Pub Date : 2024-01-16DOI: 10.1093/ornithapp/duad063
J. H. Gammonley
{"title":"Duck Walk: A Birder’s Improbable Path to Hunting as Conservation","authors":"J. H. Gammonley","doi":"10.1093/ornithapp/duad063","DOIUrl":"https://doi.org/10.1093/ornithapp/duad063","url":null,"abstract":"","PeriodicalId":125764,"journal":{"name":"Ornithological Applications","volume":" 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139619209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-11DOI: 10.1093/ornithapp/duae001
Alexander C. Rischette, B. Geaumont, Cameron A. Duquette, T. Hovick
Upland Sandpipers (Bartramia longicauda) are a grassland obligate shorebird that nests in dense vegetation structure near recently disturbed areas and could benefit from management practices that promote heterogenous vegetation structure. Upland Sandpipers primary breeding range is generally managed for livestock production using traditional practices that lack patchy disturbances to facilitate higher levels of structural heterogeneity. Patch-burn grazing (PBG) could be an alternative management practice for Upland Sandpiper conservation for its use to create areas of dense vegetation structure near recently disturbed areas. However, limited information is available regarding nest production of Upland Sandpipers within a PBG framework. To assess the compatibility of PBG with Upland Sandpiper conservation, we estimated nest site selection and survival of Upland Sandpiper nests on private lands managed with PBG in the unglaciated plains region of North Dakota. We located 59 nests from 2017 to 2020. Upland Sandpipers avoided 1 year since fire (YSF) patches and selected for 2 and 3 YSF patches for nest sites. Additionally, nest site selection decreased with increased bare ground and at intermediate distances to the nearest Upland Sandpiper nest. Upland Sandpipers experienced high overall nest survival during the study with 51 of 59 nests successfully hatching, which limited our ability to make inferences between daily survival rates and variables of interest. Our findings suggest that PBG can provide suitable nesting cover for Upland Sandpipers in later YSF patches despite annual prescribed fire and livestock grazing during the nesting season. PBG seems a suitable grassland management strategy that should be included in conservation planning within Upland Sandpiper’s breeding distribution.
{"title":"Upland Sandpipers select for later time since fire and experience high nest survival in grasslands managed with patch-burn grazing","authors":"Alexander C. Rischette, B. Geaumont, Cameron A. Duquette, T. Hovick","doi":"10.1093/ornithapp/duae001","DOIUrl":"https://doi.org/10.1093/ornithapp/duae001","url":null,"abstract":"\u0000 Upland Sandpipers (Bartramia longicauda) are a grassland obligate shorebird that nests in dense vegetation structure near recently disturbed areas and could benefit from management practices that promote heterogenous vegetation structure. Upland Sandpipers primary breeding range is generally managed for livestock production using traditional practices that lack patchy disturbances to facilitate higher levels of structural heterogeneity. Patch-burn grazing (PBG) could be an alternative management practice for Upland Sandpiper conservation for its use to create areas of dense vegetation structure near recently disturbed areas. However, limited information is available regarding nest production of Upland Sandpipers within a PBG framework. To assess the compatibility of PBG with Upland Sandpiper conservation, we estimated nest site selection and survival of Upland Sandpiper nests on private lands managed with PBG in the unglaciated plains region of North Dakota. We located 59 nests from 2017 to 2020. Upland Sandpipers avoided 1 year since fire (YSF) patches and selected for 2 and 3 YSF patches for nest sites. Additionally, nest site selection decreased with increased bare ground and at intermediate distances to the nearest Upland Sandpiper nest. Upland Sandpipers experienced high