Condor最新文献

{"title":"Habitat openness and edge avoidance predict Saltmarsh Sparrow abundance better than habitat area","authors":"H. Marshall, Erik J. Blomberg, Valerie K. Watson, M. Conway, J. Cohen, M. Correll, C. Elphick, T. Hodgman, Alison R. Kocek, A. Kovach, W. G. Shriver, Whitney A. Wiest, Brian J. Olsen","doi":"10.1093/condor/duaa019","DOIUrl":"https://doi.org/10.1093/condor/duaa019","url":null,"abstract":"ABSTRACT The Saltmarsh Sparrow (Ammospiza caudacuta) is a tidal marsh bird facing rapid population decline throughout its range, largely caused by degradation and loss of breeding habitat. Thus, there is a need to preserve tidal marshes in the northeastern United States, but to do so requires an understanding of the habitat features that support robust populations. Previous studies have shown Saltmarsh Sparrow abundance increases with marsh size, but in similar bird species, area sensitivity is more directly linked to edge avoidance. Whether additional landscape features affect the abundance of Saltmarsh Sparrows is unknown. We explored how the height of objects on the horizon, an index of habitat openness, affected the abundance of Saltmarsh Sparrows. Our primary goal was to determine whether the angle to the highest point on the horizon (“angle to maximum horizon”) predicted abundance better than marsh area or distance to the marsh edge. We used N-mixture models to evaluate the combination of spatial factors that best predicted Saltmarsh Sparrow abundance while also accounting for survey-level variables that could influence detection probability. We found that the interaction between distance to edge and angle to maximum horizon best predicted abundance. Taller objects on the horizon were negatively correlated with bird abundance, and this effect was strongest within 50 m of the marsh edge. When we considered the predictive powers of patch area, distance to edge, and angle to maximum horizon individually, angle to maximum horizon was the best single predictor. We found the highest abundance of Saltmarsh Sparrows at point locations where the angle to maximum horizon was 0.0°, and at angles greater than 12° the predicted abundance fell below 1 bird per survey point. We propose that managers should prioritize marsh openness and experimentally test the effect of marsh edge manipulations when making conservation decisions for this rapidly declining species.","PeriodicalId":50624,"journal":{"name":"Condor","volume":"122 1","pages":"1 - 13"},"PeriodicalIF":2.4,"publicationDate":"2020-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duaa019","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42458716","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":"Lessons learned from comparing spatially explicit models and the Partners in Flight approach to estimate population sizes of boreal birds in Alberta, Canada","authors":"P. Sólymos, J. Toms, Steven M. Matsuoka, S. Cumming, Nicole Barker, W. Thogmartin, D. Stralberg, A. Crosby, Francisco V. Dénes, S. Haché, C. L. Mahon, F. Schmiegelow, E. Bayne","doi":"10.1093/condor/duaa007","DOIUrl":"https://doi.org/10.1093/condor/duaa007","url":null,"abstract":"ABSTRACT Estimating the population abundance of landbirds is a challenging task complicated by the amount, type, and quality of available data. Avian conservationists have relied on population estimates from Partners in Flight (PIF), which primarily uses roadside data from the North American Breeding Bird Survey (BBS). However, the BBS was not designed to estimate population sizes. Therefore, we set out to compare the PIF approach with spatially explicit models incorporating roadside and off-road point-count surveys. We calculated population estimates for 81 landbird species in Bird Conservation Region 6 in Alberta, Canada, using land cover and climate as predictors. We also developed a framework to evaluate how the differences between the detection distance, time-of-day, roadside count, and habitat representation adjustments explain discrepancies between the 2 estimators. We showed that the key assumptions of the PIF population estimator were commonly violated in this region, and that the 2 approaches provided different population estimates for most species. The average differences between estimators were explained by differences in the detection-distance and time-of-day components, but these adjustments left much unexplained variation among species. Differences in the roadside count and habitat representation components explained most of the among-species variation. The variation caused by these factors was large enough to change the population ranking of the species. The roadside count bias needs serious attention when roadside surveys are used to extrapolate over off-road areas. Habitat representation bias is likely prevalent in regions sparsely and non-representatively sampled by roadside surveys, such as the boreal region of North America, and thus population estimates for these regions need to be treated with caution for certain species. Additional sampling and integrated modeling of available data sources can contribute towards more accurate population estimates for conservation in remote areas of North America.","PeriodicalId":50624,"journal":{"name":"Condor","volume":"122 1","pages":"1 - 