Condor最新文献

{"title":"Short-term riparian restoration success measured by territory density and reproductive success of three songbirds along the Trinity River, California","authors":"Jaime L. Stephens, Sarah M. Rockwell","doi":"10.1093/condor/duz043","DOIUrl":"https://doi.org/10.1093/condor/duz043","url":null,"abstract":"ABSTRACT Water crises and endangered salmon are pressing environmental concerns influencing restoration decisions in the western United States. When instream restoration necessitates initial loss of riparian cover to restore floodplain function, a short-term goal to minimize harm to riparian-associated wildlife is a worthwhile benchmark. From 2012 to 2015, we examined short-term restoration success, as measured by territory characteristics and reproductive success in restored and reference sites, for 3 riparian bird species (Song Sparrow [Melospiza melodia], Yellow-breasted Chat [Icteria virens], and Yellow Warbler [Setophaga petechia]) along a 64 km stretch of the Trinity River, California. Territory size had the highest relative variable importance in sets of candidate models explaining territory density for all 3 species, and was inversely related to territory density for each. The effect of site type (i.e. restored vs. reference) in explaining territory density was least for Song Sparrow, greater for Yellow Warbler (for which density was 1.4 times greater on reference sites), and greatest for Yellow-breasted Chat (which were more than twice as dense on reference sites). While territory density and mean territory size were inversely related, we found no relationship between territory density or site type and mean productivity per nest, and nest success did not differ between restored and reference sites for any species. In combination, these results suggest that restoration has achieved short-term success as measured by reproductive success, but has not yet been fully successful in supporting similar territory densities as reference sites. In order to determine whether long-term restoration goals are fully achieved, future research should continue to measure density of the 3 focal species as vegetation on the replanted floodplains matures.","PeriodicalId":50624,"journal":{"name":"Condor","volume":" ","pages":"1 - 12"},"PeriodicalIF":2.4,"publicationDate":"2019-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duz043","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45550399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ospreys: The Revival of a Global Raptor","authors":"I. Macleod","doi":"10.1093/condor/duz045","DOIUrl":"https://doi.org/10.1093/condor/duz045","url":null,"abstract":"","PeriodicalId":50624,"journal":{"name":"Condor","volume":"121 1","pages":"1 - 2"},"PeriodicalIF":2.4,"publicationDate":"2019-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duz045","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44595324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Birds of Maryland, Delaware, and the District of Columbia","authors":"Jean L. Woods","doi":"10.1093/condor/duz046","DOIUrl":"https://doi.org/10.1093/condor/duz046","url":null,"abstract":"","PeriodicalId":50624,"journal":{"name":"Condor","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2019-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duz046","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46855891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Strong population structure and limited gene flow between Yellow-billed Ducks and Mallards in southern Africa","authors":"Joshua I. Brown, Philip Lavretsky, G. Cumming, J. Peters","doi":"10.1093/condor/duz042","DOIUrl":"https://doi.org/10.1093/condor/duz042","url":null,"abstract":"ABSTRACT Secondary contact and hybridization between recently diverged taxa have been increasing due to anthropogenic changes to the environment. Determining whether secondary contact leads to gene flow between species is important for understanding both the evolutionary consequences of such events (i.e. genetic swamping, speciation reversal, hybrid speciation) and for establishing proper conservation measures. Mallards (Anas platyrhynchos), which natively have a Holarctic distribution, have been introduced nearly worldwide due to game-farm and domestic pet releases. Their expanding range has resulted in secondary contact and increased incidences of hybridization with many closely related Mallard-like ducks that comprise the Mallard complex. Here, we assay molecular diversity for 19 nuclear introns and the mitochondrial DNA for wild Mallards (n = 50) across their Holarctic range and Yellow-billed Ducks (n = 30–75; Anas undulata) from southern Africa to determine population genetic structure and test for evidence of Mallard introgression into Yellow-billed Ducks. While we found limited support for contemporary gene flow across nuclear markers, we provide evidence from mitochondrial DNA that best supports ancient gene flow between Yellow-billed Ducks and Mallards. Yellow-billed Ducks best fit a single population at nuclear markers but show some location-specific mtDNA structure that suggests recent founder or bottleneck events. Although we find that introgression from Mallards into Yellow-billed Duck is limited, Yellow-billed Duck populations should be monitored to determine if expanding feral Mallard populations in southern Africa are increasing introgression.","PeriodicalId":50624,"journal":{"name":"Condor","volume":" ","pages":"1 - 10"},"PeriodicalIF":2.4,"publicationDate":"2019-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duz042","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45756163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Proximity to unconventional shale gas infrastructure alters