overall nest survival during the study with 51 of 59 nests successfully hatching, which limited our ability to make inferences between daily survival rates and variables of interest. Our findings suggest that PBG can provide suitable nesting cover for Upland Sandpipers in later YSF patches despite annual prescribed fire and livestock grazing during the nesting season. PBG seems a suitable grassland management strategy that should be included in conservation planning within Upland Sandpiper’s breeding distribution.","PeriodicalId":125764,"journal":{"name":"Ornithological Applications","volume":"6 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139438455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-22DOI: 10.1093/ornithapp/duad066
James E. Lyons, Stephen C Brown, S. Saalfeld, James A Johnson, B. Andres, Kristine M. Sowl, Robert E Gill, B. Mccaffery, Lindall R. Kidd, Metta McGarvey, Brad Winn, H. Gates, D. Granfors, R. Lanctot
Baseline information about declining North American shorebird populations is essential to determine the effects of global warming at low-lying coastal areas of the Arctic and subarctic, where numerous taxa breed, and to assess population recovery throughout their range. We estimated population sizes on the Yukon-Kuskokwim Delta in western Alaska on the eastern edge of the Bering Sea. We conducted ground-based surveys during 2015 and 2016 at 589 randomly selected plots from an area of 35,769 km2. We used stratified random sampling in 8 physiographic strata and corrected population estimates using detection ratios derived from double sampling on a subset of plots. We detected 11,110 breeding individuals of 21 taxa. Western Sandpiper (Calidris mauri), Red-necked Phalarope (Phalaropus lobatus), Dunlin (subspecies C. alpina pacifica), and Wilson’s Snipe (Gallinago delicata) were the most abundant taxa. We estimated that ~6.9 million individual shorebirds were breeding on the entire Yukon-Kuskokwim Delta in 2015 and 2016. Our surveys of this region provided robust population estimates (CVs ≤ 0.35) for 14 species. Our results indicate that the Yukon-Kuskokwim Delta supports a large proportion of North America’s breeding populations of the Pacific Golden-Plover (Pluvialis fulva), the western population of a Whimbrel subspecies (Numenius phaeopus hudsonicus), a Bar-tailed Godwit subspecies (Limosa lapponica baueri), Black Turnstone (Arenaria melanocephala), a Dunlin subspecies (Calidris alpina pacifica), and Western Sandpiper. Our study highlights the importance to breeding shorebirds of this relatively pristine but climatically sensitive deltaic system. Estuaries and deltaic systems worldwide are rapidly being degraded by anthropogenic activities. Our population estimates can be used to refine prior North American population estimates, determine effects of global warming, and evaluate conservation success by measuring population change over time.
{"title":"Alaska's climate sensitive Yukon-Kuskokwim Delta supports seven million Arctic-breeding shorebirds, including the majority of six North American populations","authors":"James E. Lyons, Stephen C Brown, S. Saalfeld, James A Johnson, B. Andres, Kristine M. Sowl, Robert E Gill, B. Mccaffery, Lindall R. Kidd, Metta McGarvey, Brad Winn, H. Gates, D. Granfors, R. Lanctot","doi":"10.1093/ornithapp/duad066","DOIUrl":"https://doi.org/10.1093/ornithapp/duad066","url":null,"abstract":"\u0000 Baseline information about declining North American shorebird populations is essential to determine the effects of global warming at low-lying coastal areas of the Arctic and subarctic, where numerous taxa breed, and to assess population recovery throughout their range. We estimated population sizes on the Yukon-Kuskokwim Delta in western Alaska on the eastern edge of the Bering Sea. We conducted ground-based surveys during 2015 and 2016 at 589 randomly selected plots from an area of 35,769 km2. We used stratified random sampling in 8 physiographic strata and corrected population estimates using detection