Pub Date : 2024-07-19DOI: 10.1093/ornithapp/duae032
Ryan E Brodie, Nicholas J Bayly, Ana M González, Jessica Hightower, Jeffery L Larkin, Rebecca L M Stewart, Scott Wilson, Amber M Roth
Climate and land use/land cover change are expected to influence the stationary nonbreeding distributions of 4 Nearctic–Neotropical migrant bird species experiencing population declines: Cardellina canadensis (Canada Warbler), Setophaga cerulea (Cerulean Warbler), Vermivora chrysoptera (Golden-winged Warbler), and Hylocichla mustelina (Wood Thrush). Understanding how and where these species’ distributions shift in response to environmental drivers is critical to inform conservation planning in the Neotropics. For each species, we quantified current (2012–2021) and projected future (2050) suitable climatic and land use/land cover conditions as components of stationary nonbreeding distributions. Multi-source occurrence data were used in an ensemble modeling approach with covariates from 3 global coupled climate models (CCSM-ESM2, FIO-ESM-2-0, MIROC-ES2L) and 2 shared socioeconomic pathways (SSP2-RCP4.5, SSP5-RCP8.5) to predict distributions in response to varying climatic and land use/land cover conditions. Our findings suggest that distribution contraction, upslope elevational shifts in suitable conditions, and limited shifts in latitude and longitude will occur in 3 of 4 species. Cardellina canadensis and S. cerulea are expected to experience a moderate distribution contraction (7–29% and 19–43%, respectively), primarily in response to expected temperature changes. The V. chrysoptera distribution was modeled by sex, and females and males were projected to experience a major distribution contraction (56–79% loss in suitable conditions for females, 46–65% for males), accompanied by shifts in peak densities to higher elevations with minimal changes in the upper elevation limit. Expected changes in precipitation had the greatest effect on V. chrysoptera. Hylocichla mustelina experienced the smallest distribution change, consistent with the species’ flexibility in habitat selection and broader elevational range. We recommend defining priority areas for conservation as those where suitable conditions are expected to remain or arise in the next 25 years. For V. chrysoptera in particular, it is urgent to ensure that mid-elevation forests in Costa Rica and Honduras are adequately managed and protected.
{"title":"Nonbreeding distributions of four declining Nearctic–Neotropical migrants are predicted to contract under future climate and socioeconomic scenarios","authors":"Ryan E Brodie, Nicholas J Bayly, Ana M González, Jessica Hightower, Jeffery L Larkin, Rebecca L M Stewart, Scott Wilson, Amber M Roth","doi":"10.1093/ornithapp/duae032","DOIUrl":"https://doi.org/10.1093/ornithapp/duae032","url":null,"abstract":"Climate and land use/land cover change are expected to influence the stationary nonbreeding distributions of 4 Nearctic–Neotropical migrant bird species experiencing population declines: Cardellina canadensis (Canada Warbler), Setophaga cerulea (Cerulean Warbler), Vermivora chrysoptera (Golden-winged Warbler), and Hylocichla mustelina (Wood Thrush). Understanding how and where these species’ distributions shift in response to environmental drivers is critical to inform conservation planning in the Neotropics. For each species, we quantified current (2012–2021) and projected future (2050) suitable climatic and land use/land cover conditions as components of stationary nonbreeding distributions. Multi-source occurrence data were used in an ensemble modeling approach with covariates from 3 global coupled climate models (CCSM-ESM2, FIO-ESM-2-0, MIROC-ES2L) and 2 shared socioeconomic pathways (SSP2-RCP4.5, SSP5-RCP8.5) to predict distributions in response to varying climatic and land use/land cover conditions. Our findings suggest that distribution contraction, upslope elevational shifts in suitable conditions, and limited shifts in latitude and longitude will occur in 3 of 4 species. Cardellina canadensis and S. cerulea are expected to experience a moderate distribution contraction (7–29% and 19–43%, respectively), primarily in response to expected temperature changes. The V. chrysoptera distribution was modeled by sex, and females and males were projected to experience a major distribution contraction (56–79% loss in suitable conditions for females, 46–65% for males), accompanied by shifts in peak densities to higher elevations with minimal changes in the upper elevation limit. Expected changes in precipitation had the greatest effect on V. chrysoptera. Hylocichla mustelina experienced the smallest distribution change, consistent with the species’ flexibility in habitat selection and broader elevational range. We recommend defining priority areas for conservation as those where suitable conditions are expected to remain or arise in the next 25 years. For V. chrysoptera in particular, it is urgent to ensure that mid-elevation forests in Costa Rica and Honduras are adequately managed and protected.","PeriodicalId":501493,"journal":{"name":"The Condor: Ornithological Applications","volume":"356 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141769997","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 : 2024-07-13DOI: 10.1093/ornithapp/duae028
Ryan J Fisher, Stephen K Davis
Grassland songbirds breeding in Canada and the United States have experienced significant population declines likely because of habitat loss and degradation. Many climate change models predict an increase in the frequency, intensity, and duration of extreme precipitation and temperature events that could place further pressures on declining species. We monitored the fate of 1,868 individual nesting attempts of 7 grassland songbird species in response to various precipitation and temperature measures over a 10-yr period (1997–2002 and 2004–2008) in Saskatchewan, Canada. Daily nest survival rates of 5 species, including 3 at-risk species, were negatively influenced by high levels of precipitation, although the amount of precipitation where declines in daily nest survival occurred varied. Daily nest survival rates of 2 species were negatively correlated with high temperatures. We failed to detect any relationship between precipitation or temperature and the number of fledglings produced from successful nests. Extreme weather events could add additional stressors to declining populations of grassland birds in Canada. Increases in the frequency and intensity of extreme weather, specifically extreme precipitation events and short-term high temperatures, will likely lead to lower reproductive success for several species compared to current levels. This may be especially problematic for management of Anthus spragueii (Sprague’s Pipit) and Centronyx bairdii (Baird’s Sparrow), where a large proportion (>75%) of the breeding population occurs near the northern edge of the Great Plains. The continuing loss and degradation of northern grasslands may limit the ability of these species to disperse and find favorable climate conditions.
