wildlife Society

1 aWinder, Virginia, L.1 aMcNew, Lance, B.1 aPitman, James, C.1 aSandercock, B.K. uhttps://wildlife.onlinelibrary.wiley.com/doi/abs/10.1002/jwmg.2133102493nas a2200217 4500008004100000245008900041210006900130300001200199490000800211520184400219653003102063653001902094653001802113653001302131653002202144653001102166100002202177700001802199700002102217856003702238 2017 eng d00aHabitat guild drives variation in apparent survival of landbirds in the Great Plains0 aHabitat guild drives variation in apparent survival of landbirds a259-2700 v1293 a

Many species of songbirds in the United States have shown widespread declines in population numbers during the last five decades. To understand ongoing declines and plan for conservation, researchers need reliable estimates of adult survival and site fidelity. However, variation in adult survival and site fidelity within and among species is substantial and could have consequences for management. Estimates of adult survival are lacking for many bird species and ecoregions, including the Great Plains. In this field study, we used Cormack-Jolly-Seber mark-recapture models to analyze encounter histories of 17 species of birds captured with a 13-year systematic mist-netting effort in northeast Kansas. We estimated annual rates of apparent adult survival (/) and corrected for the probability of capture (p), and tested for effects of sex and breeding habitat guild. We present the first estimates of apparent survival for six species of songbirds, and the first estimates from the Great Plains for 13 species. Apparent survival tended to be higher for males than for females, and we found a sex effect on the probability of capture for one species. Unexpectedly, grassland- and shrubland-breeding species had higher estimates of apparent survival than forest-breeding species. Our results did not support the prevailing viewpoint that birds breeding in dynamic landscapes, such as frequently burned grasslands, should show lower apparent survival than species that breed in woody habitats. We demonstrate that habitat plays an important role in the survival and site fidelity of songbirds, and that regional differences in habitat structure could drive variation in demography. Understanding the drivers of true survival and site fidelity of songbirds will allow region-specific management for species of conservation concern.

10aCormack-Jolly-Seber models10ahabitat guilds10asite fidelity10asongbird10atallgrass prairie10awoodpe1 aVerheijen, B.H.F.1 aRintoul, D.A.1 aSandercock, B.K. uhttps://doi.org/10.1676/16-017.102758nas a2200229 4500008004100000245009400041210006900135300001400204490000700218520198900225653001502214653002902229653002302258653002002281653003402301653002302335100002502358700002102383700002002404700002102424856008302445 2017 eng d00aSpace use of female greater Prairie-Chickens in response to fire and grazing interactions0 aSpace use of female greater PrairieChickens in response to fire  a165–1740 v703 aEcological interactions between fire and grazing have shaped the evolutionary history of grassland ecosystems. Currently, grassland birds have experienced ongoing population declines, following widespread implementation of intensive rangeland management practices that reduce habitat heterogeneity. Patch-burn grazing is an alternative rangeland management strategy that promotes habitat heterogeneity and biodiversity. We conducted a 3-yr. field study in the central Flint Hills of Kansas to compare the spatial ecology of female Greater Prairie-Chickens (Tympanuchus cupido) in rangelands managed with intensive rangeland management versus patch-burn grazing. This is the first study on the effects of patch-burn grazing on the space use decisions of Greater Prairie-Chickens at the home range scale. We used seasonal estimates of home range for 6-mo breeding and nonbreeding periods, as well as resource utilization functions to investigate the response of female prairie chickens to landscape metrics describing fire, grazing, and proximity to anthropogenic structures or lek sites. In our analysis of all radio-marked females, distance to lek was consistently the strongest predictor of space use during both breeding and nonbreeding seasons. Females captured at properties managed with patch-burn grazing selected areas with low stocking rates and high fire frequencies, and they avoided recently burned areas. Our study provides new evidence that patch-burn grazing can improve grassland habitat for Greater Prairie-Chickens, an umbrella species in the tallgrass prairie ecosystem. Patch-burn grazing created preferred habitats for female Greater Prairie-Chickens, with a relatively frequent fire return interval, a mosaic of burned and unburned patches, and a reduced stocking rate in unburned areas avoided by grazers. Widespread implementation of patch-burn grazing could result in significant improvements in habitat quality for wildlife in the tallgrass prairie ecosystem.10aHome range10aintensive early stocking10apatch-burn grazing10aprescribed fire10aresource utilization function10aTympanuchus cupido1 aWinder, Virginia, L.1 aMcNew, Lance, B.1 aPitman, Jim, C.1 aSandercock, B.K. uhttps://www.sciencedirect.com/science/article/pii/S1550742416300720?via%3Dihub00489nas a2200121 4500008004100000245010000041210006900141260004300210490002100253100001900274700002100293856005300314 2016 eng d00aOf mice and coyotes: mammalian responses to rangeland management practices in tallgrass prairie0 aOf mice and coyotes mammalian responses to rangeland management  aManhattan, KSbKansas State University0 vPhD Dissertation1 aRicketts, A.M.1 aSandercock, B.K. uhttp://krex.k-state.edu/dspace/handle/2097/3273102541nas a2200133 4500008004100000245011100041210006900152300001100221490000600232520205400238100001902292700002102311856007502332 2016 eng d00aPatch-burn grazing increases habitat heterogeneity and biodiversity of small mammals in managed rangelands0 aPatchburn grazing increases habitat heterogeneity and biodiversi ae014310 v73 a

Habitat heterogeneity is a key driver of biodiversity in many ecosystems. Wildlife inhabiting the native prairies of North America evolved in a heterogeneous mosaic of habitat conditions created by fire and grazing by native ungulates. Current rangeland management practices in the tallgrass prairie ecosystem evenly distribute fire and grazing across management units and promote homogeneous habitat conditions. Patch-burn grazing is a rangeland management strategy that seeks to restore heterogeneity to rangelands via fire-grazing interactions. Our 3.5-year study tested the effects of patch-burn grazing on habitat heterogeneity and small mammal community dynamics in the Flint Hills ecoregion of eastern Kansas. To study the ecological effects of patch-burn grazing, we sampled habitat conditions and the small mammal community. We assessed habitat conditions once each growing season in a negative control that was annually burned and grazed, a positive control that was burned every four years and ungrazed, and within each of three units of a patch-burn grazing experiment (PBG) managed with rotational fire. Habitat conditions were significantly different among treatments, and a principal components analysis showed that the patch-burn grazing treatment had higher canopy cover of forbs and habitat heterogeneity than our two control units. To sample the small mammal community, we conducted monthly live trapping of small mammals on two randomly located trap grids in each of our two controls and three units of our PBG treatment. Small mammal diversity was significantly higher in the patch-burn grazing treatment and in the positive control, vs. the negative control. Moreover, a canonical correspondence analysis showed that a fire-grazing interaction was the major driver structuring small mammal communities. Patch-burn grazing is an effective strategy for restoring heterogeneity to vegetative structure and composition, and can increase biodiversity of small mammals in managed rangelands in the tallgrass prairie ecosystem.

1 aRicketts, A.M.1 aSandercock, B.K. uhttps://esajournals.onlinelibrary.wiley.com/doi/full/10.1002/ecs2.143101824nas a2200169 4500008004100000245011900041210006900160300001200229490000700241520104400248653016301292100002301455700002101478700001601499700001301515856012601528 2015 eng d00aThe diet of upland sandpipers (Bartramia longicauda) in managed farmland in their neotropical non-breeding grounds0 adiet of upland sandpipers Bartramia longicauda in managed farmla a337-3470 v263 a

The Upland Sandpiper (Bartramia longicauda) is a migratory shorebird that inhabits grasslands at the breeding and non-breeding grounds. The trophic ecology of the species is poorly known, but it is thought to be insectivorous. In this study, we describe the diet of the Upland Sandpiper and its temporal variation in grasslands of northern Uruguay. From 2008 to 2012, we collected 67 feces at nine different sites in the Departments of Salto and Paysandú. The diet consisted mainly of insects (present in 98% of the feces) belonging to three orders: Coleoptera (in 80% of feces), Orthoptera (79%), and Hymenoptera (48%). Consumption of Orthoptera and Hymenoptera varied among years. Plant remains and stones were also recorded in feces. Vegetation may have been consumed secondarily while stones could be used in food processing in the gizzard. Our study demonstrates that Upland Sandpipers are diet generalists and probably forage opportunistically, depending on resource availability and focusing on the most abundant prey items.