22"},"PeriodicalIF":2.4,"publicationDate":"2020-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duaa007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43294185","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 suppress pests in corn but release them in soybean crops within a mixed prairie/agriculture system.","authors":"Megan B Garfinkel, Emily S Minor, Christopher J Whelan","doi":"10.1093/condor/duaa009","DOIUrl":"10.1093/condor/duaa009","url":null,"abstract":"<p><p>Birds provide ecosystem services (pest control) in many agroecosystems and have neutral or negative ecological effects (disservices) in others. Large-scale, conventional row crop agriculture is extremely widespread globally, yet few studies of bird effects take place in these agroecosystems. We studied indirect effects of insectivorous birds on corn and soybean crops in fields adjacent to a prairie in Illinois (USA). We hypothesized that prairie birds would forage for arthropods in adjacent crop fields and that the magnitude of services or disservices would decrease with distance from the prairie. We used bird-excluding cages over crops to examine the net effect of birds on corn and soybean grain yield. We also conducted DNA metabarcoding to identify arthropod prey in fecal samples from captured birds. Our exclosure experiments revealed that birds provided net services in corn and net disservices in soybeans. Distance from prairie was not a significant predictor of exclosure treatment effect in either crop. Many bird fecal samples contained DNA from both beneficial arthropods and known economically significant pests of corn, but few economically significant pests of soybeans. Song Sparrows (<i>Melospiza melodia</i>), one of our most captured species, most commonly consumed corn rootworms, an economically significant pest of corn crops. We estimated that birds in this system provided a service worth approximately US $275 ha^-1 in corn yield gain, and a disservice valued at approximately $348 ha^-1 in soybean yield loss. Our study is the first to demonstrate that birds can provide substantial and economically valuable services in field corn, and disservices in soybean crops. The contrasting findings in the 2 crop systems suggest a range of bird impacts within widespread agroecosystems and demonstrate the importance of quantifying net trophic effects.</p>","PeriodicalId":50624,"journal":{"name":"Condor","volume":"122 2","pages":"duaa009"},"PeriodicalIF":2.4,"publicationDate":"2020-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7243448/pdf/duaa009.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37994622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Applying conservation social science to study the human dimensions of Neotropical bird conservation","authors":"A. Dayer, Eduardo A. Silva‐Rodríguez, S. Albert, M. Chapman, Benjamin Zukowski, J. Ibarra, Gemara Gifford, A. Echeverri, A. Martínez-Salinas, Claudia Sepúlveda-Luque","doi":"10.1093/condor/duaa021","DOIUrl":"https://doi.org/10.1093/condor/duaa021","url":null,"abstract":"ABSTRACT As the global human population increases, and many bird populations in the Neotropics and the rest of the world continue to decline, the study of the intersection of humans, birds, and conservation has become more relevant than ever. The field of conservation social science is an interdisciplinary field that applies the social sciences and humanities to examine research questions that have implications for biodiversity conservation, and encompasses disciplines as diverse as psychology, economics, and political ecology. An understanding of the human dimensions of biodiversity conservation issues can be an essential element in the success or failure of a conservation initiative, policy, or practice. The purpose of this article is to provide an understanding of the growing body of conservation social science relevant to Neotropical bird conservation research and to demonstrate its importance. We discuss how this research can contribute to addressing 5 major threats to bird conservation in the Neotropics, including future research needs, and we provide 3 case studies of bird conservation social science projects, demonstrating the insights that can be gained. We close with a discussion of how conservation biologists and ornithologists can most effectively work with conservation social scientists.","PeriodicalId":50624,"journal":{"name":"Condor","volume":" ","pages":"1 - 15"},"PeriodicalIF":2.4,"publicationDate":"2020-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duaa021","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44156624","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":"Passive acoustic monitoring effectively detects Northern Spotted Owls and Barred Owls over a range of forest conditions","authors":"Leila S. Duchac, D. B. Lesmeister, Katie M. Dugger, Zachary J. Ruff, Raymond J. Davis","doi":"10.1093/condor/duaa017","DOIUrl":"https://doi.org/10.1093/condor/duaa017","url":null,"abstract":"\u0000 Passive acoustic monitoring using autonomous recording units (ARUs) is a fast-growing area of wildlife research especially for rare, cryptic species that vocalize. Northern Spotted Owl (Strix occidentalis caurina) populations have been monitored since the mid-1980s using mark–recapture methods. To evaluate an alternative survey method, we used ARUs to detect calls of Northern Spotted Owls and Barred