Pub Date : 2022-10-03DOI: 10.1177/17581559221132189
G. Chiatante
Steppic habitats host an extremely high proportion of birds with unfavourable conservation status in Europe, such as larks. This research aims to both investigate habitat-lark relationships and assess the niche overlap among larks in southern Italy during the breeding season. Studied in particular were the Eurasian Skylark (Alauda arvensis), the Greater Short-toed Lark (Calandrella brachydactyla), the Calandra Lark (Melanocorypha calandra), the Crested Lark (Galerida cristata) and the Woodlark (Lullula arborea). During the 2012 breeding season, 301 point counts were carried out, and these were randomly placed in the study area according to a stratified sampling design. Resource selection probability functions were used to build two models for each species: (i) a binary logistic regression using the presence units as the dependent variable and (ii) a GLM with Poisson’s error distribution using the abundance of larks in each sampling point as the dependent variable. In the first model, the land cover in the cells of a 100-m-grid superimposed onto the study area was used as a covariate, whereas in the second model, the same covariate was measured, but in a 300-m-buffer around the sampling points. Finally, niche overlap was measured by Hurlbert’s Index with bootstrap resampling. Results showed that the Skylark, Short-toed Lark, Calandra Lark and Crested Lark are tightly associated with both non-irrigated crops and dry grasslands, with these species selecting areas in which both habitats are present in particular. Furthermore, there is a strong niche overlap at macrohabitat level among the species, with the exception of the Woodlark, which is an ecotonal species.
{"title":"Habitat use and niche overlap of ground-nesting steppic birds","authors":"G. Chiatante","doi":"10.1177/17581559221132189","DOIUrl":"https://doi.org/10.1177/17581559221132189","url":null,"abstract":"Steppic habitats host an extremely high proportion of birds with unfavourable conservation status in Europe, such as larks. This research aims to both investigate habitat-lark relationships and assess the niche overlap among larks in southern Italy during the breeding season. Studied in particular were the Eurasian Skylark (Alauda arvensis), the Greater Short-toed Lark (Calandrella brachydactyla), the Calandra Lark (Melanocorypha calandra), the Crested Lark (Galerida cristata) and the Woodlark (Lullula arborea). During the 2012 breeding season, 301 point counts were carried out, and these were randomly placed in the study area according to a stratified sampling design. Resource selection probability functions were used to build two models for each species: (i) a binary logistic regression using the presence units as the dependent variable and (ii) a GLM with Poisson’s error distribution using the abundance of larks in each sampling point as the dependent variable. In the first model, the land cover in the cells of a 100-m-grid superimposed onto the study area was used as a covariate, whereas in the second model, the same covariate was measured, but in a 300-m-buffer around the sampling points. Finally, niche overlap was measured by Hurlbert’s Index with bootstrap resampling. Results showed that the Skylark, Short-toed Lark, Calandra Lark and Crested Lark are tightly associated with both non-irrigated crops and dry grasslands, with these species selecting areas in which both habitats are present in particular. Furthermore, there is a strong niche overlap at macrohabitat level among the species, with the exception of the Woodlark, which is an ecotonal species.","PeriodicalId":55408,"journal":{"name":"Avian Biology Research","volume":"15 1","pages":"180 - 193"},"PeriodicalIF":0.6,"publicationDate":"2022-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47254901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-09DOI: 10.1177/17581559221125364
Zong-zhi Li, Bo Pang, Zhi-cheng Yao, Shuhui Mi, Zhen-sheng Liu, Li-wei Teng
Habitat degradation and fragmentation are crucial factors which result in biodiversity loss among the world. Understanding how species respond to the habitat change is helpful and essential for the conservation of the endangered ones. Therefore, the aim of current study is to explore how to carry out biodiversity conservation from the perspective of the habitat selection of species. We studied the microhabitat selection of blue eared pheasant (Crossoptilon auritum) during its breeding time (including mating, incubation, and feeding periods). The field research was carried out from April to August in 2014 at Helan Mountains, China. Six nests of blue eared pheasants were found; 323 used plots and 171 control plots were recorded. Results indicated that blue eared pheasants prefer mountainous coniferous forest at shady slope with domination of Picea crassifolia, and its habitat selection was mainly influenced by shrub density, tree density, altitude, slope degree, hiding cover, water resource, and human disturbance. However, there were slight differences among the three periods. Our study firstly compared factors that affect the microhabitat selection of blue eared pheasants among the three periods of its breeding time. Meanwhile, combining the current study with the previous ones, specific strategies could be applied on the works of endangered species and biodiversity conservation.