breeding bird abundance and distribution","authors":"L. Farwell, P. Wood, Donald J. Brown, J. Sheehan","doi":"10.1093/condor/duz020","DOIUrl":"https://doi.org/10.1093/condor/duz020","url":null,"abstract":"ABSTRACT Unconventional shale gas development is a rapidly expanding driver of forest loss and fragmentation in the central Appalachian region. We evaluated the relationship between breeding passerine abundances and distance from shale gas development at a long-term (2008–2017) study site in northern West Virginia, USA. We examined responses of 27 species within 3 habitat guilds: forest interior, early successional, and synanthropic. More than half of the species evaluated showed sensitivity to distance from unconventional shale gas infrastructure (e.g., well pads, access roads, pipelines). Five forest interior species occurred in greater abundances farther from shale gas development, whereas 3 forest interior gap specialists increased in abundance closer to shale gas. Early successional and synanthropic species, including the nest-parasitic Brown-headed Cowbird (Molothrus ater), generally occurred in greater abundances closer to shale gas infrastructure. We used interpolated distributions of 4 focal species to assess their spatial response to unconventional shale gas development over time. Our results indicate that breeding passerine distributions and community composition are changing with forest disturbance driven by unconventional shale gas energy development.","PeriodicalId":50624,"journal":{"name":"Condor","volume":" ","pages":"1 - 20"},"PeriodicalIF":2.4,"publicationDate":"2019-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duz020","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46307676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Factors affecting detection probability, effective area surveyed, and species misidentification in grassland bird point counts","authors":"Elizabeth A. Rigby, Douglas H. Johnson","doi":"10.1093/condor/duz030","DOIUrl":"https://doi.org/10.1093/condor/duz030","url":null,"abstract":"ABSTRACT We simulated bird surveys using recorded bird songs to assess factors affecting detection probability in grassland bird point counts. We used mixed effects logistic regression models to estimate effects of those factors and to estimate and visualize the variation in the area around the observer where birds can be perceived (the perception area). We simulated surveys with 8,926 binary opportunities for detection in Minnesota grasslands in 2011 and 2012. Species, distance to the observer, wind speed and direction, observer, and density of vegetation all affected detection of recorded bird songs. Species had a strong effect; the size of the predicted perception area around the observer differed by an order of magnitude among species. Wind also had a strong effect on detection. As wind speed increased, probability of detection downwind of the observer was reduced and the perception area around the observer became smaller and more asymmetrical. The effective distance at which an observer is more likely to detect a bird than not detect it may differ among species and angles to the wind, even within the same survey. Eight of 10 species had low probability of misidentification (≤0.03), but Grasshopper Sparrow (Ammodramus savannarum) and LeConte's Sparrow (Ammospiza leconteii) were frequently misidentified (probability = 0.09–0.24 among observers), contributing to a low rate of correct detection for those species. We recommend collecting point-count data within distance bands so that data can be analyzed based on the effective radius for each species and standardizing surveys across wind conditions to reduce variation in detection probability.","PeriodicalId":50624,"journal":{"name":"Condor","volume":" ","pages":"1 - 10"},"PeriodicalIF":2.4,"publicationDate":"2019-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duz030","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49285082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pasture-scale vegetation predicts Dickcissel nest-site selection and success in native and exotic grass pastures","authors":"A. Monroe, L. Burger, J. Martin","doi":"10.1093/condor/duz027","DOIUrl":"https://doi.org/10.1093/condor/duz027","url":null,"abstract":"ABSTRACT Exotic grasses such as bermudagrass (Cynodon dactylon) and tall fescue (Schedonorus arundinaceus) are widely established across the southeastern United States as livestock forage, but their structure and management can limit avian reproductive success. Native warm-season grasses (NWSG) are promoted as sustainable forage alternatives. To examine nesting suitability for tall structure specialists such as Dickcissels (Spiza americana) we established an operational-scale study in northeastern Mississippi, USA, with 4 treatments along a gradient of beef production intensity. Treatments included grazed exotic forages, 2 grazed NWSG treatments including Indiangrass (Sorghastrum nutans) monoculture and NWSG polyculture of Indiangrass, little bluestem (Schizachyrium scoparium), and big bluestem (Andropogon gerardii), and an ungrazed NWSG polyculture treatment. We monitored 208 Dickcissel nests in 2011 and 2012 to evaluate effects of treatment, vegetation structure, fire ants (Solenopsis spp.), and arthropod prey biomass on nest-site selection and nest survival. Survival rates varied among treatments and increased with pasture-scale visual obstruction reading (VOR), being lowest among grazed exotic grass, intermediate in grazed NWSG, and highest in ungrazed NWSG. Although Dickcissels selected nest sites with greater VOR, we found little support for effects of nest-site vegetation on survival. However, nest survival was lower for nests in