ratios derived from double sampling on a subset of plots. We detected 11,110 breeding individuals of 21 taxa. Western Sandpiper (Calidris mauri), Red-necked Phalarope (Phalaropus lobatus), Dunlin (subspecies C. alpina pacifica), and Wilson’s Snipe (Gallinago delicata) were the most abundant taxa. We estimated that ~6.9 million individual shorebirds were breeding on the entire Yukon-Kuskokwim Delta in 2015 and 2016. Our surveys of this region provided robust population estimates (CVs ≤ 0.35) for 14 species. Our results indicate that the Yukon-Kuskokwim Delta supports a large proportion of North America’s breeding populations of the Pacific Golden-Plover (Pluvialis fulva), the western population of a Whimbrel subspecies (Numenius phaeopus hudsonicus), a Bar-tailed Godwit subspecies (Limosa lapponica baueri), Black Turnstone (Arenaria melanocephala), a Dunlin subspecies (Calidris alpina pacifica), and Western Sandpiper. Our study highlights the importance to breeding shorebirds of this relatively pristine but climatically sensitive deltaic system. Estuaries and deltaic systems worldwide are rapidly being degraded by anthropogenic activities. Our population estimates can be used to refine prior North American population estimates, determine effects of global warming, and evaluate conservation success by measuring population change over time.","PeriodicalId":125764,"journal":{"name":"Ornithological Applications","volume":"65 18","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138945749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-21DOI: 10.1093/ornithapp/duad065
Benjamin Hack, C. A. Cansler, M. Z. Peery, Connor M. Wood
Climate change, management legacies, pest outbreaks, and fire regimes are combining to pose a growing risk of broad-scale loss of forest cover throughout western North America. Already, habitat changes have been linked with declines in numerous bird species; understanding the relative importance of management regimes and habitat structure may be critical to conserving at-risk species. The Olive-sided Flycatcher (Contopus cooperi) is a declining songbird associated with tall, open forests in California’s Sierra Nevada, the core of its breeding range, where the management regimes of the National Park Service (NPS) and U.S. Forest Service (USFS) have led to divergent forest conditions over the past century. We combined a landscape-scale passive acoustic monitoring program, the BirdNET animal sound identification algorithm, and single-season occupancy models to explore the relationships between Olive-sided Flycatchers in the Sierra Nevada and both management regime and fine-scale forest structure. Olive-sided Flycatcher site occupancy increased as canopy cover decreased relative to mean tree diameter, which is consistent with their preference for mature, open forests. These “open forest” conditions were most prevalent on NPS-managed lands, which is consistent with the assumption that the NPS management regime is more faithful to the historical conditions that had supported a larger Olive-sided Flycatcher population than at present. Thus, the support we found for a positive association with USFS-managed lands after controlling for “open forest” suggests that other habitat features are also important. Our results suggest that conservation strategies for Olive-sided Flycatcher breeding habitat should prioritize the protection and generation of open canopies in areas with large trees, as well as the identification of other important habitat features. Prescribed fire, mechanical thinning, and a return of indigenous forest management practices could help to restore historical forest and fire conditions beneficial to this and other species with similar habitat requirements. Fine-scale alterations to forest structure can be implemented much more rapidly and at much broader scales than the imposition of strict protected status, suggesting that there may be multiple pathways to conservation when species respond to habitat at fine spatial scales.