{"title":"Extreme weather has variable effects on reproductive success of grassland songbirds at the northern extent of their range","authors":"Ryan J Fisher, Stephen K Davis","doi":"10.1093/ornithapp/duae028","DOIUrl":"https://doi.org/10.1093/ornithapp/duae028","url":null,"abstract":"Grassland songbirds breeding in Canada and the United States have experienced significant population declines likely because of habitat loss and degradation. Many climate change models predict an increase in the frequency, intensity, and duration of extreme precipitation and temperature events that could place further pressures on declining species. We monitored the fate of 1,868 individual nesting attempts of 7 grassland songbird species in response to various precipitation and temperature measures over a 10-yr period (1997–2002 and 2004–2008) in Saskatchewan, Canada. Daily nest survival rates of 5 species, including 3 at-risk species, were negatively influenced by high levels of precipitation, although the amount of precipitation where declines in daily nest survival occurred varied. Daily nest survival rates of 2 species were negatively correlated with high temperatures. We failed to detect any relationship between precipitation or temperature and the number of fledglings produced from successful nests. Extreme weather events could add additional stressors to declining populations of grassland birds in Canada. Increases in the frequency and intensity of extreme weather, specifically extreme precipitation events and short-term high temperatures, will likely lead to lower reproductive success for several species compared to current levels. This may be especially problematic for management of Anthus spragueii (Sprague’s Pipit) and Centronyx bairdii (Baird’s Sparrow), where a large proportion (>75%) of the breeding population occurs near the northern edge of the Great Plains. The continuing loss and degradation of northern grasslands may limit the ability of these species to disperse and find favorable climate conditions.","PeriodicalId":501493,"journal":{"name":"The Condor: Ornithological Applications","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141719152","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 : 2024-07-12DOI: 10.1093/ornithapp/duae027
Arthur Sanchez Jr., Mackenzie R Roeder, Brian J Olsen, Elisa C Elizondo, Katharine J Ruskin, Alice M Hotopp, Chris S Elphick, Sam E Apgar, Christopher R Field, Jonathan B Cohen, Alison R Kocek, Adrienne I Kovach, Rebecca A Longenecker, W Gregory Shriver
Salt marshes in the northeastern United States provide critical breeding habitat for tidal marsh specialist birds like the Ammospiza caudacuta (Saltmarsh Sparrow). The Ammospiza caudacuta population declined by 9% annually from 1998 to 2012, necessitating immediate conservation actions for this vulnerable species. However, estimating species vital rates across a large geographic region is logistically challenging and cost prohibitive. Therefore, we developed and tested a rapid assessment monitoring protocol focused on reproductive metrics to enhance future conservation planning. We used 3 years (2018, 2019, and 2021) of intensive demographic data from 12 sites to estimate daily nest survival, nest period success, fledglings produced per female, and successful broods per female. We implemented the rapid assessment protocol co-located at intensive sites in the same years to estimate the number of captured females and juveniles. We used Pearson’s correlation analyses to determine the association of intensive metrics with rapid metrics. We found that the sum of Ammospiza caudacuta female and juvenile captures was positively correlated with daily nest survival (r = 0.61, P = 0.01), nest period success (r = 0.70, P = 0.002), fledglings produced per female (r = 0.82, P < 0.001), and successful broods per female (r = 0.82, P < 0.001). Our results demonstrate that fixed-effort mist-netting from our rapid assessment protocol is an informative and time-efficient sampling method that can aid in making informed management decisions related to Ammospiza caudacuta conservation.