{"title":"Microhabitat selection of blue eared pheasant (Crossoptilon auritum) during breeding period in Helan Mountains, China","authors":"Zong-zhi Li, Bo Pang, Zhi-cheng Yao, Shuhui Mi, Zhen-sheng Liu, Li-wei Teng","doi":"10.1177/17581559221125364","DOIUrl":"https://doi.org/10.1177/17581559221125364","url":null,"abstract":"Habitat degradation and fragmentation are crucial factors which result in biodiversity loss among the world. Understanding how species respond to the habitat change is helpful and essential for the conservation of the endangered ones. Therefore, the aim of current study is to explore how to carry out biodiversity conservation from the perspective of the habitat selection of species. We studied the microhabitat selection of blue eared pheasant (Crossoptilon auritum) during its breeding time (including mating, incubation, and feeding periods). The field research was carried out from April to August in 2014 at Helan Mountains, China. Six nests of blue eared pheasants were found; 323 used plots and 171 control plots were recorded. Results indicated that blue eared pheasants prefer mountainous coniferous forest at shady slope with domination of Picea crassifolia, and its habitat selection was mainly influenced by shrub density, tree density, altitude, slope degree, hiding cover, water resource, and human disturbance. However, there were slight differences among the three periods. Our study firstly compared factors that affect the microhabitat selection of blue eared pheasants among the three periods of its breeding time. Meanwhile, combining the current study with the previous ones, specific strategies could be applied on the works of endangered species and biodiversity conservation.","PeriodicalId":55408,"journal":{"name":"Avian Biology Research","volume":"15 1","pages":"173 - 179"},"PeriodicalIF":0.6,"publicationDate":"2022-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49416752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-27DOI: 10.1177/17581559221121712
James M. Gresh, J. Courter
Over the last half-century, North American forest birds have experienced staggering declines, while at the same time, many metrics indicate that North American forest health has improved. While the United States has been recognised for global leadership in innovation and research in forestry, the negative impacts of high-severity harvesting methods and forest fragmentation are sometimes overlooked, and a dearth of research studies exist that assess the impacts of lower-severity forestry practices on birds. Globally, some regions are pursuing markedly different forestry practices, and one example is Europe’s Close-To-Nature Forestry (CTNF) that protects forest canopies. Historically, CTNF methods have not been promoted to help avian abundance or diversity; however, forest bird populations in Europe have increased 7% over the last two decades, and we posit whether similar forest management approaches in the eastern USA could benefit North American birds. Therefore, we sought to 1) assess the effects of forest structural characteristics on avian species richness in a CTNF-managed forest in the eastern USA; 2) compare our results to county-level eBird data to identify the challenges of assessing the impacts of forestry practices on birds at landscape scales; 3) highlight the ambiguities in current forest management guidelines for improving avian habitats in the USA and 4) suggest long-term direction for evaluating the impacts of alternative forest management practices on birds. Our case study provides preliminary evidence that CTNF-managed forests may support diverse birds of high conservation value that are normally drawn to different forest management extremes. We also provide recommendations for utilising eBird data to assess alternative forest management strategies at landscape scales and a synthesised look at the forest management guidelines provided by many of the major players in American ornithology. While there may be multiple reasons for forest bird declines noted in the past 50 years in North America, long-standing forest management practices and policies should not be overlooked.