Owls (S. varia), a congener that has expanded its range into the Pacific Northwest and threatens Northern Spotted Owl persistence. We set ARUs at 30 500-ha hexagons (150 ARU stations) with recent Northern Spotted Owl activity and high Barred Owl density within Northern Spotted Owl demographic study areas in Oregon and Washington, and set ARUs to record continuously each night from March to July, 2017. We reviewed spectrograms (visual representations of sound) and tagged target vocalizations to extract calls from ~160,000 hr of recordings. Even in a study area with low occupancy rates on historical territories (Washington’s Olympic Peninsula), the probability of detecting a Northern Spotted Owl when it was present in a hexagon exceeded 0.95 after 3 weeks of recording. Environmental noise, mainly from rain, wind, and streams, decreased detection probabilities for both species over all study areas. Using demographic information about known Northern Spotted Owls, we found that weekly detection probabilities of Northern Spotted Owls were higher when ARUs were closer to known nests and activity centers and when owls were paired, suggesting passive acoustic data alone could help locate Northern Spotted Owl pairs on the landscape. These results demonstrate that ARUs can effectively detect Northern Spotted Owls when they are present, even in a landscape with high Barred Owl density, thereby facilitating the use of passive, occupancy-based study designs to monitor Northern Spotted Owl populations.","PeriodicalId":50624,"journal":{"name":"Condor","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2020-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duaa017","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46809494","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":"Corrigendum: Testing a key assumption of using drones as frightening devices: Do birds perceive drones as risky?","authors":"Conor C. Egan, B. F. Blackwell, E. Fernández‐Juricic, Page E. Klug","doi":"10.1093/condor/duaa025","DOIUrl":"https://doi.org/10.1093/condor/duaa025","url":null,"abstract":"","PeriodicalId":50624,"journal":{"name":"Condor","volume":"122 1","pages":"1 - 1"},"PeriodicalIF":2.4,"publicationDate":"2020-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duaa025","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45735089","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":"Broad-spectrum light pollution suppresses melatonin and increases West Nile virus–induced mortality in House Sparrows (Passer domesticus)","authors":"Meredith E. Kernbach, V. Cassone, T. Unnasch, Lynn B. Martin","doi":"10.1093/condor/duaa018","DOIUrl":"https://doi.org/10.1093/condor/duaa018","url":null,"abstract":"ABSTRACT Artificial light at night (ALAN) has become a pervasive anthropogenic stressor for both humans and wildlife. Although many negative impacts of ALAN on human health have been identified, the consequences for infectious disease dynamics are largely unexplored. With the increase in popularity of energy efficient light-emitting diodes (LEDs), the effects of spectral composition of ALAN have also come into question. Previous studies showed that exposure to low levels of incandescent ALAN extended the infectious period of House Sparrows (Passer domesticus) infected with West Nile virus (WNV) without affecting mortality rates, thus increasing the pathogen initial reproductive rate (R0) by ∼41%. Here, we asked whether exposure to broad-spectrum (3000 K [Kelvin; unit of color temperature]) ALAN suppressed melatonin, a hormone implicated in ALAN-induced physiological consequences, in House Sparrows. We then asked whether amber-hue bulbs (1800 K) could ameliorate the effects of WNV on individual sparrows, and whether broad-spectrum or blue-rich bulbs (3000 K and 5000 K, respectively) could exacerbate them. We found that exposure to low intensity (∼5 lux) broad-spectrum (3000 K) ALAN significantly suppressed melatonin levels throughout the night. Second, we found that exposure to broad-spectrum and blue-rich (3000 + 5000 K) lights did not affect WNV viremia but did increase WNV-induced mortality. Conversely, birds exposed to amber-hue (1800 K) ALAN had lower viremia and mortality rates similar to controls (i.e. natural light conditions). This study demonstrates that ALAN affects melatonin regulation in birds, but this effect, as well as ALAN influences on infectious disease responses, can be ameliorated by particular lighting technologies.","PeriodicalId":50624,"journal":{"name":"Condor","volume":" ","pages":"1 - 13"},"PeriodicalIF":2.4,"publicationDate":"2020-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duaa018","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45945379","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":"Living in a fragmented world: Birds in the Atlantic Forest","authors":"M. A. Pizo, V. Tonetti","doi":"10.1093/condor/duaa023","DOIUrl":"https://doi.org/10.1093/condor/duaa023","url":null,"abstract":"ABSTRACT The Atlantic Forest is the second largest tropical moist forest domain in South America after the Amazon, home to over 800 bird species (223 endemics or 27% of the avifauna). With only 28% of the original vegetation left, mostly fragmented and altered, the Atlantic Forest is a hotspot for bird conservation. We first introduce the extent, vegetation