{"title":"Positive correlation between Ammospiza caudacuta (Saltmarsh Sparrow) capture and productivity supports use of a novel rapid assessment monitoring protocol","authors":"Arthur Sanchez Jr., Mackenzie R Roeder, Brian J Olsen, Elisa C Elizondo, Katharine J Ruskin, Alice M Hotopp, Chris S Elphick, Sam E Apgar, Christopher R Field, Jonathan B Cohen, Alison R Kocek, Adrienne I Kovach, Rebecca A Longenecker, W Gregory Shriver","doi":"10.1093/ornithapp/duae027","DOIUrl":"https://doi.org/10.1093/ornithapp/duae027","url":null,"abstract":"Salt marshes in the northeastern United States provide critical breeding habitat for tidal marsh specialist birds like the Ammospiza caudacuta (Saltmarsh Sparrow). The Ammospiza caudacuta population declined by 9% annually from 1998 to 2012, necessitating immediate conservation actions for this vulnerable species. However, estimating species vital rates across a large geographic region is logistically challenging and cost prohibitive. Therefore, we developed and tested a rapid assessment monitoring protocol focused on reproductive metrics to enhance future conservation planning. We used 3 years (2018, 2019, and 2021) of intensive demographic data from 12 sites to estimate daily nest survival, nest period success, fledglings produced per female, and successful broods per female. We implemented the rapid assessment protocol co-located at intensive sites in the same years to estimate the number of captured females and juveniles. We used Pearson’s correlation analyses to determine the association of intensive metrics with rapid metrics. We found that the sum of Ammospiza caudacuta female and juvenile captures was positively correlated with daily nest survival (r = 0.61, P = 0.01), nest period success (r = 0.70, P = 0.002), fledglings produced per female (r = 0.82, P &lt; 0.001), and successful broods per female (r = 0.82, P &lt; 0.001). Our results demonstrate that fixed-effort mist-netting from our rapid assessment protocol is an informative and time-efficient sampling method that can aid in making informed management decisions related to Ammospiza caudacuta conservation.","PeriodicalId":501493,"journal":{"name":"The Condor: Ornithological Applications","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141613572","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 : 2024-05-29DOI: 10.1093/ornithapp/duae021
Frank R Thompson III, Thomas W Bonnot, Rebecka L Brasso, Melissa C Roach, Kathy Hixson, David E Mosby
Songbirds incidentally ingest soil contaminated with lead and several species in the Southeast Missouri Lead Mining District have a negative relationship between soil lead concentration and reproduction. We used an individual-based model (IBM) to simulate nesting processes throughout the breeding season to estimate annual productivity for five songbirds in relation to soil-lead concentration. We modeled daily nest survival and number fledged in relation to soil lead and incorporated these relationships into the IBM using a Bayesian approach that fully captured parameter uncertainty and process variation. The proportion of the posterior distribution for the effect of soil lead on daily nest survival was mostly negative for Pipilo erythrophthalmus (Eastern Towhee), Passerina cyanea (Indigo Bunting), Cardinalis cardinalis (Northern Cardinal), and Sialia sialis (Eastern Bluebird; f = 0.972, 0.990, 0.741, 0.581, respectively) and slightly positive for Spizella pusilla (Field Sparrow; f = 0.680). The proportion of the posterior distribution for the effect of soil lead on the number fledged from successful nests was mostly negative for S. pusilla, P. erythrophthalmus, and C. cardinalis (f = 0.867, 0.585, 0.508, respectively) and positive for P. cyanea and S. sialis (f = 0.773, 0.744). Simulated annual productivity decreased by 0.04–1.47 young/female/year among species across the range of soil lead concentrations, with the greatest declines for P. erythrophthalmus and P. cyanea. The probability of fledging one or more young changed from 51% to 15% for P. erythrophthalmus, 57% to 23% for P. cyanea, 60% to 48% for C. cardinalis, 94% to 84% for S. sialis, and 57% to 64% for S. pusilla as soil-lead concentration around a nest increased from 20 to 4000 ppm. Most nest failures were the result of predation; therefore, we suggest lead may have affected birds’ behavior at the nest, or affected nest site quality, which resulted in higher nest predation.