{"title":"Assessing the effects of Close-to-Nature Forestry on forest birds in the eastern United States: A case study and way forward","authors":"James M. Gresh, J. Courter","doi":"10.1177/17581559221121712","DOIUrl":"https://doi.org/10.1177/17581559221121712","url":null,"abstract":"Over the last half-century, North American forest birds have experienced staggering declines, while at the same time, many metrics indicate that North American forest health has improved. While the United States has been recognised for global leadership in innovation and research in forestry, the negative impacts of high-severity harvesting methods and forest fragmentation are sometimes overlooked, and a dearth of research studies exist that assess the impacts of lower-severity forestry practices on birds. Globally, some regions are pursuing markedly different forestry practices, and one example is Europe’s Close-To-Nature Forestry (CTNF) that protects forest canopies. Historically, CTNF methods have not been promoted to help avian abundance or diversity; however, forest bird populations in Europe have increased 7% over the last two decades, and we posit whether similar forest management approaches in the eastern USA could benefit North American birds. Therefore, we sought to 1) assess the effects of forest structural characteristics on avian species richness in a CTNF-managed forest in the eastern USA; 2) compare our results to county-level eBird data to identify the challenges of assessing the impacts of forestry practices on birds at landscape scales; 3) highlight the ambiguities in current forest management guidelines for improving avian habitats in the USA and 4) suggest long-term direction for evaluating the impacts of alternative forest management practices on birds. Our case study provides preliminary evidence that CTNF-managed forests may support diverse birds of high conservation value that are normally drawn to different forest management extremes. We also provide recommendations for utilising eBird data to assess alternative forest management strategies at landscape scales and a synthesised look at the forest management guidelines provided by many of the major players in American ornithology. While there may be multiple reasons for forest bird declines noted in the past 50 years in North America, long-standing forest management practices and policies should not be overlooked.","PeriodicalId":55408,"journal":{"name":"Avian Biology Research","volume":"15 1","pages":"161 - 172"},"PeriodicalIF":0.6,"publicationDate":"2022-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46890552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-14DOI: 10.1177/17581559221113641
Rubén Ortega‐Álvarez, Rafael Calderón-Parra, Fernando García-Luna
Feeding research is relevant to comprehend wildlife use of urban systems and to guide management practices. Coupling foraging with habitat assessments is important because environmental conditions affect animal access to food, leading to variations in behaviours and the numbers of feeding individuals. Still, we have little comprehension about the foraging ecology of animals in Neotropical cities. We analyzed the feeding use of an urban mega-park by a migratory bird in Mexico City, central Mexico. We used distance sampling and hierarchical models to identify the habitat traits that determined the feeding density of the Yellow-rumped (Audubon’s) Warbler (Setophaga coronata auduboni) in the Chapultepec mega-park. Moreover, we evaluated the spatial variation of the feeding behavior of the species across the site and compared the substrates that this warbler used for foraging by utilizing a Bayesian modelling approach. We included observations from a grey area adjacent to the mega-park for comparison purposes. Our results demonstrated that the number of feeding individuals of the Yellow-rumped Warbler was determined by tree species richness and the number of pedestrians. Greater numbers of tree species might foster the diversity and availability of food resources for the warbler, whereas the number of pedestrians might increase risk perception by birds, reducing their foraging activity. The variation in the proportion of feeding occasions among the sections of Chapultepec supported the pattern associated with our feeding density analysis. The species fed most frequently on trees than in any other substrate. Thus, we showed that urban green areas provide important feeding grounds for the Yellow-rumped Warbler during the migratory period, particularly where tree species richness increases and human activity reduces. Management and restoration activities across the mega-park should be directed to foster tree species richness and mitigate the impact of human activities to enhance the feeding activity of migratory birds.
{"title":"Trees and people determine the feeding activity of a migratory bird in an urban mega-park of Mexico city","authors":"Rubén Ortega‐Álvarez, Rafael Calderón-Parra, Fernando García-Luna","doi":"10.1177/17581559221113641","DOIUrl":"https://doi.org/10.1177/17581559221113641","url":null,"abstract":"Feeding research is relevant to comprehend wildlife use of urban systems and to guide management practices. Coupling foraging with habitat assessments is important because environmental conditions affect animal access to food, leading to variations in behaviours and the numbers of feeding individuals. Still, we have little comprehension about the foraging ecology of animals in Neotropical cities. We analyzed the feeding use of an urban mega-park by a migratory bird in Mexico City, central Mexico. We used distance sampling and hierarchical models to identify the habitat traits that determined the feeding density of the Yellow-rumped (Audubon’s) Warbler (Setophaga coronata auduboni) in the Chapultepec mega-park. Moreover, we evaluated the spatial variation of the feeding behavior of the species across the site and compared the substrates that this warbler used for foraging by utilizing a Bayesian modelling approach. We included observations from a grey area adjacent to the mega-park for comparison