{"title":"Fine-scale forest structure, not management regime, drives occupancy of a declining songbird, the Olive-sided Flycatcher, in the core of its range","authors":"Benjamin Hack, C. A. Cansler, M. Z. Peery, Connor M. Wood","doi":"10.1093/ornithapp/duad065","DOIUrl":"https://doi.org/10.1093/ornithapp/duad065","url":null,"abstract":"\u0000 Climate change, management legacies, pest outbreaks, and fire regimes are combining to pose a growing risk of broad-scale loss of forest cover throughout western North America. Already, habitat changes have been linked with declines in numerous bird species; understanding the relative importance of management regimes and habitat structure may be critical to conserving at-risk species. The Olive-sided Flycatcher (Contopus cooperi) is a declining songbird associated with tall, open forests in California’s Sierra Nevada, the core of its breeding range, where the management regimes of the National Park Service (NPS) and U.S. Forest Service (USFS) have led to divergent forest conditions over the past century. We combined a landscape-scale passive acoustic monitoring program, the BirdNET animal sound identification algorithm, and single-season occupancy models to explore the relationships between Olive-sided Flycatchers in the Sierra Nevada and both management regime and fine-scale forest structure. Olive-sided Flycatcher site occupancy increased as canopy cover decreased relative to mean tree diameter, which is consistent with their preference for mature, open forests. These “open forest” conditions were most prevalent on NPS-managed lands, which is consistent with the assumption that the NPS management regime is more faithful to the historical conditions that had supported a larger Olive-sided Flycatcher population than at present. Thus, the support we found for a positive association with USFS-managed lands after controlling for “open forest” suggests that other habitat features are also important. Our results suggest that conservation strategies for Olive-sided Flycatcher breeding habitat should prioritize the protection and generation of open canopies in areas with large trees, as well as the identification of other important habitat features. Prescribed fire, mechanical thinning, and a return of indigenous forest management practices could help to restore historical forest and fire conditions beneficial to this and other species with similar habitat requirements. Fine-scale alterations to forest structure can be implemented much more rapidly and at much broader scales than the imposition of strict protected status, suggesting that there may be multiple pathways to conservation when species respond to habitat at fine spatial scales.","PeriodicalId":125764,"journal":{"name":"Ornithological Applications","volume":"69 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138948143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-05DOI: 10.1093/ornithapp/duad046
Henry C Stevens, Adam C Smith, Evan R Buechley, Ç. Şekercioğlu, V. Shirey, Kenneth V. Rosenberg, F. L. La Sorte, Douglas Tallamy, Peter P. Marra
Species declines and extinctions characterize the Anthropocene. Determining species vulnerability to decline, and where and how to mitigate threats, are paramount for effective conservation. We hypothesized that species with shared ecological traits also share threats, and therefore may experience similar population trends. Here, we used a Bayesian modeling framework to test whether phylogeny, geography, and 22 ecological traits predict regional population trends for 380 North American bird species. Groups like blackbirds, warblers, and shorebirds, as well as species occupying Bird Conservation Regions at more extreme latitudes in North America, exhibited negative population trends; whereas groups such as ducks, raptors, and waders, as well as species occupying more inland Bird Conservation Regions, exhibited positive trends. Specifically, we found that in addition to phylogeny and breeding geography, multiple ecological traits contributed to explaining variation in regional population trends for North American birds. Furthermore, we found that regional trends and the relative effects of migration distance, phylogeny, and geography differ between shorebirds, songbirds, and waterbirds. Our work provides evidence that multiple ecological traits correlate with North American bird population trends, but that the individual effects of these ecological traits in predicting population trends often vary between different groups of birds. Moreover, our results reinforce the notion that variation in avian population trends is controlled by more than phylogeny and geography, where closely-related species within one region can show unique population trends due to differences in their ecological traits. We recommend that regional conservation plans, i.e. one-size-fits-all plans, be implemented only for bird groups with population trends under strong phylogenetic or geographic controls. We underscore the need to develop species-specific research and management strategies for other groups, like songbirds, that exhibit high variation in their population trends and are influenced by multiple ecological traits.
