Condor最新文献

{"title":"Shorebird subsistence harvest and indigenous knowledge in Alaska: Informing harvest management and engaging users in shorebird conservation","authors":"Liliana C. Naves, Jacqueline M. Keating, T. Tibbitts, D. Ruthrauff","doi":"10.1093/condor/duz023","DOIUrl":"https://doi.org/10.1093/condor/duz023","url":null,"abstract":"ABSTRACT Limited data on harvest and population parameters are impediments to assessing shorebird harvest sustainability. Because of sharp declines in shorebird populations, timely conservation efforts require approaches that account for uncertainty in harvest sustainability. We combined harvest assessment and ethnographic research to better understand shorebird conservation concerns related to subsistence harvest in Alaska and to support culturally sensible conservation actions. Our objectives were to (1) estimate the Alaska-wide shorebird subsistence harvest and (2) document shorebird indigenous knowledge on the Yukon-Kuskokwim Delta. Harvest estimates were based on surveys conducted in 1990–2015 (n = 775 community-years). Key respondent interviews conducted in 2017 (n = 72) documented shorebird ethnotaxonomy and ethnography. The Alaska-wide shorebird harvest was 2,783 birds per year, including 1,115 godwits per year—mostly Bar-tailed Godwits (Limosa lapponica baueri), whose population has low harvest potential. The egg harvest was 4,678 eggs per year, mostly small shorebird eggs. We documented 24 Yup'ik shorebird names and 10 main ethnotaxonomic categories. Children learning harvesting skills focused on small birds and adults also occasionally harvested shorebirds, but shorebirds were not primary food or cultural resources. Older generations associated shorebirds with a time when people were closer to nature and their cultural roots. Shorebirds connected people with the environment as well as with Yup'ik traditions and language. Our results can inform improvements to harvest assessment and management, as well as outreach and communication efforts to engage subsistence users in shorebird conservation.","PeriodicalId":50624,"journal":{"name":"Condor","volume":"121 1","pages":"1 - 19"},"PeriodicalIF":2.4,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duz023","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60894022","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":"Threatened habitat at Great Salt Lake: Importance of shallow-water and brackish habitats to Wilson's and Red-necked phalaropes","authors":"Maureen G. Frank, M. Conover","doi":"10.1093/condor/duz005","DOIUrl":"https://doi.org/10.1093/condor/duz005","url":null,"abstract":"ABSTRACT Great Salt Lake (GSL) is the largest hypersaline lake in North America and is the fall staging area for a high proportion of North America's Wilson's Phalaropes (Phalaropus tricolor) and Red-necked Phalaropes (Phalaropus lobatus). Unfortunately, diversion of freshwater for agriculture and development has decreased the size of GSL by 48%. To assess the potential impact of a smaller GSL on phalaropes, we collected data from 2013 to 2015 from sites where large, dense flocks of phalaropes congregated and sites where there were no phalaropes. At each site, we measured the densities of invertebrates that were preyed upon by phalaropes, including larval and adult brine flies (Ephydridae), adult brine shrimp (Artemia franciscana), chironomid larvae (Chironomidae), and corixid adults (Corixidae). Abiotic characteristics measured included water depth, water salinity, water temperature, wind speed, and benthic substrate. We analyzed high-salinity sites separately from low-salinity sites because they contained different invertebrates. High-salinity sites were in Carrington and Gilbert bays and were relatively deep (mostly <2 m). At the high-salinity sites, phalaropes exhibited a preference for sites with an abundance of adult brine flies and for microbialite substrates. The low-salinity sites were in Ogden and Farmington bays and were shallow (<1 m). At low-salinity sites, large phalarope flocks were more likely to occur at sites that were shallower, less saline, and had a high biomass of benthic macroinvertebrates. Our results indicate that physical features and prey availability are both important in determining phalarope habitat use at GSL. Phalaropes prefer to use shallower parts of GSL and brackish waters. These areas will be especially impacted by decreased freshwater inflow into GSL.","PeriodicalId":50624,"journal":{"name":"Condor","volume":" ","pages":"1 - 13"},"PeriodicalIF":2.4,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duz005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43826209","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":"No evidence of a demographic response to experimental herbicide treatments by the White-crowned Sparrow, an early successional forest songbird","authors":"J. Rivers, Jake Verschuyl, C. Schwarz, A. J. Kroll, M. Betts","doi":"10.1093/condor/duz004","DOIUrl":"https://doi.org/10.1093/condor/duz004","url":null,"abstract":"ABSTRACT Early-successional forest birds, which depend on disturbance events within forested landscapes, have received increased conservation concern because of long-term population declines. Herbicides are often used to control vegetation within early-successional forests, with unknown effects on avian vital rates. We used a large–scale experiment to test how nest and post–fledging survival were influenced by herbicide intensity within managed conifer