10aBartramia longicauda; diet; fecal analysis; food preference; grasslands; insects; Nearctic migrant; Scolopacidae; Upland Sandpiper; Uruguay; wintering grounds1 aAlfaro-Barrios, M.1 aSandercock, B.K.1 aLiguori, L.1 aArim, M. uhttp://129.130.186.12/content/diet-upland-sandpipers-bartramia-longicauda-managed-farmland-their-neotropical-non-breeding02804nas a2200325 4500008004100000245013300041210006900174300001300243490000700256520180000263653002502063653000902088653001402097653002202111653001502133653002802148653001802176653002002194653003502214653002202249100002102271700002302292700001602315700001802331700001502349700001502364700001602379700001702395856006602412 2015 eng d00aEffects of grazing and prescribed fire on resource selection and nest survival of upland sandpipers in an experimental landscape0 aEffects of grazing and prescribed fire on resource selection and a325 -3370 v303 a

Context Conservation of grassland vertebrates requires a mechanistic understanding of the effects of landscape heterogeneity on habitat selection and demographic performance. Objectives Our goal was to investigate the effects of rangeland management on resource selection and nest survival of upland sandpipers (Bartramia longicauda). Methods We conducted our project at Konza Prairie, a Long-Term Ecological Research site. The station has 60 experimental units with replicated grazing and fire treatments that create a heterogeneous landscape of different habitat patches. We radio-tracked sandpipers for two breeding seasons (2003–2004, n = 37 birds) and monitored sandpiper nests for eight seasons (2001–2008, n = 246 nests). We used resource utilization functions to examine resource selection with respect to five landscape features. Results Home ranges of sandpipers were large in contiguous prairie (x¯=8.4km2x¯=8.4km2) and explain area-sensitive occurrence in fragmented prairie. Upland sandpipers selected grazed and burned sites with short vegetation within their home range. In contrast, nest site selection was influenced by fire frequency and birds selected infrequently burned sites with greater vegetative structure. Settlement decisions affected fitness because nest survival was low in burned and grazed sites (0.068), but higher in unburned and ungrazed sites (0.201–0.247). Conclusions Our results raise concerns for conservation because private rangelands managed for livestock production are often homogeneous landscapes with heavy grazing and frequent fires. Rotational grazing and fire could be used to restore heterogeneity to grasslands but the duration of rotation, patch size, and optimal configuration require further investigation.

10aBartramia longicauda10afire10agrassland10aHabitat selection10aHome range10aLandscape heterogeneity10aNest survival10aRadio-telemetry10aResource utilization functions10atallgrass prairie1 aSandercock, B.K.1 aAlfaro-Barrios, M.1 aCasey, A.E.1 aJohnson, T.N.1 aMong, T.W.1 aOdom, K.J.1 aStrum, K.M.1 aWinder, V.L. uhttps://link.springer.com/article/10.1007%2Fs10980-014-0133-903188nas a2200301 4500008004100000245007800041210006900119300001100188490000600199520232000205100001702525700001902542700001802561700001602579700002202595700001702617700001802634700001902652700001602671700001702687700001702704700001702721700001602738700001702754700001602771700002102787856007802808 2015 eng d00aFactors affecting female space use in ten populations of prairie chickens0 aFactors affecting female space use in ten populations of prairie aart1660 v63 a

Conservation of wildlife depends on an understanding of the interactions between animal movements and key landscape factors. Habitat requirements of wide-ranging species often vary spatially, but quantitative assessment of variation among replicated studies at multiple sites is rare. We investigated patterns of space use for 10 populations of two closely related species of prairie grouse: Greater Prairie-Chickens (Tympanuchus cupido) and Lesser Prairie-Chickens (T. pallidicinctus). Prairie chickens require large, intact tracts of native grasslands, and are umbrella species for conservation of prairie ecosystems in North America. We used resource utilization functions to investigate space use by female prairie chickens during the 6-month breeding season from March through August in relation to lek sites, habitat conditions, and anthropogenic development. Our analysis included data from 382 radio-marked individuals across a major portion of the extant range. Our project is a unique opportunity to study comparative space use of prairie chickens, and we employed standardized methods that facilitated direct comparisons across an ecological gradient of study sites. Median home range size of females varied ~10-fold across 10 sites (3.6–36.7 km2), and home ranges tended to be larger at sites with higher annual precipitation. Proximity to lek sites was a strong and consistent predictor of space use for female prairie chickens at all 10 sites. The relative importance of other predictors of space use varied among sites, indicating that generalized habitat management guidelines may not be appropriate for these two species. Prairie chickens actively selected for prairie habitats, even at sites where ~90% of the land cover within the study area was prairie. A majority of the females monitored in our study (>95%) had activity centers within 5 km of leks, suggesting that conservation efforts can be effectively concentrated near active lek sites. Our data on female space use suggest that lek surveys of male prairie chickens can indirectly assess habitat suitability for females during the breeding season. Lek monitoring and surveys for new leks provide information on population trends, but can also guide management actions aimed at improving nesting and brood-rearing habitats.

1 aWinder, V.L.1 aCarrlson, K.M.1 aGregory, A.J.1 aHagen, C.A.1 aHaukos, David, A.1 aKesler, D.C.1 aLarsson, L.C.1 aMatthews, T.W.1 aMcNew, L.B.1 aPatten, M.A.1 aPitman, J.C.1 aPowell, L.A.1 aSmith, J.A.1 aThompson, T.1 aWolfe, D.H.1 aSandercock, B.K. uhttps://esajournals.onlinelibrary.wiley.com/doi/full/10.1890/ES14-00536.102419nas a2200265 4500008004100000245011100041210006900152300001200221490000600233520162300239653001001862653000901872653002201881653001501903653001301918653001301931653002001944653002001964100002201984700002102006700001602027700001602043700001602059856007802075 2013 eng d00aEffects of sexual dimorphism and landscape composition on the trophic behavior of Greater Prairie-Chickens0 aEffects of sexual dimorphism and landscape composition on the tr a79986 -0 v83 a

Partitioning of ecological niche is expected in lekking species that show marked sexual size dimorphism as a consequence of sex-specific ecological constraints. However, niche partitioning is uncertain in species with moderate sexual dimorphism. In addition, the ecological niche of a species may also be affected by landscape composition; particularly, agricultural fragmentation may greatly influence the trophic behavior of herbivores. We studied trophic niche variation in Greater Prairie-Chickens (Tympanuchus cupido), a grouse species that shows moderate sex-dimorphism. Greater Prairie-Chickens are native to tallgrass prairies of North America, although populations persist in less natural mosaics of cropland and native habitats. We used stable isotope analysis of carbon and nitrogen in blood, claws and feathers to assess seasonal differences in trophic niche breadth and individual specialization between male and female Greater Prairie-Chickens, and between birds living in continuous and fragmented landscapes. We found that females showed broader niches and higher individual specialization than males, especially in winter and autumn. However, differences between females and males were smaller in spring when birds converge at leks, suggesting that females and males may exhibit similar feeding behaviors during the lekking period. In addition, we found that birds living in native prairies showed greater annual trophic variability than conspecifics in agricultural mosaic landscapes. Native habitats may provide greater dietary diversity, resulting in greater diversity of feeding strategies.