{"title":"Songbird annual productivity declines with increasing soil lead contamination around nests","authors":"Frank R Thompson III, Thomas W Bonnot, Rebecka L Brasso, Melissa C Roach, Kathy Hixson, David E Mosby","doi":"10.1093/ornithapp/duae021","DOIUrl":"https://doi.org/10.1093/ornithapp/duae021","url":null,"abstract":"Songbirds incidentally ingest soil contaminated with lead and several species in the Southeast Missouri Lead Mining District have a negative relationship between soil lead concentration and reproduction. We used an individual-based model (IBM) to simulate nesting processes throughout the breeding season to estimate annual productivity for five songbirds in relation to soil-lead concentration. We modeled daily nest survival and number fledged in relation to soil lead and incorporated these relationships into the IBM using a Bayesian approach that fully captured parameter uncertainty and process variation. The proportion of the posterior distribution for the effect of soil lead on daily nest survival was mostly negative for Pipilo erythrophthalmus (Eastern Towhee), Passerina cyanea (Indigo Bunting), Cardinalis cardinalis (Northern Cardinal), and Sialia sialis (Eastern Bluebird; f = 0.972, 0.990, 0.741, 0.581, respectively) and slightly positive for Spizella pusilla (Field Sparrow; f = 0.680). The proportion of the posterior distribution for the effect of soil lead on the number fledged from successful nests was mostly negative for S. pusilla, P. erythrophthalmus, and C. cardinalis (f = 0.867, 0.585, 0.508, respectively) and positive for P. cyanea and S. sialis (f = 0.773, 0.744). Simulated annual productivity decreased by 0.04–1.47 young/female/year among species across the range of soil lead concentrations, with the greatest declines for P. erythrophthalmus and P. cyanea. The probability of fledging one or more young changed from 51% to 15% for P. erythrophthalmus, 57% to 23% for P. cyanea, 60% to 48% for C. cardinalis, 94% to 84% for S. sialis, and 57% to 64% for S. pusilla as soil-lead concentration around a nest increased from 20 to 4000 ppm. Most nest failures were the result of predation; therefore, we suggest lead may have affected birds’ behavior at the nest, or affected nest site quality, which resulted in higher nest predation.","PeriodicalId":501493,"journal":{"name":"The Condor: Ornithological Applications","volume":"329 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141194144","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 : 2024-05-13DOI: 10.1093/ornithapp/duae017
Sarah H Peterson, Joshua T Ackerman, C Alex Hartman, Andrew C Greenawalt, Michael L Casazza, Mark P Herzog
Waterfowl population recruitment is sensitive to duckling survival. We quantified predator types and survival rates for Anas platyrhynchos (Mallard) and Mareca strepera (Gadwall) ducklings in one of the largest brackish water marshes in western North America (Suisun Marsh, California) using 556 radio-tagged ducklings from 284 broods tracked during the 2016 to 2019 breeding seasons. Overall, 78% of ducklings died and 84% of mortalities occurred <7 days after hatch. After hatching in upland fields, survival was greater for broods that hatched closer to flooded wetlands; broods had a ≥75% chance of surviving the move from the nest to water when nests were located ≤140 m from the nearest wetland and ≤50% chance of surviving when nests were located ≥970 m from the nearest wetland. Predation accounted for 91% of mortalities and was attributed to mammals (27.6%), birds (22.0%), snakes (4.4%), and unknown predators (46.0%). Anas platyrhynchos survival to fledging (54 days) was only 3.2% and 0.9% during two drier years and 11.7% and 16.7% during two wetter years. Mareca strepera survival to fledging was 9.4% to 11.2% among years. Daily survival rates for ducklings generally increased with the amount of flooded wetland within 0.5 km (A. platyrhynchos) and 1.0 km (M. strepera) of the nest at hatch. Additionally, survival rates increased with duckling age and body mass at hatch for both species and decreased with hatch date for A. platyrhynchos but not M. strepera, which may be partially due to the earlier onset of A. platyrhynchos nesting. For ducklings that survived the initial move to water, survival rates were negatively correlated with salinity and this effect was more pronounced for younger ducklings. Anas platyrhynchos survival to 7 days post hatch decreased by 9.1% (wetter year) to 31.4% (drier year) when ducklings were in 12 ppt water (99th quantile of cumulative salinity concentrations experienced by ducklings) versus 0.5 ppt water. Mareca strepera survival to 7 days decreased by 7.4% when ducklings were in 12 ppt versus 0.5 ppt water. Our results suggest that maintaining a network of low salinity wetlands within 1 km of upland nesting sites would likely improve duckling survival rates, especially during the critical 7-day period after hatch.
{"title":"Duckling survival increased with availability of flooded wetland habitat and decreased with salinity concentrations in a brackish marsh","authors":"Sarah H Peterson, Joshua T Ackerman, C Alex Hartman, Andrew C Greenawalt, Michael L Casazza, Mark P Herzog","doi":"10.1093/ornithapp/duae017","DOIUrl":"https://doi.org/10.1093/ornithapp/duae017","url":null,"abstract":"Waterfowl population recruitment is sensitive to duckling survival. We quantified predator types and survival rates for Anas platyrhynchos (Mallard) and Mareca strepera (Gadwall) ducklings in one of the largest brackish water marshes in western North America (Suisun Marsh, California) using 556 radio-tagged ducklings from 284 broods tracked during the 2016 to 2019 breeding seasons. Overall, 78% of ducklings died and 84% of mortalities occurred &lt;7 days after hatch. After hatching in upland fields, survival was greater for broods that hatched closer to flooded wetlands; broods had a ≥75% chance of surviving the move from the nest to water when nests were located ≤140 m from the nearest wetland and ≤50% chance of surviving when nests were located ≥970 m from the nearest wetland. Predation accounted for 91% of mortalities and was attributed to mammals (27.6%), birds (22.0%), snakes (4.4%), and unknown predators (46.0%). Anas platyrhynchos survival to fledging (54 days) was only 3.2% and 0.9% during two drier years and 11.7% and 16.7% during two wetter years. Mareca strepera survival to fledging was 9.4% to 11.2% among years. Daily survival rates for ducklings generally increased with the amount of flooded wetland within 0.5 km (A. platyrhynchos) and 1.0 km (M. strepera) of the nest at hatch. Additionally, survival rates increased with duckling age and body mass at hatch for both species and decreased with hatch date for A. platyrhynchos but not M. strepera, which may be partially due to the earlier onset of A. platyrhynchos nesting. For ducklings that survived the initial move to water, survival rates were negatively correlated with salinity and this effect was more pronounced for younger ducklings. Anas platyrhynchos survival to 7 days post hatch decreased by 9.1% (wetter year) to 31.4% (drier year) when ducklings were in 12 ppt water (99th quantile of cumulative salinity concentrations experienced by ducklings) versus 0.5 ppt water. Mareca strepera survival to 7 days decreased by 7.4% when ducklings were in 12 ppt versus 0.5 ppt water. Our results suggest that maintaining a network of low salinity wetlands within 1 km of upland nesting sites would likely improve duckling survival rates, especially during the critical 7-day period after hatch.","PeriodicalId":501493,"journal":{"name":"The Condor: Ornithological Applications","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140929393","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 : 2024-05-08DOI: 10.1093/ornithapp/duae012