plantations across 2 breeding seasons. We created a gradient of 4 stand–scale herbicide treatments (light, moderate, and intensive, and no–spray control) and evaluated the reproductive response of the White–crowned Sparrow (Zonotrichia leucophrys), a declining songbird in managed forest landscapes of the Pacific Northwest. Against initial predictions, we found no evidence that either daily nest survival (n > 760 nests across all treatments) or post–fledging survival (n = 70 individuals reared in control and moderate treatments) were influenced by herbicide application intensity. Increased herbicide intensity resulted in an extensive reduction in vegetation cover at both stand and nest–patch scales; in contrast, vegetative cover at nest sites did not differ across herbicide treatments, nor was nest survival related to vegetation concealment measures. As the largest experimental investigation to assess forest herbicide effects on songbird demography, our study indicates that components of sparrow reproductive success were not influenced by experimental vegetation control measures, although additional work on other early-successional species will be useful to evaluate the generalities of our findings.","PeriodicalId":50624,"journal":{"name":"Condor","volume":" ","pages":"1 - 13"},"PeriodicalIF":2.4,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duz004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42861911","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":"Cumulative impacts of roads and energy infrastructure on grassland songbirds","authors":"J. Daniel, N. Koper","doi":"10.1093/condor/duz011","DOIUrl":"https://doi.org/10.1093/condor/duz011","url":null,"abstract":"ABSTRACT Comparing impacts of co-occurring anthropogenic features is necessary for regional planning and can help identify mechanisms of negative impacts of development on wildlife. Because of the vast abundance of anthropogenic features in the Northern Great Plains, their combined negative impacts on songbird habitat use (e.g., abundance) and productivity (e.g., nesting success and clutch size) could exacerbate the decline of songbird populations. We compared the cumulative effects of energy-related infrastructure (oil wells, shallow gas wells, and roads) on habitat use and productivity of songbirds across a 120 × 180 km region in southern Alberta, Canada. We examined effects on Chestnut-collared Longspur (Calcarius ornatus) and Sprague's Pipit (Anthus spragueii), both of which are listed as Threatened in Canada, and Savannah Sparrow (Passerculus sandwichensis), Vesper Sparrow (Pooecetes gramineus), and Western Meadowlark (Sturnella neglecta). Using piecewise regressions and generalized linear models, we estimated effects of distance from infrastructure and shallow gas well density on the habitat use and productivity of each species. We then used these analyses to quantify the availability of habitat suitable for settlement and breeding throughout our study region. Shallow gas wells, which are more abundant, affected a larger geographic area than oil wells, but oil wells were associated with the added impacts of roads. Our analyses suggest that impacts of wells on songbirds are not caused by industrial noise because individual shallow gas wells, which produce no mechanical noise, had similar impacts to noisy oil wells. Our results highlight the importance of regional plans that consider the impacts of multiple co-occurring anthropogenic features in working landscapes.","PeriodicalId":50624,"journal":{"name":"Condor","volume":"121 1","pages":"1 - 21"},"PeriodicalIF":2.4,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duz011","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48508678","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":"Conservation implications of extraordinary Greater Scaup (Aythya marila) concentrations in the Odra Estuary, Poland","authors":"D. Marchowski, M. Leitner","doi":"10.1093/condor/duz013","DOIUrl":"https://doi.org/10.1093/condor/duz013","url":null,"abstract":"ABSTRACT Human activities in marine coastal areas may coincide with protected areas for birds. Some of these anthropogenic activities may pose threats, such as gillnet fisheries, which can significantly affect populations of diving birds, especially gregarious species that gather in huge flocks in small areas such as Greater Scaup (Aythya marila). The Odra Estuary (Baltic Sea, Poland) is known for its importance as a wintering site for scaup; it is also used by fishermen using gillnets. Precise tools to determine the distribution and abundance of birds allow evaluation of risks faced by large aggregations. We used kernel density interpolation to estimate the spatial density of scaup in the Odra Estuary in spring 2011. At that time, an extraordinarily high number of scaup (95,400) was recorded, ∼73% (63.0–94.5%) of the entire northwest European flyway population. Three variables are particularly important for conserving highly mobile long-distance migrating species: spatial distribution, abundance, and time (season of the year). This event concentrated most of the scaup flyway population in a small space, making the population vulnerable to mass mortality. We also show aggregated data of the spatial distribution of scaup during the 2015–2016 and 2016–2017 seasons to highlight differences in the spatial use of the area between seasons. Vast areas occupied by scaup in 2011 were not used during 2 other studied seasons; this spatial