10aBlood10adiet10aEcological niches10aEcosystems10aFeathers10ahabitats10aMating behavior10aStable isotopes1 aBlanco-Fontao, B.1 aSandercock, B.K.1 aObeso, J.R.1 aMcNew, L.B.1 aQuevedo, M. uhttps://journals.plos.org/plosone/article?id=10.1371/journal.pone.007998600684nas a2200145 4500008004100000245019800041210006900239100002100308700001700329700001600346700001800362700001700380700001500397856012600412 2013 eng d00aEnvironmental impacts of wind power development on the population biology of Greater Prairie-Chickens. U.S. Department of Energy, Final Project Report for Award DOE/EE0000526 (technical report)0 aEnvironmental impacts of wind power development on the populatio1 aSandercock, B.K.1 aWisely, S.M.1 aMcNew, L.B.1 aGregory, A.J.1 aWinder, V.L.1 aHunt, L.M. uhttp://129.130.186.12/content/environmental-impacts-wind-power-development-population-biology-greater-prairie-chickens-us02441nas a2200217 4500008004100000245009600041210006900137300001300206490000700219520169200226653004501918653002801963653002201991653002402013653003802037653002302075100001602098700001802114700002102132856007002153 2013 eng d00aSpatial heterogeneity in habitat selection: nest site selection by Greater Prairie-Chickens0 aSpatial heterogeneity in habitat selection nest site selection b a791 -8010 v773 a

Ecological relationships of animals and their environments are known to vary spatially and temporally across scales. However, common approaches for evaluating resource selection by animals assume that the processes of habitat selection are stationary across space. The assumption that habitat selection is spatially homogeneous may lead to biased inference and ineffective management. We present the first application of geographically weighted logistic regression to habitat selection by a wildlife species. As a case study, we examined nest site selection by greater prairie-chickens at 3 sites with different ecological conditions in Kansas to assess whether the relative importance of habitat features varied across space. We found that 1) nest sites were associated with habitat conditions at multiple spatial scales, 2) habitat associations across spatial scales were correlated, and 3) the influence of habitat conditions on nest site selection was spatially explicit. Post hoc analyses revealed that much of the spatial variability in habitat selection processes was explained at a regional scale. Moreover, habitat features at local spatial scales were more strongly associated with nest site selection in unfragmented grasslands managed intensively for cattle production than they were in fragmented grasslands within a matrix of farmland. Female prairie-chickens exhibited spatial variability in nest site selection at multiple spatial scales, suggesting plasticity in habitat selection behavior. Our results highlight the importance of accounting for spatial heterogeneity when evaluating the ecological effects of habitat components. © 2013 The Wildlife Society.

10ageographically weighted regression (GWR)10agreater prairie-chicken10aHabitat selection10anest site selection10aresource selection function (RSF)10aTympanuchus cupido1 aMcNew, L.B.1 aGregory, A.J.1 aSandercock, B.K. uhttps://wildlife.onlinelibrary.wiley.com/doi/abs/10.1002/jwmg.49303021nas a2200253 4500008004100000245012300041210006900164300001400233490000700247520215100254653001802405653001502423653004302438653001802481653004202499653002502541653002502566653003402591100001602625700001802641700001702659700002102676856007002697 2012 eng d00aDemography of Greater Prairie-Chickens: regional variation in vital rates, sensitivity values, and population dynamics0 aDemography of Greater PrairieChickens regional variation in vita a987 -10000 v763 a

Intensification of rangeland management has coincided with population declines among obligate grassland species in the largest remaining tallgrass prairie in North America, although causes of declines remain unknown. We modeled population dynamics and conducted sensitivity analyses from demographic data collected for an obligate grassland bird that is an indicator species for tallgrass prairie, the greater prairie-chicken (Tympanuchus cupido), during a 4-year study in east-central Kansas, USA. We examined components of reproductive effort and success, juvenile survival, and annual adult female survival for 3 populations of prairie-chickens across an ecological gradient of human landscape alteration and land use. We observed regional differences in reproductive performance, survivorship, and population dynamics. All 3 populations of prairie-chickens were projected to decline steeply given observed vital rates, but rates of decline differed across a gradient of landscape alteration, with the greatest declines in fragmented landscapes. Elasticity values, variance-scaled sensitivities, and contribution values from a random-effects life-table response experiment all showed that the finite rate of population change was more sensitive to changes in adult survival than other demographic parameters in our declining populations. The rate of population change was also sensitive to nest survival at the most fragmented and least intensively grazed study site; suggesting that patterns of landscape fragmentation and land use may be affecting the relative influences of underlying vital rates on rates of population growth. Our model results indicate that 1) populations of prairie-chickens in eastern Kansas are unlikely to be viable without gains from immigration, 2) rates of population decline vary among areas under different land management practices, 3) human land-use patterns may affect the relative influences of vital rates on population trajectories, and 4) anthropogenic effects on population demography may influence the regional life-history strategies of a short-lived game bird. © 2012 The Wildlife Society.

10acontributions10aelasticity10aland use and land cover change (LULCC)10aLeslie matrix10alife-table response experiment (LTRE)10apopulation viability10aprospective analysis10avariance-scaled sensitivities1 aMcNew, L.B.1 aGregory, A.J.1 aWisely, S.M.1 aSandercock, B.K. uhttps://wildlife.onlinelibrary.wiley.com/doi/abs/10.1002/jwmg.36902844nas a2200229 4500008004100000245011900041210006900160300001100229490000700240520205900247653001702306653002802323653002802351653004402379653002102423653002302444653002302467100001602490700001702506700002102523856007002544 2012 eng d00aEffects of rangeland management on the site occupancy dynamics of prairie-chickens in a protected prairie preserve0 aEffects of rangeland management on the site occupancy dynamics o a38 -470 v763 a

We investigated the site occupancy dynamics of greater prairie-chickens at Konza Prairie Biological Station, a protected site in northeastern Kansas that is managed for ecological research. We surveyed the site during mid-Mar to mid-May, 1981–2008, and recorded detections of birds in a grid of 6.3 ha survey plots (n = 187 plots). We used multiseason occupancy models to estimate the probabilities of occupancy (ψ) and detection (p), and tested whether land cover in woody vegetation, and land use with prescribed fire or grazing management influenced the dynamic processes of site colonization and local extinction. Probability of detection per site was consistently <1 and varied among years (p = 0.12–0.82). Site occupancy of prairie-chickens declined 40% over the study period from a high of ψ = 0.19 ± 0.02 SE in 1981 to a low of 0.11 ± 0.03 in 2008, despite protection from disturbance at leks and losses to harvest. We found that different sets of environmental factors impacted the probabilities of colonization and local extinction. Probability of colonization for an unoccupied site was negatively associated with the proportion of site occupied by woodland cover (β = −1.25), and was lower for grazed sites (β = −0.62). In contrast, probability of local extinction was affected by a weak interaction between grazing and average frequency of prescribed fire (β = −1.01), but model-averaged slope coefficients were not statistically different than 0. To conserve prairie-chickens, we recommend prairies be managed with combinations of prescribed fire and grazing that maintain a heterogeneous mosaic of prairie habitats, while preventing woody encroachment. To assess biotic responses to land management practices, field sampling should be based on occupancy models or similar techniques that account for imperfect detection. © 2011 The Wildlife Society.