Mercy E Harris, Keith A Hobson, Christy A Morrissey
Aerial insectivorous birds breeding in North America have experienced decades of population declines for reasons hypothesized to be related to changes in their insect prey. In agricultural landscapes, land management practices affect insect communities, leading to concerns that ongoing trends toward more intensive cultivation could affect the ability of farmland-breeding aerial insectivores to forage and provision their offspring with aerial insect prey. To understand how differences in agricultural intensity may affect the foraging behavior of different aerial insectivore species, we used GPS tags to compare the foraging movements and foraging habitat use of 2 species with different foraging ecologies, Hirundo rustica (Barn Swallow) and Tachycineta bicolor (Tree Swallow), breeding at 17 sites in agricultural landscapes in Saskatchewan, Canada. Although we identified differences in foraging behavior consistent with each species’ reported ecological traits, including T. bicolor foraging farther and over larger areas than H. rustica, overall foraging behavior was similar between species. Resource selection function analyses indicated that both species used wetlands disproportionately often relative to local wetland availability, especially when detected farther from their nests. Hirundo rustica and T. bicolor both also avoided cropped foraging habitat, using it proportionally less than it was locally available. In landscapes with greater wetland cover, both species selected for wetland habitat more strongly, and among T. bicolor, higher wetland density decreased maximum foraging distance and home range area. In contrast, we found no effect of crop cover on foraging habitat selection or foraging movements. These findings suggest that H. rustica and T. bicolor breeding in Saskatchewan agroecosystems share similar foraging strategies, with wetland habitats appearing to be highly important despite comprising only a small proportion of land area. Overall, these results indicate that protecting wetland habitats should be a priority for aerial insectivore conservation in the intensive agricultural landscapes of the Canadian prairies.
{"title":"Hirundo rustica (Barn Swallows) and Tachycineta bicolor (Tree Swallows) select wetlands in agriculturally intensive landscapes, as revealed by GPS tracking","authors":"Mercy E Harris, Keith A Hobson, Christy A Morrissey","doi":"10.1093/ornithapp/duae012","DOIUrl":"https://doi.org/10.1093/ornithapp/duae012","url":null,"abstract":"Aerial insectivorous birds breeding in North America have experienced decades of population declines for reasons hypothesized to be related to changes in their insect prey. In agricultural landscapes, land management practices affect insect communities, leading to concerns that ongoing trends toward more intensive cultivation could affect the ability of farmland-breeding aerial insectivores to forage and provision their offspring with aerial insect prey. To understand how differences in agricultural intensity may affect the foraging behavior of different aerial insectivore species, we used GPS tags to compare the foraging movements and foraging habitat use of 2 species with different foraging ecologies, Hirundo rustica (Barn Swallow) and Tachycineta bicolor (Tree Swallow), breeding at 17 sites in agricultural landscapes in Saskatchewan, Canada. Although we identified differences in foraging behavior consistent with each species’ reported ecological traits, including T. bicolor foraging farther and over larger areas than H. rustica, overall foraging behavior was similar between species. Resource selection function analyses indicated that both species used wetlands disproportionately often relative to local wetland availability, especially when detected farther from their nests. Hirundo rustica and T. bicolor both also avoided cropped foraging habitat, using it proportionally less than it was locally available. In landscapes with greater wetland cover, both species selected for wetland habitat more strongly, and among T. bicolor, higher wetland density decreased maximum foraging distance and home range area. In contrast, we found no effect of crop cover on foraging habitat selection or foraging movements. These findings suggest that H. rustica and T. bicolor breeding in Saskatchewan agroecosystems share similar foraging strategies, with wetland habitats appearing to be highly important despite comprising only a small proportion of land area. Overall, these results indicate that protecting wetland habitats should be a priority for aerial insectivore conservation in the intensive agricultural landscapes of the Canadian prairies.","PeriodicalId":501493,"journal":{"name":"The Condor: Ornithological Applications","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140929458","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 : 2024-03-16DOI: 10.1093/ornithapp/duae011
Brock Geary, Lisa Williams, C Robert Long, Reina M Tyl, Roderick B Gagne
Using data from the mid-1990s to the present, we assessed correlations of Ruffed Grouse (Bonasa umbellus) hunter cooperator reports from seven states to Breeding Bird Survey, Christmas Bird Count, and eBird data to determine which program’s trends best reflected patterns seen in hunter-sourced data that has historically been used for monitoring purposes. Christmas Bird Count data most closely reflected state-wide long-term trends in cooperator flush rates. Using an analytical approach that accounts for sources of bias and examines abundance at a finer spatial scale, we observed a pattern of decline across our study area. In recent decades, Ruffed Grouse populations in the eastern United States are thought to have suffered persistent declines due to a combination of young forest habitat loss and West Nile virus mortality. Declining hunter participation in much of the species’ range has highlighted the need to identify harvest-independent indices of grouse abundance to enable continued monitoring of regional long-term trends. Recent analytical methods can better capture complex trends in population dynamics, account for biases inherent to community-sourced data, and potentially inform designs of future survey efforts aimed at fulfilling priority monitoring and research needs. Comparable results across varying statistical methodologies suggest that our inferences are robust, demonstrating that Christmas Bird Count data can be used to inform regional monitoring efforts for grouse and other cryptic game bird populations, but require careful consideration of program designs and protocols to identify and implement data appropriately.