types, and exploitation history of the domain, and the composition and biogeographic affinities of its birds. We then provide an overview of the knowledge gathered so far on the ways Atlantic Forest birds thrive in the often-fragmented landscape, highlighting the landscape features that influence their occurrence and movement behavior. We end with the conservation issues affecting the Atlantic Forest birds and the actions hitherto taken to address them, including the establishment of conservation units, forest restoration, and rewilding.","PeriodicalId":50624,"journal":{"name":"Condor","volume":" ","pages":"1 - 14"},"PeriodicalIF":2.4,"publicationDate":"2020-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duaa023","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47491275","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":"Creating benchmark measurements of tropical forest bird communities in large plots","authors":"W. Robinson, J. Curtis","doi":"10.1093/condor/duaa015","DOIUrl":"https://doi.org/10.1093/condor/duaa015","url":null,"abstract":"ABSTRACT An understanding of how tropical bird communities might respond to climate change and other types of environmental stressors seems particularly urgent, yet we still lack, except for a few sites, even snapshot inventories of avian richness and abundances across most of the tropics. Such benchmark measurements of tropical bird species richness and abundances could provide opportunities for future repeat surveys and, therefore, strong insight into degrees and pace of change in community organization over time. The challenges of creating a network of benchmarked sites include high variation in detectability among species, general rarity of many species that creates hurdles for use of modern bird counting methods aimed at controlling for variation in detectability, and lack of a standardized protocol to create repeatable inventories. We argue that reasonably complete inventories of tropical bird communities require use of multiple survey techniques to provide internal calibrations of abundance estimates and require multiple visits to improve completeness of richness inventories. We suggest that a network of large (50–100 ha) plots scattered across the tropics can also provide insights into geographic variation in and drivers of avian community structure analogous to insights provided by the Smithsonian Center for Tropical Forest Science Forest Global Earth Observatory network of forest dynamics plots. Perhaps most importantly, large plots provide opportunities for use of multiple survey techniques to estimate abundances while also using some exactly repeatable survey techniques that can greatly improve abilities to quantify change over time. We provide guidance on establishment of and survey methods for large tropical bird plots as well as important recommendations for collection and archiving of metadata to safeguard the long-term utility of valuable benchmark data.","PeriodicalId":50624,"journal":{"name":"Condor","volume":"122 1","pages":"1 - 15"},"PeriodicalIF":2.4,"publicationDate":"2020-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duaa015","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41328674","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":"Ecosystem services provided by Neotropical birds","authors":"N. Michel, C. Whelan, Gregory M. Verutes","doi":"10.1093/condor/duaa022","DOIUrl":"https://doi.org/10.1093/condor/duaa022","url":null,"abstract":"ABSTRACT The Millennium Ecosystem Assessment described 4 classes of services or functions that ecosystems and their component parts deliver to the benefit of humans: provisioning, regulating, supporting, and cultural services. Birds, including Neotropical birds, provide a diverse array of services in all 4 classes. We review the literature describing ecosystem services provided by Neotropical birds, draw inference from studies of avian services in other regions when Neotropical studies are limited, and identify key information gaps. Neotropical birds provide provisioning services in the form of meat and eggs for food, and feathers for down and ornamentation. Regulating services are among the most valuable services provided by Neotropical birds, including pollination, pest control, seed dispersal, and scavenging. Neotropical birds also provide supporting services in the form of nutrient cycling, such as through the deposition of guano on offshore islands. Finally, Neotropical birds provide cultural services as pets (caged birds), sources of recreation (e.g., birdwatching, hunting), as well as by inspiring art, photography, and religious customs. Much remains to be learned about the ecology and natural history of many Neotropical birds before we can fully assign value—monetary, nonmaterial, or otherwise—to the services they provide. However, what we have learned to date makes it clear that humans benefit from birds through multiple services, including but not limited to pest reduction, pollination of some agricultural plants, and seed dispersal.","PeriodicalId":50624,"journal":{"name":"Condor","volume":"122 1","pages":"1 - 21"},"PeriodicalIF":2.4,"publicationDate":"2020-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duaa022","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43903247","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}