10acolonization10adetection probabilities10agreater prairie-chicken10aKansas;Konza Prairie Biological Station10alocal extinction10aoccupancy modeling10aTympanuchus cupido1 aMcNew, L.B.1 aPrebyl, T.J.1 aSandercock, B.K. uhttps://wildlife.onlinelibrary.wiley.com/doi/abs/10.1002/jwmg.23702351nas a2200121 4500008004100000245008700041210006900128490000600197520194300203100002002146700002102166856004202187 2011 eng d00aDemography of female Greater Prairie-Chickens in unfragmented grasslands in Kansas0 aDemography of female Greater PrairieChickens in unfragmented gra0 v63 aPopulations of Greater Prairie-Chickens (Tympanuchus cupido) have been declining because of loss and fragmentation of tallgrass prairie habitats, and management plans require contemporary demographic data. Our objectives were to determine whether maternal nutrition or predation were determinants of nesting success and female survival. We captured and radio-marked 43 females at four leks in natural, unfragmented prairie during a 4-year study. Reproductive potential was high because females laid large clutches (10.9 ± 0.3 eggs, n = 24), renested following clutch loss (22.2%, n = 27 females), and had high egg viability (88.6 ± 5.0% of eggs hatched; n = 7 nests), but reproductive traits were not correlated with female morphometrics (mass, or tarsus and keel lengths). Daily survival rate of nests was low (0.928, n = 34 nests) resulting in a predicted nest success rate of 7.4% for a 35-day exposure period. We used known fate models to estimate weekly survival from telemetry data for 40 females. Weekly survival was 0.970 and the extrapolated survival rate for the 6-month breeding season was 45.7%. Using time-since-marking Cormack-Jolly-Seber models for live encounter data to control for transience, annual apparent survival was 0.277 ± 0.081 SE for 55 marked females after initial capture, and 0.424 ± 0.139 during subsequent intervals. Survival of females was 1.6 to 2.0 times higher during the nonbreeding season than the breeding season, presumably because females are susceptible to predation during incubation and brood-rearing. Predation of nests and females may be the main demographic factors limiting population viability because predation, and not maternal nutrition, accounted for unexpectedly low nesting success and breeding season survival of Greater Prairie-Chickens in natural habitats. Future research should investigate rangeland practices that increase residual nesting cover or reduce predator impacts.1 aAugustine, J.K.1 aSandercock, B.K. uhttp://www.ace-eco.org/vol6/iss1/art202324nas a2200241 4500008004100000245009700041210006900138300001300207490000800220520159300228653002501821653001401846653002501860653002201885653001901907653002101926653001501947653002101962100001601983700002101999700001702020856004502037 2011 eng d00aGenetic parentage and local population structure in the socially monogamous Upland Sandpiper0 aGenetic parentage and local population structure in the socially a119 -1280 v1133 a

For a single lineage of birds, the diversity of mating systems and parental care among shorebirds (Charadrii) is high, which has made them an important group for investigations of the evolution of social mating systems. From 2003 to 2007, we studied a population of the Upland Sandpiper (Bartramia longicauda) at Konza Prairie Biological Station in northeastern Kansas. Our objectives were to determine the genetic mating system of this socially monogamous shorebird and to determine whether spatial patterns of philopatry and nest placement might affect opportunities for extra-pair mating. We used six microsatellite markers to estimate rates of extra-pair paternity in 58 family groups (107 parents, 184 offspring). We found that 30% of broods contained extra-pair offspring, representing 15% of chicks, the highest rate of extra-pair paternity ever reported in a socially monogamous shorebird. High rates of extra-pair paternity were not due to the degree of relatedness between partners in mated pairs, and they did not result in greater diversity among broods with extra-pair young. We used a spatial genetic-autocorrelation analysis and found evidence for relatedness among females nesting <1 km apart. The Upland Sandpiper might have a high rate of extra-pair paternity because related females nest synchronously and in close proximity, but the probability of extra-pair young was not related to nest density or distance to nearest nest. Female-biased natal philopatry is unusual among birds but is consistent with the mate-defense mating system of the Upland Sandpiper.

10aBartramia longicauda10adispersal10aExtra-pair paternity10agenetic structure10amating systems10anatal philopatry10ashorebirds10aUpland Sandpiper1 aCasey, A.E.1 aSandercock, B.K.1 aWisely, S.M. uhttps://doi.org/10.1525/cond.2011.10010000538nas a2200157 4500008004100000245007000041210006900111300001100180490000700191100001800198700001600216700001700232700002100249700001700270856009300287 2011 eng d00aHierarchical modeling of lek habitats of Greater Prairie-Chickens0 aHierarchical modeling of lek habitats of Greater PrairieChickens a21 -320 v391 aGregory, A.J.1 aMcNew, L.B.1 aPrebyl, T.J.1 aSandercock, B.K.1 aWisely, S.M. uhttps://www.fws.gov/southwest/es/documents/R2ES/LitCited/LPC_2012/Gregory_et_al_2011.pdf00512nas a2200145 4500008004100000245008000041210006900121300001300190490000700203100001600210700001800226700001700244700002100261856008400282 2011 eng d00aHuman-mediated selection on life-history traits of Greater Prairie-Chickens0 aHumanmediated selection on lifehistory traits of Greater Prairie a255 -2660 v391 aMcNew, L.B.1 aGregory, A.J.1 aWisely, S.M.1 aSandercock, B.K. uhttps://alaska.usgs.gov/science/biology/landbirds/pdfs/McNew_etal_2011_sab2.pdf00573nas a2200145 4500008004100000245013400041210006900175260004300244300001100287490002100298100001800319700002100337700001700358856005200375 2011 eng d00aThe influence of behavioral and landscape ecology on Greater Prairie-Chicken (Tympanuchus cupido) genetic structure and evolution0 ainfluence of behavioral and landscape ecology on Greater Prairie aManhattan, KSbKansas State University a1 -1290 vPhD Dissertation1 aGregory, A.J.1 aSandercock, B.K.1 aWisely, S.M. uhttp://krex.k-state.edu/dspace/handle/2097/853000510nas a2200145 4500008004100000245007800041210006900119300001300188490000700201100001600208700001800224700001700242700002100259856008400280 2011 eng d00aReproductive biology of a southern population of Greater Prairie-Chickens0 aReproductive biology of a southern population of Greater Prairie a209 -2210 v391 aMcNew, L.B.1 aGregory, A.J.1 aWisely, S.M.1 aSandercock, B.K. uhttps://alaska.usgs.gov/science/biology/landbirds/pdfs/McNew_etal_2011_sab1.pdf00490nas a2200133 4500008004100000245006900041210006800110300001300178490000700191100002000198700002100218700002100239856009600260 2011 eng d00aTestosterone mediates mating success in Greater Prairie-Chickens0 aTestosterone mediates mating success in Greater PrairieChickens a195 -2080 v391 aAugustine, J.K.1 aMillspaugh, J.J.1 aSandercock, B.K. uhttp://129.130.186.12/content/testosterone-mediates-mating-success-greater-prairie-chickens00547nas a2200121 4500008004100000245015400041210006900195260005100264490002100315100001600336700002100352856005200373 2010 eng d00aAn analysis of greater prairie-chicken demography in Kansas: the effects of human land use on the population ecology of an obligate grassland species0 aanalysis of greater prairiechicken demography in Kansas the effe aManhattan, KS. 149 ppbKansas State University0 vPhD Dissertation1 aMcNew, L.B.1 aSandercock, B.K. uhttp://krex.k-state.edu/dspace/handle/2097/431602772nas a2200277 4500008004100000245011700041210006900158300001100227490000800238520193700246653002802183653001402211653001602225653002002241653002402261653001402285653002802299653001102327100001602338700001702354700001802371700001802389700002102407700002102428856004502449 2010 eng d00aExposure of nonbreeding migratory shorebirds to cholinesterase inhibiting contaminants in the Western Hemisphere0 aExposure of nonbreeding migratory shorebirds to cholinesterase i a15 -280 v1123 a

Migratory shorebirds frequently forage and roost in agricultural habitats, where they may be exposed to cholinesterase-inhibiting pesticides. Exposure to organophosphorus and carbamate compounds, common anti-cholinesterases, can cause sublethal effects, even death. To evaluate exposure of migratory shorebirds to organophosphorus and carbamates, we sampled birds stopping over during migration in North America and wintering in South America. We compared plasma Cholinesterase activities and body masses of individuals captured at sites with no known sources of organophosphorus or carbamates to those captured in agricultural areas where agrochemicals were recommended for control of crop pests. In South America, plasma acetylcholinesterase and butyrylcholinesterase activity in Buff-breasted Sandpipers was lower at agricultural sites than at reference sites, indicating exposure to organophosphorus and carbamates. Results of plasma Cholinesterase reactivation assays and foot-wash analyses were inconclusive. A meta-analysis of six species revealed no widespread effect of agricultural chemicals on Cholinesterase activity. However, four of six species were negative for acetylcholinesterase and one of six for butyrylcholinesterase, indicating negative effects of pesticides on Cholinesterase activity in a subset of shorebirds. Exposure to Cholinesterase inhibitors can decrease body mass, but comparisons between treatments and hemispheres suggest that agrochemicals did not affect migratory shorebirds' body mass. Our study, one of the first to estimate of shorebirds' exposure to cholinesterase-inhibiting pesticides, suggests that shorebirds are being exposed to cholinesterase-inhibiting pesticides at specific sites in the winter range but not at migratory stopover sites. Future research should examine potential behavioral effects of exposure and identify other potential sites and levels of exposure.