{"title":"Christmas Bird Count data are a reliable harvest-independent index for Ruffed Grouse monitoring in the eastern United States","authors":"Brock Geary, Lisa Williams, C Robert Long, Reina M Tyl, Roderick B Gagne","doi":"10.1093/ornithapp/duae011","DOIUrl":"https://doi.org/10.1093/ornithapp/duae011","url":null,"abstract":"Using data from the mid-1990s to the present, we assessed correlations of Ruffed Grouse (Bonasa umbellus) hunter cooperator reports from seven states to Breeding Bird Survey, Christmas Bird Count, and eBird data to determine which program’s trends best reflected patterns seen in hunter-sourced data that has historically been used for monitoring purposes. Christmas Bird Count data most closely reflected state-wide long-term trends in cooperator flush rates. Using an analytical approach that accounts for sources of bias and examines abundance at a finer spatial scale, we observed a pattern of decline across our study area. In recent decades, Ruffed Grouse populations in the eastern United States are thought to have suffered persistent declines due to a combination of young forest habitat loss and West Nile virus mortality. Declining hunter participation in much of the species’ range has highlighted the need to identify harvest-independent indices of grouse abundance to enable continued monitoring of regional long-term trends. Recent analytical methods can better capture complex trends in population dynamics, account for biases inherent to community-sourced data, and potentially inform designs of future survey efforts aimed at fulfilling priority monitoring and research needs. Comparable results across varying statistical methodologies suggest that our inferences are robust, demonstrating that Christmas Bird Count data can be used to inform regional monitoring efforts for grouse and other cryptic game bird populations, but require careful consideration of program designs and protocols to identify and implement data appropriately.","PeriodicalId":501493,"journal":{"name":"The Condor: Ornithological Applications","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140151093","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 : 2024-02-28DOI: 10.1093/ornithapp/duae010
Korin Reznikov, Ron Efrat, Oded Berger-Tal, Nir Sapir
Many vulture populations have severely declined in the past decades, showing high juvenile mortality. To support these populations, feeding stations are used to increase food availability and to supply food without antibiotics and toxic compounds. Yet, supplying food at feeding stations may affect vulture behavior. We present a large-scale field experiment testing how different food provision schemes affected the movement of Egyptian Vultures (Neophron percnopterus). We used GPS transmitters harnessed to 18 vulture chicks and described their movements post-fledging. We categorized the vultures into 3 groups according to the feeding scheme used at feeding stations near their nests: frequent and spatially dispersed food supply (FD); non-frequent and spatially dispersed food supply (NFD); and frequent food supply, concentrated in one location (FC). We found that birds from all three groups increased their roosting distances from the nest with fledgling age, with the NFD and FC groups showing a greater increase than the FD group. Additionally, all 3 groups increased their daily flight distances, with the NFD group presenting the largest increase and the FD group presenting the smallest increase. Our findings offer new insights into the relevance of spatiotemporal differences in the management of feeding stations and show its effect on movement during birds’ early life stages, creating 2 main movement patterns: local and regional. Our findings can help decide upon the preferable feeding scheme in a way that will either encourage or reduce the early dispersal distances of fledglings, according to long- and short-term conservation objectives. For example, local movements during the post fledging period to known and stable food resources may reduce the risk of anthropogenic-induced mortality, while it may negatively affect long-term survival by hindering foraging, flight, and exploring skills and affect dispersion to future breeding sites.