variation may be crucial in conservation planning of this species. Our results are a first step in documenting the spatial distribution of scaup in the Odra Estuary and identifying the potential area of overlap with fishing activity.","PeriodicalId":50624,"journal":{"name":"Condor","volume":" ","pages":"1 - 10"},"PeriodicalIF":2.4,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duz013","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49114129","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":"Concentration of a widespread breeding population in a few critically important nonbreeding areas: Migratory connectivity in the Prothonotary Warbler","authors":"C. Tonra, M. Hallworth, T. Boves, Jessie Reese, L. Bulluck, Matthew S. Johnson, C. Viverette, Katie L. Percy, Elizabeth M. Ames, Alix E. Matthews, Morgan C. Slevin, R Randy Wilson, Erik I Johnson","doi":"10.1093/condor/duz019","DOIUrl":"https://doi.org/10.1093/condor/duz019","url":null,"abstract":"ABSTRACT One of the greatest challenges to informed conservation of migratory animals is elucidating spatiotemporal variation in distributions. Without such information, it is impossible to understand full-annual-cycle ecology and effectively implement conservation actions that address where and when populations are most limited. We deployed and recovered light-level geolocators (n = 34) at 6 breeding sites in North America across the breeding range of a declining long-distance migratory bird, the Prothonotary Warbler (Protonotaria citrea). We sought to determine migratory routes, stopover location and duration, and the location of overwintering grounds. We found that the species exhibits a large-scale, east—west split in migratory routes and weak migratory connectivity across its range. Specifically, almost all individuals, regardless of breeding origin, overlapped in their estimated wintering location in northern Colombia, in an area 20% the size of the breeding range. Additionally, most of the individuals across all breeding locations concentrated in well-defined stopover locations in Central America while en route to Colombia. Although error inherent in light-level geolocation cannot be fully ruled out, surprisingly much of the estimated wintering area included inland areas even though the Prothonotary Warbler is considered a specialist on coastal mangroves in winter. Based on these results, conservation efforts directed at very specific nonbreeding geographical areas will potentially have benefits across most of the breeding population. Our findings highlight the importance of using modern technologies to validate assumptions about little-studied portions of a species' annual cycle, and the need to distribute sampling across its range.","PeriodicalId":50624,"journal":{"name":"Condor","volume":" ","pages":"1 - 15"},"PeriodicalIF":2.4,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duz019","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49623623","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":"Reconstructing Greater Sage-Grouse chick diets: Diet selection, body condition, and food availability at brood-rearing sites","authors":"Kurt T. Smith, Aaron C. Pratt, Jason R. Levan, Ashleigh M. Rhea, Jeffrey L. Beck","doi":"10.1093/condor/duy012","DOIUrl":"https://doi.org/10.1093/condor/duy012","url":null,"abstract":"ABSTRACT Growth and survival of juvenile birds is nutritionally demanding, making the availability of major foods critical to population productivity. Access to nutritious foods for juveniles has important implications because poor foraging conditions during development could result in mortality, or reduced fitness in adulthood. Selection of brood-rearing habitats by female Greater Sage-Grouse (Centrocercus urophasianus) thus has broad implications to survival of juveniles and persistence of populations. Previous research using crop contents demonstrated that invertebrates and forbs comprise the major portion of sage-grouse chick diets for the first few months post-hatch. We coupled stable isotope analysis of feathers and field measurements to quantify chick diet and then correlated that with measures of chick body condition. We sought to reconstruct sage-grouse chick dietary history (2013–2015) using nitrogen stable isotopes to (1) evaluate whether selection of brood-rearing habitats by female sage-grouse was related to chick diet, and (2) assess the relationship between dietary consumption and body condition. Brood-rearing females selected habitats in areas where diet resources occurred in proportion to their availability, with the exception that females selected areas with greater forb abundance 4 weeks after hatch. Diet assimilation by chicks at brood-rearing locations was unrelated to the availability of forbs and invertebrates, but consumption of forbs increased with chick age. Chicks that assimilated proportionally greater amounts of plant-derived nitrogen in their feathers during their first week of life tended to weigh more and have longer wing chords. This relationship was similar between male and female chicks. The importance of quality foods for sage-grouse is well recognized and conservation efforts should aim to maintain functioning sagebrush ecosystems containing adequate brood-rearing habitats for juvenile sage-grouse; there remains a need to identify whether desirable effects are achievable when attempting to improve big sagebrush (Artemisia tridentata) habitats to benefit sage-grouse