10aBuff-breasted Sandpiper10acarbamate10anonbreeding10aorganophosphate10apopulation declines10asandpiper10aTryngites subruficollis10awaders1 aStrum, K.M.1 aHooper, M.J.1 aJohnson, K.A.1 aLanctot, R.B.1 aZaccagnini, M.E.1 aSandercock, B.K. uhttps://doi.org/10.1525/cond.2010.09002603341nas a2200157 4500008004100000245012500041210006900166300001100235490000700246520268300253100001602936700001802952700001702970700002102987856017503008 2009 eng d00aEstimating the stage of incubation for nests of Greater Prairie-chickens using egg flotation: a float curve for grousers0 aEstimating the stage of incubation for nests of Greater Prairiec a12 -140 v383 aIntroduction Researchers often require accurate estimates of incubation stage for back-calculating the timing of nest initiation or predicting the date of hatching to capture young, to determine the durations of egg-laying, incubation and the construction of breeding phenologies, and to calculate nest productivity. Estimates of nest age are also critical for assessment of the influence of temporal variation in nest survival, and to model daily nest survival as a function of individual-or time-specific covariates (Dinsmore et al. 2002). For example, the timing of nest losses is often related to nest success and the probability of renesting (Schroeder 1997, Pitman et al. 2006, McNew et al. in press). Egg flotation is one of the most common methods employed for estimating stage of embryo development with egg flotation-development relationships documented for many species of birds (Hays & LeCroy 1971, Dunn et al. 1979, Fisher and Sengel 1991, Custer et al. 1992, Brua & Machin 2000, Liebezeit et al. 2007). To our knowledge, there are no published techniques to estimate stage of incubation for nests of grouse. Field biologists estimating stage of incubation for eggs of grouse nests have often used a modified version of an egg flotation technique developed for captive ring-neck pheasants Phasianus colchicus and gray partridges Perdix perdix (Westerskov 1950, Martin & Cooke 1987). It is unknown whether egg flotation can be used to accurately assess age of grouse nests under field conditions. As part of a larger study on the breeding ecology of greater prairie-chickens Tympanuchus cupido; (hereafter "prairie-chickens"), McNew et al. (in press) developed a regression model to accurately predict the stage of incubation for nests from egg flotation angles and egg buoyancy. Methods Prairie-chickens were captured with walk-in traps and drop-nets at leks during March–May of 2006–2008 at three study sites in eastern Kansas, USA (Schroeder & Braun 1991, Silvy et al. 1990). Females were fitted with radio transmitters and located via triangulation >4 times/week during the nesting period (April–July), and daily once it was determined from movement patterns that a female was nesting. Once a female had localized in an area for 3 successive days, we located and flushed the bird so that the eggs could be counted and the nest location recorded with a GPS unit. Females with nests were monitored daily from a distance of >100 m. Nest sites were revisited during incubation to assess clutch size and incubation stage. Figure 1. Estimating the float angle or height of a greater prairie-chicken egg. This egg is floating at ~90° and is not yet buoyant. 1 aMcNew, L.B.1 aGregory, A.J.1 aWisely, S.M.1 aSandercock, B.K. uhttps://www.researchgate.net/publication/228517269_Estimating_the_stage_of_incubation_for_nests_of_Greater_Prairie-Chickens_using_egg_flotation_a_float_curve_for_grousers02412nas a2200229 4500008004100000245009700041210006900138300001100207490000600218520170800224653001601932653002501948653001001973653002101983653001002004653002102014100001602035700001602051700002102067700001702088856007702105 2009 eng d00aHeteroduplex molecules cause sexing errors in a standard molecular protocol for avian sexing0 aHeteroduplex molecules cause sexing errors in a standard molecul a61 -650 v93 a

Molecular methods are a necessary tool for sexing monomorphic birds. These molecular approaches are usually reliable, but sexing protocols should be evaluated carefully because biochemical interactions may lead to errors. We optimized laboratory protocols for genetic sexing of a monomorphic shorebird, the upland sandpiper (Bartramia longicauda), using two independent sets of primers, P2/P8 and 2550F/2718R, to amplify regions of the sex-linked CHD-Z and CHD-W genes. We discovered polymorphisms in the region of the CHD-Z intron amplified by the primers P2/P8 which caused four males to be misidentified as females (n = 90 mated pairs). We cloned and sequenced one CHD-W allele (370 bp) and three CHD-Z alleles in our population: Z° (335 bp), Z′ (331 bp) and Z″ (330 bp). Normal (Z°Z°) males showed one band in agarose gel analysis and were easily differentiated from females (Z°W), which showed two bands. However, males heterozygous for CHD-Z alleles (Z′Z″) unexpectedly showed two bands in a pattern similar to females. While the Z′ and Z″ fragments contained only short deletions, they annealed together during the polymerase chain reaction (PCR) process and formed heteroduplex molecules that were similar in size to the W fragment. Errors previously reported for molecular sex-assignment have usually been due to allelic dropout, causing females to be misidentified as males. Here, we report evidence that events in PCRs can lead to the opposite error, with males misidentified as females. We recommend use of multiple primer sets and large samples of known-sex birds for validation when designing protocols for molecular sex analysis.

10a2550F/2718R10aBartramia longicauda10aCHD-Z10amolecular sexing10aP2/P810aUpland Sandpiper1 aCasey, A.E.1 aJones, K.L.1 aSandercock, B.K.1 aWisely, S.M. uhttps://onlinelibrary.wiley.com/doi/abs/10.1111/j.1755-0998.2008.02307.x02329nas a2200133 4500008004100000245009800041210006900139300001300208490000700221520185300228100001902081700002102100856007402121 2008 eng d00aCowbird removals unexpectedly increase productivity of a brood parasite and the songbird host0 aCowbird removals unexpectedly increase productivity of a brood p a537 -5480 v183 a

Generalist brood parasites reduce productivity and population growth of avian hosts and have been implicated in population declines of several songbirds of conservation concern. To estimate the demographic effects of brood parasitism on Bell's Vireos (Vireo bellii), we removed Brown-headed Cowbirds (Molothrus ater) in a replicated switchback experimental design. Cowbird removals decreased parasitism frequency from 77% and 85% at unmanipulated plots to 58% and 47% at removal plots in 2004 and 2005, respectively. Vireo productivity per pair was higher at cowbird removal plots when years were pooled (mean = 2.6 ± 0.2 [SE] young per pair) compared to unmanipulated plots (1.2 ± 0.1). Nest desertion frequency was lower at cowbird removal plots (35% of parasitized nests) compared to unmanipulated plots (69%) because removal of host eggs was the proximate cue for nest desertion, and vireos experienced lower rates of egg loss at cowbird removal plots. Nest success was higher among unparasitized than parasitized nests, and parasitized nests at cowbird removal plots had a higher probability of success than parasitized nests at unmanipulated plots. Unexpectedly, cowbird productivity from vireo pairs was higher at cowbird removal plots (mean = 0.3 ± 0.06 young per pair) than at unmanipulated plots (0.1 ± 0.03) because fewer parasitized nests were deserted and the probability of nest success was higher. Our study provides the first evidence that increases in cowbird productivity may be an unintended consequence of cowbird control programs, especially during the initial years of trapping when parasitism may only be moderately reduced. Thus, understanding the demographic impacts of cowbird removals requires an informed understanding of the behavioral ecology of host–parasite interactions.