shrubs that also occurred in pastures with greater shrub cover, and selection for shrubs declined as pasture-scale VOR increased, suggesting a functional response in selection. We found little support for food availability influencing nest survival. These results suggest NWSG pastures increase Dickcissel nest success through greater pasture-scale VOR by reducing Dickcissel selection of shrubs for nest sites, and possibly by reducing predator efficiency. Incorporating NWSG into beef production systems while maintaining availability of tall vegetation could benefit Dickcissels and other tall structure specialists.","PeriodicalId":50624,"journal":{"name":"Condor","volume":" ","pages":"1 - 14"},"PeriodicalIF":2.4,"publicationDate":"2019-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duz027","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45891114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Archival DNA reveals cryptic biodiversity within the Spotted Shag (Phalacrocorax punctatus) from New Zealand","authors":"Nicolas J. Rawlence, M. Rayner, T. G. Lovegrove, D. Stoddart, M. Vermeulen, L. Easton, A. Tennyson, R. Scofield, M. Kennedy, H. Spencer, J. Waters","doi":"10.1093/condor/duz029","DOIUrl":"https://doi.org/10.1093/condor/duz029","url":null,"abstract":"ABSTRACT Genetic data are increasingly being used to prioritize species conservation in a fiscally constrained age of seemingly boundless conservation crises. Such data can also reveal previously cryptic biodiversity requiring further revision of conservation management guidelines. Using a combination of mitochondrial (control region) and nuclear (beta fibrinogen intron 7) DNA, and morphology, we reveal that the endemic New Zealand Spotted Shag (Phalacrocorax punctatus) complex exhibits phylogenetic structure that is decoupled from previously recorded qualitative morphological variation. Crucially, the most genetically distinct populations within P. punctatus are from northern New Zealand; recent surveys show that these populations, which house important genetic diversity within Spotted Shags, are in danger of being extirpated. In contrast, we find the previously phenotypically differentiated nominate (P. punctatus punctatus) and Blue (P. punctatus oliveri) Shag subspecies show no genetic and morphological separation, and are of least conservation concern.","PeriodicalId":50624,"journal":{"name":"Condor","volume":"121 1","pages":"1 - 16"},"PeriodicalIF":2.4,"publicationDate":"2019-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duz029","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47053556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Urban Ornithology: 150 years of Birds in New York City","authors":"R. Veit","doi":"10.1093/condor/duz041","DOIUrl":"https://doi.org/10.1093/condor/duz041","url":null,"abstract":"","PeriodicalId":50624,"journal":{"name":"Condor","volume":"121 1","pages":"1 - 2 - 514"},"PeriodicalIF":2.4,"publicationDate":"2019-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duz041","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47504471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Barred Owls reduce occupancy and breeding propensity of Northern Spotted Owl in a Washington old-growth forest","authors":"Anna O. Mangan, Tara Chestnut, J. Vogeler, Ian K. Breckheimer, W. M. King, Keith E. Bagnall, Katie M. Dugger","doi":"10.1093/condor/duz031","DOIUrl":"https://doi.org/10.1093/condor/duz031","url":null,"abstract":"ABSTRACT Protected lands like national parks are important refuges for threatened and endangered species as environmental pressures on wildlife and their habitats increase. The Northern Spotted Owl (Strix occidentalis caurina), a species designated as threatened under the Endangered Species Act, occurs on public lands throughout the western United States including Mount Rainier National Park (MRNP), Washington. With virtually no history of timber harvest or large forest disturbance within MRNP boundaries since the park's creation in 1899, MRNP provides an ideal place to evaluate potential impacts of climate change and invasive Barred Owls (Strix varia) on the Northern Spotted Owl. We used a multi-state, multi-season occupancy model to investigate how Northern Spotted Owl occupancy dynamics and breeding propensity are related to the presence of Barred Owls, local and regional weather, and habitat characteristics at MRNP from 1997 to 2016. Historical occupancy of Northern Spotted Owl breeding territories in MRNP has declined by 50% in the last 20 yr, and territory occupancy by breeding Northern Spotted Owls also decreased, reaching a low of 25% in 2016. Occupancy rates were higher on territories with steeper terrain and breeding rates were lower when Barred Owls were detected within historical territories. Our results also indicated that breeding propensity was higher when early nesting season temperatures during March and April were higher. In addition, the ability to detect breeding Northern Spotted Owls decreased when Barred Owls were present in the territory. Habitat variables from LiDAR were not correlated with Northern Spotted Owl occupancy dynamics, likely reflecting the dominance of old-growth forest in this protected park. This study illustrates the strong relationship between Barred Owls and Northern Spotted Owl demographics and breeding site selection in a landscape where habitat loss by timber harvest and fire has not occurred.","PeriodicalId":50624,"journal":{"name":"Condor","volume":"121 1","pages":"1 - 20"},"PeriodicalIF":2.4,"publicationDate":"2019-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duz031","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44083268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}