{"title":"Species-specific ecological traits, phylogeny, and geography underpin vulnerability to population declines for North American birds","authors":"Henry C Stevens, Adam C Smith, Evan R Buechley, Ç. Şekercioğlu, V. Shirey, Kenneth V. Rosenberg, F. L. La Sorte, Douglas Tallamy, Peter P. Marra","doi":"10.1093/ornithapp/duad046","DOIUrl":"https://doi.org/10.1093/ornithapp/duad046","url":null,"abstract":"\u0000 Species declines and extinctions characterize the Anthropocene. Determining species vulnerability to decline, and where and how to mitigate threats, are paramount for effective conservation. We hypothesized that species with shared ecological traits also share threats, and therefore may experience similar population trends. Here, we used a Bayesian modeling framework to test whether phylogeny, geography, and 22 ecological traits predict regional population trends for 380 North American bird species. Groups like blackbirds, warblers, and shorebirds, as well as species occupying Bird Conservation Regions at more extreme latitudes in North America, exhibited negative population trends; whereas groups such as ducks, raptors, and waders, as well as species occupying more inland Bird Conservation Regions, exhibited positive trends. Specifically, we found that in addition to phylogeny and breeding geography, multiple ecological traits contributed to explaining variation in regional population trends for North American birds. Furthermore, we found that regional trends and the relative effects of migration distance, phylogeny, and geography differ between shorebirds, songbirds, and waterbirds. Our work provides evidence that multiple ecological traits correlate with North American bird population trends, but that the individual effects of these ecological traits in predicting population trends often vary between different groups of birds. Moreover, our results reinforce the notion that variation in avian population trends is controlled by more than phylogeny and geography, where closely-related species within one region can show unique population trends due to differences in their ecological traits. We recommend that regional conservation plans, i.e. one-size-fits-all plans, be implemented only for bird groups with population trends under strong phylogenetic or geographic controls. We underscore the need to develop species-specific research and management strategies for other groups, like songbirds, that exhibit high variation in their population trends and are influenced by multiple ecological traits.","PeriodicalId":125764,"journal":{"name":"Ornithological Applications","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114822979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-11DOI: 10.1093/ornithapp/duad032
Shailee S. Shah
{"title":"How Birds Live Together: Colonies and Communities in the Avian World","authors":"Shailee S. Shah","doi":"10.1093/ornithapp/duad032","DOIUrl":"https://doi.org/10.1093/ornithapp/duad032","url":null,"abstract":"","PeriodicalId":125764,"journal":{"name":"Ornithological Applications","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123800618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-08DOI: 10.1093/ornithapp/duad037
Olga Egea-Casas, P. López‐López, Ernesto Álvarez, G. Cortone, Manuel Gal&án, J. J. Iglesias-Lebrija, M. Lo Valvo, Juan Martinez, Stefania Merlino, Carlota Viada, M. Di Vittorio
Reintroduction projects are gaining popularity; however, their relatively elevated cost and chance of failure make them debatable, hence assessing their effectiveness is essential. Within the early stages of raptors, the post-fledging dependency period (PFDP) is the one in which individuals must face dangers without having completely developed their skills. Thereby, comparing PFDP patterns concerning reintroduced and wild individuals is of major interest as it would help to plan and improve future conservation actions. We analyzed the behavior of 38 juvenile Bonelli’s Eagles (Aquila fasciata) (15 reintroduced and 23 wild) tracked through GPS telemetry, tagged as nestlings in 2 insular environments. The study period encompassed 9-yr movement data from reintroduced chicks in Mallorca (Spain) and wild chicks from Sicily (Italy). Movement parameters (i.e., age of first flight, age of dispersal, length of the PFDP, revisits to the natal or release area, and residence time in them) were analyzed together with their behavior for reintroduced and wild individuals. Similar movement patterns were obtained for both origins, although wild individuals revisited the natal site more often and dispersed earlier. Behavior was also similar, though it varied throughout the PFDP, observing a more abrupt progress in wild individuals and an earlier development of travelling and hunting behaviors. Observed differences are probably related to food availability, which can improve body condition and thus delay onset of dispersal, together with parental presence, which can prompt an earlier ending of the PFDP by encouraging juvenile independence. In conclusion, our study provides valuable insights into the behavior of reintroduced Bonelli’s Eagles during their PFDP and how it compares to their wild counterparts. Our results suggest that reintroduced individuals can successfully adapt to their environment and behave similarly to wild individuals. These findings can aid in the planning and improvement of future reintroduction projects and conservation actions for this endangered species.