1 aKosciuch, K.L.1 aSandercock, B.K. uhttps://esajournals.onlinelibrary.wiley.com/doi/abs/10.1890/07-0984.102690nas a2200229 4500008004100000245007500041210006900116300001300185490000700198520188200205653002402087653001402111653003502125653002102160653001002181653001302191100002102204700001702225700001902242700002002261856017902281 2008 eng d00aDemographic sensitivity of population change in the Northern Bobwhite0 aDemographic sensitivity of population change in the Northern Bob a970 -9820 v723 a

The northern bobwhite (Colinus virginianus) is an economically important gamebird that is currently undergoing widespread population declines. Despite considerable research on the population ecology of bobwhites, there have been few attempts to model population dynamics of bobwhites to determine the contributions of different demographic parameters to variance of the finite rate of population change (λ). We conducted a literature review and compiled 405 estimates of 9 demographic parameters from 49 field studies of bobwhites. To identify demographic parameters that might be important for management, we used life-stage simulation analyses (LSA) to examine sensitivity of λ to simulated variation in 9 demographic parameters for female bobwhites. In a baseline LSA based on uniform distributions bounded by the range of estimates for each demographic parameter, bobwhite populations were predicted to decline (λ = 0.56) and winter survival of adults made the greatest contribution to variance of λ (r2 = 0.453), followed by summer survival of adults (r2 = 0.163), and survival of chicks (r2 = 0.120). Population change was not sensitive to total clutch laid, nest survival, egg hatchability, or 3 parameters associated with the number of nesting attempts (r2 <0.06). Our conclusions were robust to alternative simulation scenarios, and parameter rankings changed only if we adjusted the lower bounds of winter survival upwards. Bobwhite populations were not viable with survival rates reported from most field studies. Survival rates may be depressed below sustainable levels by environmental conditions or possibly by impacts of capture and telemetry methods. Overall, our simulation results indicate that management practices that improve seasonal survival rates will have the greatest potential benefit for recovery of declining populations of bobwhites.

10aColinus virginianus10afecundity10alife-stage simulation analysis10apopulation model10aquail10asurvival1 aSandercock, B.K.1 aJensen, W.E.1 aWilliams, C.K.1 aApplegate, R.D. uhttps://bioone.org/journals/journal-of-wildlife-management/volume-72/issue-4/2007-124/Demographic-Sensitivity-of-Population-Change-in-Northern-Bobwhite/10.2193/2007-124.short02567nas a2200229 4500008004100000245010800041210006900149300001300218490000800231520185700239653002502096653001502121653001402136653001502150653001902165653001702184653002002201100002102221700001702242700001902259856005902278 2008 eng d00aEffects of experimental cowbird removals on brood parasitism and nest predation in a grassland songbird0 aEffects of experimental cowbird removals on brood parasitism and a820 -8300 v1253 a

Brood parasitism and predation are two factors that limit seasonal fecundity in grassland songbirds. We removed Brown-headed Cowbirds (Molothrus ater) in a switchback experiment to examine the effects of brood parasitism and nest predation on the productivity of Dickcissels (Spiza americana). Nesting Dickcissels were monitored at four study plots in northeast Kansas in a two-year study. Brown-headed Cowbirds were captured with drop-in traps at two removal plots, two unmanipulated plots were reference plots, and treatments were reversed between years. To evaluate the effect of Brown-headed Cowbird removals, we compared the percentage of nests parasitized, rates of multiple parasitism, clutch size, daily nest survival rates, and overall productivity per nest between removal and reference plots. Removals of Brown-headed Cowbirds successfully reduced the probability of parasitism and rates of multiple parasitism, but only in one of two years. Brown-headed Cowbirds did not appear to contribute to nest losses, given that few nests were abandoned because of cowbird activity and that the probabilities of nest parasitism and nest survival declined simultaneously over the breeding season. Overall, nest productivity showed no difference between treatments in either year, despite reduced rates of parasitism at removal plots in 2004. High rates of nest predation minimized the potential benefits of Brown-headed Cowbird removals for increasing productivity of Dickcissels. Our results demonstrate that removals can reduce parasitism levels but that the success of removal programs may vary annually, particularly in regions where Brown-headed Cowbirds and nest predators are abundant. Management actions that minimize parasitism and predation by modifying habitat structure may provide better alternatives to programs based on removals.

10abrown-headed cowbird10aDickcissel10afecundity10amanagement10aMolothrus ater10aproductivity10aSpiza americana1 aSandercock, B.K.1 aHewett, E.L.1 aKosciuch, K.L. uhttps://academic.oup.com/auk/article/125/4/820/514820602446nas a2200193 4500008004100000245013500041210006900176300001500245490000700260520178400267653001602051653002702067653001602094653001702110653002102127100001702148700002102165856006602186 2008 eng d00aPhenotypic correlates and survival consequences of male mating success in lek-mating Greater Prairie-chickens (Tympanuchus cupido)0 aPhenotypic correlates and survival consequences of male mating s a1377 -13880 v623 a

Female choice and male–male aggression are two modes of sexual selection that can lead to elaboration of male morphological and behavioral traits. In lek-mating species, male mating success is often strongly skewed, and it is puzzling why variation in male traits is still observed given directional female choice. If male traits correlated with reproductive success are honest signals of male quality, there may be survival costs associated with the expression of those traits. In this study, we examined whether morphological, behavioral, and territorial traits are correlated with male mating success and survival in the lek-mating greater prairie-chicken (Tympanuchus cupido). We introduce a novel application of multinomial discrete choice models for analysis of female mate choice behavior. We found that behavioral and territorial attributes showed 6.5 times more variability among males than morphological traits. Both display and aggressive behaviors were strong predictors of male mating success, suggesting that both female choice and male–male aggression were important in determining mating success among male greater prairie-chickens. Moreover, annual survival of male prairie-chickens was independent of mating success and male traits. Females appear to be choosing males based on behavioral traits where large variation exists between males (coefficient of variation >30%). Behavioral traits were the most important factor in determining mating success of male prairie-chickens, but the mechanism underlying this relationship is unknown. In the future, experimental manipulations of male hormones or parasite loads could bridge the proximate mechanisms and ultimate consequences of factors mediating male mating success in lek-mating grouse.