populations.","PeriodicalId":50624,"journal":{"name":"Condor","volume":"121 1","pages":"1 - 12"},"PeriodicalIF":2.4,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duy012","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44518270","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":"The Birds at My Table: Why We Feed Wild Birds and Why it Matters","authors":"D. J. Horn","doi":"10.1093/CONDOR/DUY011","DOIUrl":"https://doi.org/10.1093/CONDOR/DUY011","url":null,"abstract":"","PeriodicalId":50624,"journal":{"name":"Condor","volume":"121 1","pages":"1 - 2 - 327"},"PeriodicalIF":2.4,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/CONDOR/DUY011","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44133144","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":"The importance of disturbance and forest structure to bird abundance in the Black Hills","authors":"Elizabeth A. Matseur, J. Millspaugh, F. Thompson, B. Dickerson, M. A. Rumble","doi":"10.1093/condor/duy023","DOIUrl":"https://doi.org/10.1093/condor/duy023","url":null,"abstract":"ABSTRACT Many North American birds associated with forest disturbances such as wildfire and mountain pine beetle (Dendroctonus ponderosae) outbreaks are declining in abundance. More information on relationships between avian abundance and forest structure and disturbance is needed to guide conservation and management. Our objective was to determine densities of American Three-toed Woodpecker (Picoides dorsalis), Black-backed Woodpecker (Picoides arcticus), Red-breasted Nuthatch (Sitta canadensis), Brown Creeper (Certhia americana), and White-winged Junco (Junco hyemalis aikeni) in relation to vegetation characteristics and disturbance at the point and landscape level in the Black Hills and Bear Lodge Mountains of South Dakota and Wyoming. We conducted 3 point counts from late March to late June 2015 and 2016 at more than 2,300 locations distributed across a gradient of forest structure and disturbance types. We estimated densities using 3-level hierarchical time-removal models that simultaneously estimated abundance, availability, and detection probability. Black-backed Woodpeckers were positively related to percent area in 1- to 3-year-old wildfires and Brown Creepers were positively associated with percent area in 4- to 5-year-old wildfires; however, Red-breasted Nuthatches were negatively related to percent area in 3- to 5-year-old wildfires. With the exception of American Three-toed Woodpeckers, species were positively related to percent cover of beetle-killed trees. Brown Creepers, White-winged Juncos, and Red-breasted Nuthatches had mixed responses to percent overstory canopy cover. White-winged Juncos also had a positive association with percent ground vegetation at the point and landscape level. Brown Creepers were strongly linked with spruce vegetation type. American Three-toed Woodpeckers, which are thought to occupy spruce forest in the Black Hills, did not show a strong relationship with any covariates. Maintaining some areas of natural disturbances along with heterogeneity of vegetation characteristics within stands and at the landscape scale will benefit the needs of a diverse bird community in the Black Hills.","PeriodicalId":50624,"journal":{"name":"Condor","volume":"121 1","pages":"1 - 18"},"PeriodicalIF":2.4,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duy023","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43110240","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":"Thinning alters avian occupancy in piñon–juniper woodlands","authors":"P. A. Magee, J. Coop, Jacob S. Ivan","doi":"10.1093/condor/duy008","DOIUrl":"https://doi.org/10.1093/condor/duy008","url":null,"abstract":"ABSTRACT Natural resource managers are increasingly applying tree reduction treatments to piñon–juniper woodlands to meet a range of ecological, social, and economic goals. However, treatment effects on woodland-obligate bird species are not well understood. We measured multiscale avian occupancy on 29 paired (control/treatment) sites in piñon–juniper woodlands in central Colorado, USA. We conducted point counts at 232 stations, 3 times each season in 2014 and 2015. We used hierarchical multiscale modeling to obtain unbiased estimates of landscape and local occupancy (i.e. probability of use) in treated and untreated sites for 31 species. Treatments reduced the occupancy of conifer obligates, including Mountain Chickadee (Poecile gambeli), Clark's Nutcracker (Nucifraga columbiana), and White-breasted Nuthatch (Sitta carolinensis), and increased occupancy of Lark Sparrow (Chondestes grammacus) and Mountain Bluebird (Sialia currucoides). Occupancy of Virginia's Warbler (Oreothylpis virginiae) and Gray Flycatcher (Empidonax wrightii), two piñon–juniper specialists, decreased at the landscape scale in treated sites, and Pinyon Jay (Gymnorhinus cyanocephalus) occupancy decreased at the local scale. Tree reduction treatments in piñon–juniper woodlands have the potential to reduce habitat quality for a suite of bird species of conservation concern. We suggest that treatments designed to retain higher tree density and basal area will benefit conifer-obligate and piñon–juniper specialist bird species.","PeriodicalId":50624,"journal":{"name":"Condor","volume":"121 1","pages":"1 - 17"},"PeriodicalIF":2.4,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duy008","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48102239","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}