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/art7/02542nas a2200289 4500008004100000245011500041210006900156300001300225490000800238520164800246653002401894653001701918653002101935653003101956653001501987653001302002653001902015653002402034653002502058653002002083653001702103100001702120700001702137700001902154700002002173856005902193 2010 eng d00aCommunity-level patterns of host use by the Brown-headed Cowbird (Molothrus ater), a generalist brood parasite0 aCommunitylevel patterns of host use by the Brownheaded Cowbird M a263 -2730 v1273 a

Quantifying community-level host use by generalist brood parasites is important because it provides a measure of the resources that parasites need for reproduction. During the 2002–2007 breeding seasons, we quantified host use by the Brown-headed Cowbird (Molothrus ater) at Konza Prairie Biological Station in northeast Kansas. Overall, 54.4% of nests (n = 2,621) of 22 passerine host species that typically accept parasitic eggs were parasitized, and parasitized nests contained an average of 1.9 ± 1.03 (SD) Brown-headed Cowbird eggs, nestlings, or both. Multiple parasitism was common on the study site in all years: 55.7% of parasitized nests (n = 1,425) received ≥2 Brown-headed Cowbird eggs. The Bell's Vireo (Vireo bellii; 70.5%) and the Dickcissel (Spiza americana; 69.6%) were parasitized at a significantly greater rate than the Red-winged Blackbird (Agelaius phoeniceus, 21.9%); collectively, these three species represented 85.8% of potential host nests found in all years. The host preference of Brown-headed Cowbirds did not appear to shift among the three species and instead they exhibited a consistent preference for Dickcissel nests over the course of the breeding season and among years. Both the rate and the intensity of parasitism on Dickcissels were significantly lower during the present study than in one conducted several decades earlier at the same site. Our results indicate that cowbirds in northeast Kansas differentially parasitize hosts, that most cowbird eggs are laid in the nests of a small number of host species, and that the Dickcissel appears to be preferred over other hosts.

10aAgelaius phoeniceus10aBell's Vireo10abrood parasitism10acommunity-level parasitism10aDickcissel10ahost use10aMolothrus ater10amultiple parasitism10ared-winged blackbird10aSpiza americana10aVireo bellii1 aRivers, J.W.1 aJensen, W.E.1 aKosciuch, K.L.1 aRothstein, S.I. uhttps://academic.oup.com/auk/article/127/2/263/514838202690nas 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.short02358nas a2200265 4500008004100000245007900041210006900120300001300189490000800202520160700210653001201817653001201829653001501841653001801856653001701874653001801891653002001909100001701929700001801946700001701964700001901981700001602000700001702016856005902033 2008 eng d00aGeographic patterns of song similarity in the Dickcissel (Spiza americana)0 aGeographic patterns of song similarity in the Dickcissel Spiza a a953 -9640 v1253 a

Song sharing among neighboring males is a well-known, frequent outcome of song learning in oscine passerines and some other groups, but only limited investigations of the spatial scale of this phenomenon have been pursued. On the basis of recordings of 1,043 individuals, we investigated song sharing in Dickcissels (Spiza americana) at local and regional scales at sites from northern Kansas to northern Oklahoma. Classification of song elements revealed decreasing song similarity with increasing distances between individual birds at small to intermediate scales, to ~10 km. At the largest spatial scales (10–300 km between sites), there was very little similarity among sites and no obvious tendency for a decrease in similarity with increasing distances among our 30 sites. At our intensively sampled site, analyses of quantitative measurements showed that, at least for our most widely shared song element, frequency and duration were more similar in closer birds. Thus, distance between birds influences both quantitative and qualitative song similarity in Dickcissels. Variability existed among sites in the shape of the song-sharing decay curve, which indicates that other factors besides distance also govern song-sharing patterns. We found high repeatability of individual songs for both second-year (SY) and after-second-year (ASY) males throughout the season, and high conformity to the local song neighborhood in both SY and ASY males from their first recording soon after arrival in May. Returning ASY males sang the same song they had produced the previous breeding season.