10aGalliformes10aLife history trade-off10amate choice10areproduction10aSexual selection1 aNooker, J.K.1 aSandercock, B.K. uhttps://link.springer.com/article/10.1007%2Fs00265-008-0566-802610nas a2200277 4500008004100000245010600041210006900147300001300216490001500229520168500244100001601929700001501945700001401960700001701974700001801991700001802009700002102027700001502048700001502063700001602078700001602094700002102110700002302131700002102154856015702175 2008 eng d00aPlasma cholinesterases for monitoring pesticide exposure in Nearctic-Neotropical migratory shorebirds0 aPlasma cholinesterases for monitoring pesticide exposure in Near a641 -6510 v19 (Suppl)3 aOrganophosphorus (OP) and carbamate (CB) pesticides are commonly used agrochemicals throughout the Western Hemisphere. These pesticides have caused mortalities in migratory birds and adverse physiological effects in trials with captive birds. Migratory shorebirds use a variety, of habitats during the austral summer in temperate South America and during migration through the Great Plains of the United States. Habitats where risk of exposure is high include rice fields and turf grass farms where agrochemicals are used. Cholinesterase (ChE) is a specific biomarker for monitoring OP and CB exposure and can be measured using standard laboratory procedures. Plasma ChE activity is useful as a non-lethal means of monitoring avian exposure to OP and CB pesticides. Many variables can affect enzyme activity and reactivation assays are not always possible, thus reference ChE values are a necessary component of monitoring exposure. During northbound migration in 2006, we sampled four upland and five wetland shore-bird species at four pesticide-free sites in North America, characterizing and measuring plasma ChEs in all shorebird species. Small-bodied species had higher levels of ChE activity in plasma than large-bodied species. Acetylcholinesterase (AChE), the enzyme whose inhibition leads to poisoning symptoms, showed less inter-specific variation than butyrylcholinesterase (BChE). Plasma ChE activities varied with date of capture in three of five species. Sex differences were significant in one of two species tested. Our baseline ChE values for migratory shorebirds provide a framework for future ecotoxicological studies of Nearctic-Neotropical migrant shorebirds.1 aStrum, K.M.1 aAlfaro, M.1 aHaase, B.1 aHooper, M.J.1 aJohnson, K.A.1 aLanctot, R.B.1 aLesterhuis, A.J.1 aLópez, L.1 aMatz, A.C.1 aMorales, C.1 aPaulson, B.1 aSandercock, B.K.1 aTorres-Dowdall, J.1 aZaccagnini, M.E. uhttps://www.researchgate.net/publication/254414753_Plasma_cholinesterases_for_monitoring_pesticide_exposure_in_Nearctic-Neotropical_migratory_shorebirds00508nas a2200157 4500008004100000245006200041210006200103300001100165490000800176100002100184700001600205700001600221700001300237700001900250856008100269 2008 eng d00aReovirus associated with mortality of an Upland Sandpiper0 aReovirus associated with mortality of an Upland Sandpiper a60 -610 v1151 aSandercock, B.K.1 aCasey, A.E.1 aGreen, D.E.1 aIp, H.S.1 aConverse, K.A. uhttp://129.130.186.12/content/reovirus-associated-mortality-upland-sandpiper02315nas a2200229 4500008004100000245010900041210006900150300001300219490000700232520151000239653001101749653002301760653005301783653001301836653001201849653002701861100002001888700001501908700001901923700002101942856012201963 2008 eng d00aResponses of two bunchgrasses to nitrogen addition in tallgrass prairie: the role of bud bank demography0 aResponses of two bunchgrasses to nitrogen addition in tallgrass  a672 -6800 v953 aGrowth of tallgrass prairie plants, many of which maintain substantial bud banks, can be limited by nitrogen (N), water, and/or light. We hypothesized that tallgrass prairie plants respond to increases in N through demographic effects on the bud bank. We tested the effects of a pulse of N on (1) bud bank demography, (2) plant reproductive allocation, and (3) ramet size. We parameterized matrix models, considering each genet as a population of plant parts. Nitrogen addition significantly impacted bud bank demography in two subdominant species of bunchgrass: Sporobolus heterolepis (a C4 grass) and Koeleria macrantha (a C3 grass), but had no effect on the size of individual ramets. Emergence from the bud bank and ramet population growth rates (λ) were significantly higher in S. heterolepis genets that received supplemental N. Nitrogen addition also affected the bud demography of K. macrantha, but N addition decreased rather than increased λ. Prospective and retrospective demographic analyses indicated that bud bank dynamics were the most important demographic processes driving plant responses to nutrient availability. Thus, the variation in productivity in these tallgrass prairie species is driven principally by the demography of the bud bank rather than by the physiology and growth of aboveground tillers. Improved understanding of bud bank dynamics may lead to improved predictive models of grassland responses to environmental changes such as altered N deposition and precipitation.10akansas10aKoeleria macrantha10aKonza Prairie Long-Term Ecological Research Site10aMeristem10aPoaceae10aSporobolus heterolepis1 aDalgleish, H.J.1 aKula, A.R.1 aHartnett, D.C.1 aSandercock, B.K. uhttp://129.130.186.12/content/responses-two-bunchgrasses-nitrogen-addition-tallgrass-prairie-role-bud-bank-demography02071nas a2200145 4500008004100000245012100041210006900162300001300231490000700244520154000251100001901791700001701810700002101827856007701848 2008 eng d00aStable isotopes identify the natal origins of a generalist brood parasite, the brown‐headed cowbird Molothrus ater0 aStable isotopes identify the natal origins of a generalist brood a364 -3670 v393 a

Identifying the natal origins of brood parasites is a major challenge that usually requires labor-intensive searching for nests of host species. Stable isotope analysis of feathers and other body tissues of parasitic young could be a possible tool for determining natal origins if tissues reflect the isotopic composition of the diet fed to nestlings. We measured the carbon (13C) and nitrogen (15N) isotope compositions of feathers for two age-classes of brown-headed cowbirds Molothrus ater at the Konza Prairie Biological Station near Manhattan, Kansas: nestlings raised by five species of songbird hosts in two different habitats, and juveniles captured after independence. Isotope values from cowbird nestlings did not differ among host species and we were unable to assign juvenile cowbirds to their natal hosts. However, nestlings raised in grassland habitat had feathers that contained significantly higher δ13C values and lower δ15N values than nestlings raised in shrub habitats. In addition, independent juveniles had isotopic signatures that were similar to cowbird nestlings raised on shrub habitats. Although dickcissel Spiza americana comprised the majority of samples from shrub habitats, our conclusions reflect the natural pattern of parasitism at the site and should be representative of cowbirds raised at Konza. We conclude that stable isotope analysis of feathers is effective for determining the natal origins of parasitic young if isotope values from nestlings are isotopically distinct among habitats.