{"title":"The spatiotemporal properties of artificial feeding schemes influence the post-fledging movement of Egyptian Vultures","authors":"Korin Reznikov, Ron Efrat, Oded Berger-Tal, Nir Sapir","doi":"10.1093/ornithapp/duae010","DOIUrl":"https://doi.org/10.1093/ornithapp/duae010","url":null,"abstract":"Many vulture populations have severely declined in the past decades, showing high juvenile mortality. To support these populations, feeding stations are used to increase food availability and to supply food without antibiotics and toxic compounds. Yet, supplying food at feeding stations may affect vulture behavior. We present a large-scale field experiment testing how different food provision schemes affected the movement of Egyptian Vultures (Neophron percnopterus). We used GPS transmitters harnessed to 18 vulture chicks and described their movements post-fledging. We categorized the vultures into 3 groups according to the feeding scheme used at feeding stations near their nests: frequent and spatially dispersed food supply (FD); non-frequent and spatially dispersed food supply (NFD); and frequent food supply, concentrated in one location (FC). We found that birds from all three groups increased their roosting distances from the nest with fledgling age, with the NFD and FC groups showing a greater increase than the FD group. Additionally, all 3 groups increased their daily flight distances, with the NFD group presenting the largest increase and the FD group presenting the smallest increase. Our findings offer new insights into the relevance of spatiotemporal differences in the management of feeding stations and show its effect on movement during birds’ early life stages, creating 2 main movement patterns: local and regional. Our findings can help decide upon the preferable feeding scheme in a way that will either encourage or reduce the early dispersal distances of fledglings, according to long- and short-term conservation objectives. For example, local movements during the post fledging period to known and stable food resources may reduce the risk of anthropogenic-induced mortality, while it may negatively affect long-term survival by hindering foraging, flight, and exploring skills and affect dispersion to future breeding sites.","PeriodicalId":501493,"journal":{"name":"The Condor: Ornithological Applications","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140009069","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 : 2024-02-26DOI: 10.1093/ornithapp/duae009
Amy G Vandergast, Barbara E Kus, Dustin A Wood, Anna Mitelberg, Julia G Smith, Elizabeth R Milano
Increasingly, genomic data are being used to supplement field-based ecological studies to help evaluate recovery status and trends in endangered species. We collected genomic data to address two related questions regarding the Least Bell’s Vireo (Vireo bellii), an endangered migratory songbird restricted to southern California riparian habitat for breeding. First, we sought to delineate the range limits and potential overlap between Least Bell’s Vireo and its sister subspecies, the Arizona Bell’s Vireo, by analyzing samples from the deserts of eastern California, southwestern Nevada, Utah and Arizona. Second, we evaluated genetic structure among Least Bell’s Vireo populations in coastal California and estimated effective population size. Clustering analyses based on 10,571 single nucleotide polymorphisms (SNPs) from 317 samples supported two major groups that aligned closely to the previously defined subspecies ranges. The first cluster included birds in the Central Valley, all coastal drainages, and westernmost deserts of California, with no further sub-structuring among coastal drainages. Almost all birds from the Amargosa River in eastern California and eastward assigned to the second cluster; however, low levels of gene flow were detected across the subspecies groups, with greater rates of gene flow from Arizona Bell’s Vireo to Least Bell’s Vireo than the reverse. Admixed individuals occurred in the California deserts; and although smaller than coastal populations, desert populations may be important for maintaining and replenishing genetic diversity and facilitating the movement of potentially adaptive genes between subspecies. Within Least Bell’s Vireo, local populations in coastal drainages comprised a single genetic population, with some evidence of close relatives distributed across drainages, suggesting these could function as a well-connected metapopulation. These results are consistent with previous Least Bell’s Vireo banding studies that reported high rates of dispersal among drainages. Effective population size for both subspecies was high, suggesting that adaptive potential has been maintained despite previous declines.