10aculture10adialect10aDickcissel10aPasseriformes10asong sharing10aspatial scale10aSpiza americana1 aSchook, D.M.1 aCollins, M.D.1 aJensen, W.E.1 aWilliams, P.J.1 aBader, N.E.1 aParker, T.H. uhttps://academic.oup.com/auk/article/125/4/953/514817003703nas a2200193 4500008004100000245010100041210006900142300001300211490000800224520302200232653001703254653002803271653001103299653001903310653002003329100001703349700001603366856012703382 2005 eng d00aDensity-dependent habitatselection by Brown-headed Cowbirds (Molothrus ater) in tallgrassprairie0 aDensitydependent habitatselection by Brownheaded Cowbirds Moloth a136 -1490 v1423 aLocal distributions of avian brood parasites among their host habitats may depend upon conspecific parasite density. We used isodar analysis to test for density-dependent habitat selection in brown-headed cowbirds (Molothrus ater) among tallgrass prairie adjacent to wooded edges, and prairie interior habitat (>100 m from wooded edges) with and without experimental perches. Eight study sites containing these three habitat treatments were established along a geographical gradient in cowbird abundance within the Flint Hills region of Eastern Kansas and Oklahoma, USA. The focal host species of our study, the dickcissel (Spiza americana), is the most abundant and preferred cowbird host in the prairie of this region. Cowbird relative abundance and cowbird:host abundance ratios were used as estimates of female cowbird density, whereas cowbird egg density was measured as parasitism frequency (percent of dickcissel nests parasitized), and parasitism intensity (number of cowbird eggs per parasitized nest). Geographical variation in cowbird abundance was independent of host abundance. Within study sites, host abundance was highest in wooded edge plots, intermediate in the experimental perch plots, and lowest in prairie interior. Cowbirds exhibited a pattern of density-dependent selection of prairie edge versus experimental perch and interior habitats. On sites where measures of cowbird density were lowest, all cowbird density estimates (female cowbirds and their eggs) were highest near (≤100 m) wooded edges, where host and perch availability are highest. However, as overall cowbird density increased geographically, these density estimates increased more rapidly in experimental perch plots and prairie interiors. Variation in cowbird abundance and cowbird:host ratios suggested density-dependent cowbird selection of experimental perch over prairie interior habitat, but parasitism levels on dickcissel nests were similar among these two habitats at all levels of local cowbird parasitism. The density-dependent pattern of cowbird distribution among prairie edge and interior suggested that density effects on perceived cowbird fitness are greatest at wooded edges. A positive relationship between daily nest mortality rates of parasitized nests during the nestling period with parasitism intensity levels per nest suggested a density-dependent effect on cowbird reproductive success. However, this relationship was similar among habitats, such that all habitats should have been perceived as being equally suitable to cowbirds at all densities. Other unmeasured effects on cowbird habitat suitability (e.g., reduced cowbird success in edge-dwelling host nests, cowbird despotism at edges) might have affected cowbird habitat selection. Managers attempting to minimize cowbird parasitism on sensitive cowbird hosts should consider that hosts in otherwise less-preferred cowbird habitats (e.g., habitat interiors) are at greater risk of being parasitized where cowbirds become particularly abundant.10aEdge effects10aIdeal free distribution10aIsodar10aMolothrus ater10aSpiza americana1 aJensen, W.E.1 aCully, J.F. uhttp://lter.konza.ksu.edu/content/density-dependent-habitatselection-brown-headed-cowbirds-molothrus-ater-tallgrassprairie02369nas a2200205 4500008004100000245014500041210006900186300001300255490000800268520160400276653002101880653002501901653001501926653002501941653001901966653002001985100001702005700001602022856012502038 2005 eng d00aGeographic variation in Brown-headed Cowbird (Molothrus ater) parasitism on Dickcisssels (Spiza americana) in Great Plains tallgrass prairie0 aGeographic variation in Brownheaded Cowbird Molothrus ater paras a648 -6600 v1223 aThe incidence of brood parasitism by Brown-headed Cowbirds (Molothrus ater; hereafter “cowbirds“) within host species typically reflects the continental pattern in cowbird abundance across North America, where parasitism is heaviest in the Great Plains. However, we found considerable variation in cowbird parasitism on Dickcissel (Spiza americana) nests within a subregion of the Great Plains (the Flint Hills), where the highest levels of cowbird parasitism on grassland bird nests had been previously reported. Local parasitism frequencies on Dickcissel nests varied latitudinally across the Flint Hills, ranging from 0% to 92% of nests parasitized. Interestingly, we found no obvious patterns in habitat or host attributes that were associated with this steep geographic gradient in brood parasitism. Cowbird parasitism on Dickcissel nests was not correlated with the vertical density of local prairie vegetation, mean nest distance to edge, proportion of forest to grassland habitat surrounding study sites (≤5 to 10 km), geographic variation in host abundance, or Dickcissel density or nest initiation dates. Parasitism frequencies and intensities (number of cowbird eggs per parasitized nest) on Dickissel nests were only significantly related to variation in local female cowbird density. Dickcissel clutch size and apparent fledging success were negatively correlated with local cowbird parasitism levels. Geographic patterns in cowbird abundance within and among regions should be considered when establishing conservation areas for grassland birds or other cowbird hosts of concern.10abrood parasitism10abrown-headed cowbird10aDickcissel10ageographic variation10aMolothrus ater10aSpiza americana1 aJensen, W.E.1 aCully, J.F. uhttp://lter.konza.ksu.edu/content/geographic-variation-brown-headed-cowbird-molothrus-ater-parasitism-dickcisssels-spiza00509nas a2200109 4500008004100000245012900041210006900170260004300239490001400282100001700296856008600313 2003 eng d00aSpatial variation in brown-headed cowbird(Molothrus ater) abundance and brood parasitism in the Flint Hillstallgrass prairie0 aSpatial variation in brownheaded cowbirdMolothrus ater abundance aManhattan, KSbKansas State University0 vMS Thesis1 aJensen, W.E. uhttps://www.k-state.edu/kscfwru/files/alumni/William%20E.%20Jensen%20Abstract.pdf