1 aKosciuch, K.L.1 aRivers, J.W.1 aSandercock, B.K. uhttps://onlinelibrary.wiley.com/doi/abs/10.1111/j.0908-8857.2008.04170.x02016nas a2200229 4500008004100000245007600041210006900117300001300186490000700199520128200206653001901488653001501507653003501522653001701557653002701574653001201601653002101613100001501634700001801649700002101667856009801688 2007 eng d00aDemographic response of a grassland rodent to environmental variability0 aDemographic response of a grassland rodent to environmental vari a982 -9880 v883 aWe used stage-structured matrix population models, derived from 3 years with disparate levels of precipitation, to assess the potential effects of climate change on annual population growth (λ) of deer mice (Peromyscus maniculatus). Populations of deer mice increased during a year of normal precipitation (λ = 1.69 ± 0.02 SE) and a wet year (λ = 1.03 ± 0.02), but declined in a dry year (λ = 0.34 ± 0.02). Life-table response experiment analyses indicated that reduced survival of adults in the dry year, and reduced survival of pups and juveniles in the wet year, exerted the greatest influence on variation in population growth. Stochastic models that projected populations of deer mice for a 50-year period predicted that populations would not be able to persist if mean annual precipitation was reduced ≥11% by increasing the frequency of dry years. Furthermore, the stochastic population growth rate declined more quickly when the probability of a normal year was reduced, simulating increased variability in rainfall, relative to other scenarios examined. Our stochastic models indicate that a relatively small reduction in mean precipitation could result in substantial population declines of P. maniculatus in the mixed-grass prairie of central North America.10aClimate change10adeer mouse10alife-table response experiment10amatrix model10aPeromyscus maniculatus10aprairie10astochastic model1 aReed, A.W.1 aKaufman, G.A.1 aSandercock, B.K. uhttp://129.130.186.12/content/demographic-response-grassland-rodent-environmental-variability02793nas a2200229 4500008004100000245009700041210006900138300001300207490000700220520205500227653002502282653000902307653001202316653001102328653002102339653001402360653001302374653002102387100001502408700002102423856011902444 2007 eng d00aOptimizing radio retention andminimizing radio impacts in a field study of Upland Sandpipers0 aOptimizing radio retention andminimizing radio impacts in a fiel a971 -9800 v713 aTwo challenges in wildlife telemetry are optimizing the duration of transmitter attachment and minimizing the impacts of radios on the behavior and demography of the study animal. We tested 4 methods of radio attachment for a breeding population of upland sandpipers (Bartramia longicauda) under natural conditions at a tallgrass prairie site in Kansas, USA. To estimate radio retention and weekly survival rates, we used the nest survival model of Program MARK. Radio retention was lowest at the start and the end of the breeding period. The expected duration of radio retention was 1.8 years for a leg-loop harness, 40 days for radios glued to clipped feathers, 26 days for radios glued directly to feathers, and 7 days for radios glued to bare skin. Few radiomarked birds died during our study, but 4 of 8 mortality events were discovered within one week of radiomarking. Both glue and harnesses increased predation risk immediately after radio attachment. The weekly probability of survival was high after a 1-week acclimation period, and the expected survival for a 10-week breeding period was similar in males and females. Attachment of radios with glue had no effect on annual return rates. However, attachment of radios with leg harnesses resulted in lower return rates among radiomarked birds than birds without radios. Radios attached with glue were shed in <1 year but radios attached with harnesses were retained for up to 1–2 years. Our results indicate a tradeoff between optimizing radio retention and minimizing impacts on demography. Glue techniques had retention rates that were suitable for only short-term studies, but attachment with glue had no long-term effect on annual return rates. Leg harnesses provided effective radio retention that had little effect on survival rates during the stationary breeding period, but resulted in lower annual return rates. Robust estimates of radio retention and survival will assist researchers in selecting attachment techniques that best meet the study goals of future telemetry projects.10aBartramia longicauda10aglue10aharness10akansas10aradio attachment10ashorebird10asurvival10aUpland Sandpiper1 aMong, T.W.1 aSandercock, B.K. uhttp://129.130.186.12/content/optimizing-radio-retention-andminimizing-radio-impacts-field-study-upland-sandpipers02465nas a2200229 4500008004100000245010300041210006900144300001300213490000700226520172500233653001501958653001601973653001901989653001002008653001302018653001702031100001802048700001602066700002102082700001902103856011302122 2006 eng d00aEffects of rangeland management on community dynamics of the herpetofauna of the tallgrass prairie0 aEffects of rangeland management on community dynamics of the her a378 -3880 v623 aThe Flint Hills of Kansas and Oklahoma are the largest remaining tracts of tallgrass prairie in North America. This area has undergone major changes in land management practices in the past 30 years. Traditional season-long cattle stocking with variable burn schedules has diversified to include intensive-early cattle stocking accompanied by annual burning. To understand how different land management practices affect the herpetofauna of a tallgrass prairie, we used mark-recapture statistics to analyze herpetofaunal community dynamics. We analyzed survey data collected over a 15-year time span (1989–2003) from a rangeland site in Cowley County, KS, USA. A modified Jolly-Seber open population model, POPAN-5, was used to estimate four community parameters: probability of species loss (φ′), probability of detection (P), probability of entry (Pent), and species richness (N). The top models included burn status as a covariate for species loss rate, while cattle stocking received moderate support as a covariate. Rates of species loss were higher during burn years (φ′  =  0.04, 95% CI: 0.02 to 0.08) than nonburn years (φ′  =  0.00, 95% CI: 0.00 to 0.01). Analysis of the impacts of different management practices was difficult due to confounding effects of changes in both burning and grazing. Declines in species richness tended to be steepest during a period of season-long stocking, but results were not statistically significant. Though our limited data set does not allow us to draw strong conclusions on the effects of land management on herpetofaunal populations, the mark-recapture models illustrated in our study should prove to be a valuable tool in future analyses of similar data.10aAmphibians10aFlint Hills10aMark-recapture10aPOPAN10aReptiles10aSpecies loss1 aWilgers, D.J.1 aHorne, E.A.1 aSandercock, B.K.1 aVolkmann, A.W. uhttp://129.130.186.12/content/effects-rangeland-management-community-dynamics-herpetofauna-tallgrass-prairie03031nas a2200241 4500008004100000245008300041210006900124300001500193490000700208520226400215653002202479653002402501653001602525653001702541653002202558653001602580653001602596653001802612653002202630653001402652100002102666856010202687 2006 eng d00aEstimation of demographic parameters from liveencounter data: a summary review0 aEstimation of demographic parameters from liveencounter data a s a1504 -15200 v703 aEstimation of demographic parameters is central to research questions in wildlife management, conservation, and evolutionary ecology. I review the 7 major classes of mark–recapture models that investigators can use to estimate apparent survival and other parameters from live-encounter data. Return rates are the product of 4 probabilities: true survival (S), site fidelity (F), site propensity (δ), and true detection (p*). Cormack-Jolly-Seber (CJS) models improve upon return rates by separating apparent survival (ϕ = S × F) from the probability of encounter (p = δ × p*). The main drawback to mark–recapture models based on live-encounter data is that the complement of apparent survival (1 − ϕ) includes losses to mortality and to permanent emigration, and these 2 ecological processes are difficult to disentangle. Advanced mark–recapture models require additional sampling effort but estimate apparent survival with greater precision and less bias, and they also offer estimates of other useful demographic parameters. Time-since-marking or transient models control for individuals not encountered after the occasion they are first marked, a common feature of wildlife populations. Temporal symmetry models combine forward- and reverse-time modeling to estimate recruitment (f) and the finite rate of population change (λ). Multi-strata models include dynamic categorical information and offer state-specific estimates of apparent survival and encounter rates, as well as probabilities of changing states (Ψ). Robust design models subdivide sampling occasions into shorter periods, and they partition encounter rates (p) into estimates of temporary emigration (γ = 1 − δ) and true detection (p*). Joint models combine live encounters with other sources of information, including dead-recovery data, and decompose apparent survival into estimates of true survival (S) and site fidelity (F). Cormack-Jolly-Seber and multi-strata models have a large literature, but many of the advanced models have not yet received widespread use. In the future, wildlife ecologists should design field studies that take advantage of the best possible statistical procedures now that a range of alternative models and software tools are available.10aapparent survival10aCormack-Jolly-Seber10ajoint model10amulti-strata10apopulation change10arecruitment10areturn rate10arobust design10atemporal symmetry10atransient1 aSandercock, B.K. uhttp://129.130.186.12/content/estimation-demographic-parameters-liveencounter-data-summary-review02298nas a2200229 4500008004100000245009000041210006900131300001300200490000700213520153200220653001701752653002501769653001801794653002101812653003201833653001901865653001701884100001901901700001701920700002101937856011001958 2006 eng d00aNest desertion bya cowbird host: an anti-parasite behavior or a response to egg loss?0 aNest desertion bya cowbird host an antiparasite behavior or a re a917 -9240 v173 aNatural selection can favor songbirds that desert nests containing eggs of the parasitic brown-headed cowbird (Molothrus ater). However, the high variability in desertion of parasitized nests within species is perplexing in light of the typically high costs of parasitism. Because nest desertion can also be a response to partial clutch predation, we first asked if Bell's vireos (Vireo bellii) deserted nests in response to the presence of cowbird eggs (antiparasite response hypothesis) or to egg removal by predators and female cowbirds (egg predation hypothesis). Second, we asked whether variation in nest desertion was due to intrinsic differences among individuals or to variation in nest contents. We monitored a large number of nests (n = 494) and performed a clutch manipulation experiment to test these hypotheses. The number of vireo eggs that remained in a nest was a strong predictor of desertion both within and among pairs. Neither the presence of a single cowbird egg, which leads to nest failure for this host, nor the number of cowbird eggs received in a vireo nest influenced nest desertion. Furthermore, vireos did not desert experimental nests when we immediately exchanged cowbird eggs for vireo eggs but deserted if we removed vireo eggs and replaced them with cowbird eggs the following morning. Desertion of parasitized nests by Bell's vireos can be almost entirely explained as a response to partial or complete clutch loss and does not appear to have been altered by selection from brood parasitism.10aBell's Vireo10abrown-headed cowbird10aegg predation10aevolutionary lag10ahost–parasite coevolution10aMolothrus ater10aVireo bellii1 aKosciuch, K.L.1 aParker, T.H.1 aSandercock, B.K. uhttp://129.130.186.12/content/nest-desertion-bya-cowbird-host-anti-parasite-behavior-or-response-egg-loss01473nas a2200133 4500008004100000245005300041210005300094300001300147490000700160520105700167100001701224700002101241856007701262 2004 eng d00aPredation by gray catbird on brown thrasher eggs0 aPredation by gray catbird on brown thrasher eggs a101 -1030 v493 a

The gray catbird (Dumetella carolinensis) has been documented visiting and breaking the eggs of artificial nests, but the implications of such observations are unclear because there is little cost in depredating an undefended nest. During the summer of 2001 at Konza Prairie Biological Station, Kansas, we videotaped a gray catbird that broke and consumed at least 1 egg in a brown thrasher (Toxostoma rufum) nest. Our observation was consistent with egg predation because the catbird consumed the contents of the damaged egg after breaking it. The large difference in body mass suggests that a catbird (37 g) destroying eggs in a thrasher (69 g) nest might risk injury if caught in the act of predation and might explain why egg predation by catbirds has been poorly documented. Our observation indicated that the catbird should be considered as an egg predator of natural nests and that single-egg predation of songbird nests should not be attributed to egg removal by female brown-headed cowbirds (Molothrus ater) without additional evidence.

1 aRivers, J.W.1 aSandercock, B.K. uhttp://129.130.186.12/content/predation-gray-catbird-brown-thrasher-eggs