{"title":"Similar post-fledging behavior observed in wild and reintroduced juvenile Bonelli’s Eagle in two Mediterranean islands","authors":"Olga Egea-Casas, P. López‐López, Ernesto Álvarez, G. Cortone, Manuel Gal&án, J. J. Iglesias-Lebrija, M. Lo Valvo, Juan Martinez, Stefania Merlino, Carlota Viada, M. Di Vittorio","doi":"10.1093/ornithapp/duad037","DOIUrl":"https://doi.org/10.1093/ornithapp/duad037","url":null,"abstract":"\u0000 Reintroduction projects are gaining popularity; however, their relatively elevated cost and chance of failure make them debatable, hence assessing their effectiveness is essential. Within the early stages of raptors, the post-fledging dependency period (PFDP) is the one in which individuals must face dangers without having completely developed their skills. Thereby, comparing PFDP patterns concerning reintroduced and wild individuals is of major interest as it would help to plan and improve future conservation actions. We analyzed the behavior of 38 juvenile Bonelli’s Eagles (Aquila fasciata) (15 reintroduced and 23 wild) tracked through GPS telemetry, tagged as nestlings in 2 insular environments. The study period encompassed 9-yr movement data from reintroduced chicks in Mallorca (Spain) and wild chicks from Sicily (Italy). Movement parameters (i.e., age of first flight, age of dispersal, length of the PFDP, revisits to the natal or release area, and residence time in them) were analyzed together with their behavior for reintroduced and wild individuals. Similar movement patterns were obtained for both origins, although wild individuals revisited the natal site more often and dispersed earlier. Behavior was also similar, though it varied throughout the PFDP, observing a more abrupt progress in wild individuals and an earlier development of travelling and hunting behaviors. Observed differences are probably related to food availability, which can improve body condition and thus delay onset of dispersal, together with parental presence, which can prompt an earlier ending of the PFDP by encouraging juvenile independence. In conclusion, our study provides valuable insights into the behavior of reintroduced Bonelli’s Eagles during their PFDP and how it compares to their wild counterparts. Our results suggest that reintroduced individuals can successfully adapt to their environment and behave similarly to wild individuals. These findings can aid in the planning and improvement of future reintroduction projects and conservation actions for this endangered species.","PeriodicalId":125764,"journal":{"name":"Ornithological Applications","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128862952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-01DOI: 10.1093/ornithapp/duad036
T. Birkhead, R. Montgomerie
Climate change has resulted in a marked advancement in the breeding phenology of many bird species. Since the timing of many monitoring programmes is based on calendar dates, changes in the timing of birds’ breeding seasons may result in a mismatch with the census period. Using data from a long-term population study of Common Murres (Uria aalge; Common Guillemots in Europe) on Skomer Island, Wales, together with simulations, we show that the 2-week advance in the timing of breeding in Common Murres between 1973 and 2020 has serious implications for the timing of census counts. We show that because censuses have traditionally been conducted during the same fixed calendar period each year, the size of the breeding population has been underestimated. We recommend that censuses of breeding seabirds be made relative to the median egg-laying date rather than on specific calendar dates. Since climate change has resulted in a widespread advance in the timing of birds’ breeding seasons in the northern hemisphere, our results may be relevant to Common Murres at other colonies, and to other bird species worldwide.