purposes. Our results demonstrated that the number of feeding individuals of the Yellow-rumped Warbler was determined by tree species richness and the number of pedestrians. Greater numbers of tree species might foster the diversity and availability of food resources for the warbler, whereas the number of pedestrians might increase risk perception by birds, reducing their foraging activity. The variation in the proportion of feeding occasions among the sections of Chapultepec supported the pattern associated with our feeding density analysis. The species fed most frequently on trees than in any other substrate. Thus, we showed that urban green areas provide important feeding grounds for the Yellow-rumped Warbler during the migratory period, particularly where tree species richness increases and human activity reduces. Management and restoration activities across the mega-park should be directed to foster tree species richness and mitigate the impact of human activities to enhance the feeding activity of migratory birds.","PeriodicalId":55408,"journal":{"name":"Avian Biology Research","volume":"15 1","pages":"149 - 157"},"PeriodicalIF":0.6,"publicationDate":"2022-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42278418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-28DOI: 10.1177/17581559221111687
S. M. Amininasab, S. M. Hosseini-Moosavi, Charles C. Y. Xu
Understanding the factors that influence avian reproductive output is critical for bird conservation as they reveal key considerations that directly impact a species’ long term survival and should be integrated into management plans. To better this understanding for the little bittern Ixobrychus minutus, we investigated how their breeding success relates to breeding time, nest size, water depth, and egg size in a man-made wetland (Ab-bandan) during the 2008 breeding season in Mazandaran Province, northern Iran. For each nest, the dates of the first egg laying, the first hatching, and the first fledging were recorded as well as clutch sizes. Nest size parameters (height, depth, and diameter), water depth under the nest, and egg characteristics (shape index and weight) were measured. The first egg was laid on March 21 and the last chick left the nest on June 24. From 140 eggs in 25 nests, 127 eggs hatched (91%) and 121 fledglings left their nests (87%). Generalized linear modeling revealed that nest diameter positively affected breeding success (p = 0.001) meaning larger nests were more likely to produce fledglings. Further studies will be necessary to elucidate the underlying mechanisms.
{"title":"Influence of breeding time, nest size, water depth, and egg size on the breeding success of the little bittern Ixobrychus minutus","authors":"S. M. Amininasab, S. M. Hosseini-Moosavi, Charles C. Y. Xu","doi":"10.1177/17581559221111687","DOIUrl":"https://doi.org/10.1177/17581559221111687","url":null,"abstract":"Understanding the factors that influence avian reproductive output is critical for bird conservation as they reveal key considerations that directly impact a species’ long term survival and should be integrated into management plans. To better this understanding for the little bittern Ixobrychus minutus, we investigated how their breeding success relates to breeding time, nest size, water depth, and egg size in a man-made wetland (Ab-bandan) during the 2008 breeding season in Mazandaran Province, northern Iran. For each nest, the dates of the first egg laying, the first hatching, and the first fledging were recorded as well as clutch sizes. Nest size parameters (height, depth, and diameter), water depth under the nest, and egg characteristics (shape index and weight) were measured. The first egg was laid on March 21 and the last chick left the nest on June 24. From 140 eggs in 25 nests, 127 eggs hatched (91%) and 121 fledglings left their nests (87%). Generalized linear modeling revealed that nest diameter positively affected breeding success (p = 0.001) meaning larger nests were more likely to produce fledglings. Further studies will be necessary to elucidate the underlying mechanisms.","PeriodicalId":55408,"journal":{"name":"Avian Biology Research","volume":"15 1","pages":"144 - 148"},"PeriodicalIF":0.6,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44651861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-23DOI: 10.1177/17581559221110107
D. A. Erastova, J. A. Galbraith, K. Cain, Y. van Heezik, E. Hume, M. Stanley
Garden bird sugar water feeding is increasingly popular worldwide, but little is known about its effects on bird health and associated diseases. There is a concern that feeding stations can accumulate pathogens and facilitate pathogen transmission between individuals, resulting in adverse effects on body condition of visiting birds. We tested the effects of sugar water feeding in urban New Zealand backyards by sampling target species for multiple infections and comparing bird body condition. For this, we compared backyards with and without sugar water feeders and again compared existing sugar water feeders with various sugar concentrations in two cities and in two seasons. Birds caught in gardens with sugar water feeders had poorer body condition; however, birds had better body condition in the city with the warmer climate (Auckland), during summer, and in gardens with high (≥20%) sugar concentration in sugar water feeders in winter. All screening tests for Chlamydia psittaci and Salmonella spp. returned negative results. Avian poxvirus prevalence in tauhou (Zosterops lateralis) was four times higher in the city with a warmer climate. The likelihood of lice infection in tauhou was lower in gardens with feeders, in the warmer city, in summer, and at feeders with higher sugar concentrations. In tūī (Prosthemadera novaeseelandiae), the likelihood of lice infection decreased with an increase in sugar concentration. Coccidia infection was 4.25 times higher in tauhou in gardens with feeders. Despite the identified risks associated with sugar water feeding, there appear to be potential benefits for native nectarivorous birds, specifically in winter.