{"title":"High inter-population connectivity and occasional gene flow between subspecies improves recovery potential for the endangered Least Bell’s Vireo","authors":"Amy G Vandergast, Barbara E Kus, Dustin A Wood, Anna Mitelberg, Julia G Smith, Elizabeth R Milano","doi":"10.1093/ornithapp/duae009","DOIUrl":"https://doi.org/10.1093/ornithapp/duae009","url":null,"abstract":"Increasingly, genomic data are being used to supplement field-based ecological studies to help evaluate recovery status and trends in endangered species. We collected genomic data to address two related questions regarding the Least Bell’s Vireo (Vireo bellii), an endangered migratory songbird restricted to southern California riparian habitat for breeding. First, we sought to delineate the range limits and potential overlap between Least Bell’s Vireo and its sister subspecies, the Arizona Bell’s Vireo, by analyzing samples from the deserts of eastern California, southwestern Nevada, Utah and Arizona. Second, we evaluated genetic structure among Least Bell’s Vireo populations in coastal California and estimated effective population size. Clustering analyses based on 10,571 single nucleotide polymorphisms (SNPs) from 317 samples supported two major groups that aligned closely to the previously defined subspecies ranges. The first cluster included birds in the Central Valley, all coastal drainages, and westernmost deserts of California, with no further sub-structuring among coastal drainages. Almost all birds from the Amargosa River in eastern California and eastward assigned to the second cluster; however, low levels of gene flow were detected across the subspecies groups, with greater rates of gene flow from Arizona Bell’s Vireo to Least Bell’s Vireo than the reverse. Admixed individuals occurred in the California deserts; and although smaller than coastal populations, desert populations may be important for maintaining and replenishing genetic diversity and facilitating the movement of potentially adaptive genes between subspecies. Within Least Bell’s Vireo, local populations in coastal drainages comprised a single genetic population, with some evidence of close relatives distributed across drainages, suggesting these could function as a well-connected metapopulation. These results are consistent with previous Least Bell’s Vireo banding studies that reported high rates of dispersal among drainages. Effective population size for both subspecies was high, suggesting that adaptive potential has been maintained despite previous declines.","PeriodicalId":501493,"journal":{"name":"The Condor: Ornithological Applications","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139978930","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 : 2024-02-17DOI: 10.1093/ornithapp/duae008
Carine Dantas Oliveira, Cintia Cornelius, Philip C Stouffer, Kristina L Cockle
Passive restoration of secondary forests can partially offset loss of biodiversity following tropical deforestation. Tree cavities, an essential resource for cavity-nesting birds, are usually associated with old forest. We investigated the restoration time for tree cavities suitable for cavity-nesting birds in secondary forest at the Biological Dynamics of Forest Fragments Project (BDFFP) in central Amazonian Brazil. We hypothesized that cavity abundance would increase with forest age, but more rapidly in areas exposed to cutting only, compared to areas where forest was cut and burned. We also hypothesized that cavities would be lower, smaller, and less variable in secondary forest than in old-growth forest, which at the BDFFP is part of a vast lowland forest with no recent history of human disturbance. We used pole-mounted cameras and tree-climbing to survey cavities in 39 plots (each 200 × 40 m) across old-growth forests and 11–34-year-old secondary forests. We used generalized linear models to examine how cavity supply was related to forest age and land-use history (cut only vs cut-and-burn), and principal components analysis to compare cavity characteristics between old-growth and secondary forest. Cavity availability increased with secondary forest age, regardless of land-use history, but the oldest secondary forest (31–34 yr) still had fewer cavities (mean ± SE = 9.8 ± 2.2 cavities ha–1) than old-growth forest (20.5 ± 4.2 cavities ha–1). Moreover, secondary forests lacked cavities that were high and deep, with large entrances—characteristics likely to be important for many species of cavity-nesting birds. Several decades may be necessary to restore cavity supply in secondary Amazonian forests, especially for the largest birds (e.g., forest-falcons and parrots > 190 g). Retention of legacy trees as forest is cleared might help maintain a supply of cavities that could allow earlier recolonization by some species of cavity-nesting birds when cleared areas are abandoned. A Portuguese version of this article is available in Supplementary Material 1.
{"title":"Secondary Amazon rainforest partially recovers tree cavities suitable for nesting birds in 18–34 years","authors":"Carine Dantas Oliveira, Cintia Cornelius, Philip C Stouffer, Kristina L Cockle","doi":"10.1093/ornithapp/duae008","DOIUrl":"https://doi.org/10.1093/ornithapp/duae008","url":null,"abstract":"Passive restoration of secondary forests can partially offset loss of biodiversity following tropical deforestation. Tree cavities, an essential resource for cavity-nesting birds, are usually associated with old forest. We investigated the restoration time for tree cavities suitable for cavity-nesting birds in secondary forest at the Biological Dynamics of Forest Fragments Project (BDFFP) in central Amazonian Brazil. We hypothesized that cavity abundance would increase with forest age, but more rapidly in areas exposed to cutting only, compared to areas where forest was cut and burned. We also hypothesized that cavities would be lower, smaller, and less variable in secondary forest than in old-growth forest, which at the BDFFP is part of a vast lowland forest with no recent history of human disturbance. We used pole-mounted cameras and tree-climbing to survey cavities in 39 plots (each 200 × 40 m) across old-growth forests and 11–34-year-old secondary forests. We used generalized linear models to examine how cavity supply was related to forest age and land-use history (cut only vs cut-and-burn), and principal components analysis to compare cavity characteristics between old-growth and secondary forest. Cavity availability increased with secondary forest age, regardless of land-use history, but the oldest secondary forest (31–34 yr) still had fewer cavities (mean ± SE = 9.8 ± 2.2 cavities ha–1) than old-growth forest (20.5 ± 4.2 cavities ha–1). Moreover, secondary forests lacked cavities that were high and deep, with large entrances—characteristics likely to be important for many species of cavity-nesting birds. Several decades may be necessary to restore cavity supply in secondary Amazonian forests, especially for the largest birds (e.g., forest-falcons and parrots &gt; 190 g). Retention of legacy trees as forest is cleared might help maintain a supply of cavities that could allow earlier recolonization by some species of cavity-nesting birds when cleared areas are abandoned. A Portuguese version of this article is available in Supplementary Material 1.","PeriodicalId":501493,"journal":{"name":"The Condor: Ornithological Applications","volume":"122 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139903195","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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