{"title":"Census counts of Common Murres adjusted for timing of breeding are more accurate than counts based on calendar dates","authors":"T. Birkhead, R. Montgomerie","doi":"10.1093/ornithapp/duad036","DOIUrl":"https://doi.org/10.1093/ornithapp/duad036","url":null,"abstract":"\u0000 Climate change has resulted in a marked advancement in the breeding phenology of many bird species. Since the timing of many monitoring programmes is based on calendar dates, changes in the timing of birds’ breeding seasons may result in a mismatch with the census period. Using data from a long-term population study of Common Murres (Uria aalge; Common Guillemots in Europe) on Skomer Island, Wales, together with simulations, we show that the 2-week advance in the timing of breeding in Common Murres between 1973 and 2020 has serious implications for the timing of census counts. We show that because censuses have traditionally been conducted during the same fixed calendar period each year, the size of the breeding population has been underestimated. We recommend that censuses of breeding seabirds be made relative to the median egg-laying date rather than on specific calendar dates. Since climate change has resulted in a widespread advance in the timing of birds’ breeding seasons in the northern hemisphere, our results may be relevant to Common Murres at other colonies, and to other bird species worldwide.","PeriodicalId":125764,"journal":{"name":"Ornithological Applications","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130302417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-01DOI: 10.1093/ornithapp/duad035
Victoria C Concha, Julián Caviedes, F. Novoa, Tomás A. Altamirano, J. Ibarra
The simplification of forest structural complexity, caused by anthropogenic land-use practices, is one of the main threats to understory specialist birds. We examined the association of both single structural attributes and structural complexity, with the density of 4 understory bird species in the Global Biodiversity Hotspot “Chilean Winter Rainfall-Valdivian Forests” of South America. Between 2011 and 2013, we surveyed habitat attributes and conducted bird point counts in 505 plots in Andean temperate ecosystems in Chile. In each habitat plot, we measured understory density, volume of coarse woody debris (CWD), number of snags, diameter at breast height (DBH) of trees, and leaf litter depth. With these attributes, we developed an index of stand structural complexity (ISC). On average, old-growth forests had higher values for understory density, CWD volume, DBH, and litter depth than secondary forests and open fields, and thus greater values of ISC. The density of understory birds was positively correlated with the ISC for the Rhinocryptidae Pteroptochos tarnii, Scelorchilus rubecula, and Scytalopus magellanicus. We also found a positive association between understory density and litter depth, with the density of the Furnariidae Sylviorthorhynchus desmursii. However, this latter species showed a negative association with the density of snags. Our results suggest the utility of using an index of structural complexity, rather than single or even additive habitat attributes, for determining the density of understory specialist birds. We recommend that management plans should promote the retention of habitat attributes that contribute to the structural complexity of temperate forests of South America and beyond.
{"title":"Structural complexity is a better predictor than single habitat attributes of understory bird densities in Andean temperate forests","authors":"Victoria C Concha, Julián Caviedes, F. Novoa, Tomás A. Altamirano, J. Ibarra","doi":"10.1093/ornithapp/duad035","DOIUrl":"https://doi.org/10.1093/ornithapp/duad035","url":null,"abstract":"\u0000 The simplification of forest structural complexity, caused by anthropogenic land-use practices, is one of the main threats to understory specialist birds. We examined the association of both single structural attributes and structural complexity, with the density of 4 understory bird species in the Global Biodiversity Hotspot “Chilean Winter Rainfall-Valdivian Forests” of South America. Between 2011 and 2013, we surveyed habitat attributes and conducted bird point counts in 505 plots in Andean temperate ecosystems in Chile. In each habitat plot, we measured understory density, volume of coarse woody debris (CWD), number of snags, diameter at breast height (DBH) of trees, and leaf litter depth. With these attributes, we developed an index of stand structural complexity (ISC). On average, old-growth forests had higher values for understory density, CWD volume, DBH, and litter depth than secondary forests and open fields, and thus greater values of ISC. The density of understory birds was positively correlated with the ISC for the Rhinocryptidae Pteroptochos tarnii, Scelorchilus rubecula, and Scytalopus magellanicus. We also found a positive association between understory density and litter depth, with the density of the Furnariidae Sylviorthorhynchus desmursii. However, this latter species showed a negative association with the density of snags. Our results suggest the utility of using an index of structural complexity, rather than single or even additive habitat attributes, for determining the density of understory specialist birds. We recommend that management plans should promote the retention of habitat attributes that contribute to the structural complexity of temperate forests of South America and beyond.","PeriodicalId":125764,"journal":{"name":"Ornithological Applications","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134010433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-25DOI: 10.1093/ornithapp/duad033
G. Carter, E. Stolen, D. Breininger, S. A. Legare, D. K. Hunt, Chris D Schumann, W. V. Payne
Juvenile survival in birds is difficult to estimate but this vital rate can be an important consideration for management decisions. We estimated juvenile survival of cooperatively breeding Florida Scrub-Jays (Aphelocoma coerulescens) in a landscape degraded by fire suppression and fragmentation using data from marked (n = 325) and unmarked juveniles (n = 1,306) with an integrated hierarchical Bayesian model. To assess the combined analyses, we also analyzed these datasets separately, with a Cormack-Jolly-Seber (CJS) model (marked) and young model (unmarked). Our data consisted of monthly censuses of territorial family groups from Florida Scrub-Jay populations in East Central Florida collected over a 22-yr period. Juvenile survival was estimated from July when young Florida Scrub-Jays begin developing independence to March when they become first year individuals and grouped according to the habitat quality class of their natal territory that were based on shrub height (with intermediate shrub heights being optimal and short and tall shrub heights being suboptimal) and the presence of sandy openings (the preferred open having many sandy openings; closed not having enough). Parameter estimates in the combined analysis were intermediate to the separate analyses. Notable differences among the separate analyses were that suboptimal habitat survival was lower in the unmarked analysis, the unmarked analysis showed a linear effect of time not seen in the marked analysis, and there was an effect of male breeder death in the marked but not unmarked analysis. The combined data analysis provided more inference than did either data set analyzed separately including juveniles in optimal-closed territories unexpectedly had higher survival than those in optimal-open, survival increased through time, and male breeder death had a negative effect on survival. This study suggests that optimal-closed habitat may play an important role in juvenile Florida Scrub-Jay survival perhaps by providing better cover from predators and warrants further investigation for management implications.
{"title":"Survival of juvenile Florida Scrub-Jays is positively correlated with month and negatively correlated with male breeder death","authors":"G. Carter, E. Stolen, D. Breininger, S. A. Legare, D. K. Hunt, Chris D Schumann, W. V. Payne","doi":"10.1093/ornithapp/duad033","DOIUrl":"https://doi.org/10.1093/ornithapp/duad033","url":null,"abstract":"\u0000 Juvenile survival in birds is difficult to estimate but this vital rate can be an important consideration for management decisions. We estimated juvenile survival of cooperatively breeding Florida Scrub-Jays (Aphelocoma coerulescens) in a landscape degraded by fire suppression and fragmentation using data from marked (n = 325) and unmarked juveniles (n = 1,306) with an integrated hierarchical Bayesian model. To assess the combined analyses, we also analyzed these datasets separately, with a Cormack-Jolly-Seber (CJS) model (marked) and young model (unmarked). Our data consisted of monthly censuses of territorial family groups from Florida Scrub-Jay populations in East Central Florida collected over a 22-yr period. Juvenile survival was estimated from July when young Florida Scrub-Jays begin developing independence to March when they become first year individuals and grouped according to the habitat quality class of their natal territory that were based on shrub height (with intermediate shrub heights being optimal and short and tall shrub heights being suboptimal) and the presence of sandy openings (the preferred open having many sandy openings; closed not having enough). Parameter estimates in the combined analysis were intermediate to the separate analyses. Notable differences among the separate analyses were that suboptimal habitat survival was lower in the unmarked analysis, the unmarked analysis showed a linear effect of time not seen in the marked analysis, and there was an effect of male breeder death in the marked but not unmarked analysis. The combined data analysis provided more inference than did either data set analyzed separately including juveniles in optimal-closed territories unexpectedly had higher survival than those in optimal-open, survival increased through time, and male breeder death had a negative effect on survival. This study suggests that optimal-closed habitat may play an important role in juvenile Florida Scrub-Jay survival perhaps by providing better cover from predators and warrants further investigation for management implications.","PeriodicalId":125764,"journal":{"name":"Ornithological Applications","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130137195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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