{"title":"Effects of urban sugar water feeding on bird body condition and avian diseases","authors":"D. A. Erastova, J. A. Galbraith, K. Cain, Y. van Heezik, E. Hume, M. Stanley","doi":"10.1177/17581559221110107","DOIUrl":"https://doi.org/10.1177/17581559221110107","url":null,"abstract":"Garden bird sugar water feeding is increasingly popular worldwide, but little is known about its effects on bird health and associated diseases. There is a concern that feeding stations can accumulate pathogens and facilitate pathogen transmission between individuals, resulting in adverse effects on body condition of visiting birds. We tested the effects of sugar water feeding in urban New Zealand backyards by sampling target species for multiple infections and comparing bird body condition. For this, we compared backyards with and without sugar water feeders and again compared existing sugar water feeders with various sugar concentrations in two cities and in two seasons. Birds caught in gardens with sugar water feeders had poorer body condition; however, birds had better body condition in the city with the warmer climate (Auckland), during summer, and in gardens with high (≥20%) sugar concentration in sugar water feeders in winter. All screening tests for Chlamydia psittaci and Salmonella spp. returned negative results. Avian poxvirus prevalence in tauhou (Zosterops lateralis) was four times higher in the city with a warmer climate. The likelihood of lice infection in tauhou was lower in gardens with feeders, in the warmer city, in summer, and at feeders with higher sugar concentrations. In tūī (Prosthemadera novaeseelandiae), the likelihood of lice infection decreased with an increase in sugar concentration. Coccidia infection was 4.25 times higher in tauhou in gardens with feeders. Despite the identified risks associated with sugar water feeding, there appear to be potential benefits for native nectarivorous birds, specifically in winter.","PeriodicalId":55408,"journal":{"name":"Avian Biology Research","volume":"15 1","pages":"133 - 143"},"PeriodicalIF":0.6,"publicationDate":"2022-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46487858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-06DOI: 10.1177/17581559221107083
L. Rozsypalová, D. Rymešová, Petr Stýblo, I. Literák
Admission records from wildlife rescue centres can help identify causes of morbidity for species of conservation concern, and to assess the effectiveness of rehabilitation. This study documents the causes of admission and outcomes of treatment in 68 white-tailed eagles admitted to rescue centres in the Czech Republic. We determine the factors that contribute to the outcome of rehabilitation. Most admitted birds were juveniles (1st calendar year [CY]; n = 25), followed by immatures (2nd–4th CY; n = 23) and adults (≥5 CY; n = 17). We categorised admission causes into (1) trauma-related cases (most often unknown trauma, followed by collision and intraspecific fights), (2) non-trauma cases (weakness, toxicosis and becoming stuck in mud or entangled in rope) and (3) orphaned young birds. Trauma-related admissions were most numerous totalling 59%, non-trauma admissions accounted for 35% with the remaining 6% comprising orphaned young birds. At least a third of eagle admissions were caused by anthropogenic factors. In total, 40% of admitted eagles were released back to the wild, 35% died or were euthanized and 25% remained permanently in captivity. Eagles admitted due to non-trauma-related causes had a significantly higher probability of being released into the wild than those admitted due to trauma. Immature eagles were less likely to be released than juvenile individuals. Admissions data are valuable for conservation research, allowing for trends in threats towards species of conservation concern to be quantified, over time, throughout human-dominated landscapes.
{"title":"Causes of admission and outcomes of white-tailed eagles Haliaeetus albicilla in wildlife rescue centres in the Czech Republic during 2010–2020","authors":"L. Rozsypalová, D. Rymešová, Petr Stýblo, I. Literák","doi":"10.1177/17581559221107083","DOIUrl":"https://doi.org/10.1177/17581559221107083","url":null,"abstract":"Admission records from wildlife rescue centres can help identify causes of morbidity for species of conservation concern, and to assess the effectiveness of rehabilitation. This study documents the causes of admission and outcomes of treatment in 68 white-tailed eagles admitted to rescue centres in the Czech Republic. We determine the factors that contribute to the outcome of rehabilitation. Most admitted birds were juveniles (1st calendar year [CY]; n = 25), followed by immatures (2nd–4th CY; n = 23) and adults (≥5 CY; n = 17). We categorised admission causes into (1) trauma-related cases (most often unknown trauma, followed by collision and intraspecific fights), (2) non-trauma cases (weakness, toxicosis and becoming stuck in mud or entangled in rope) and (3) orphaned young birds. Trauma-related admissions were most numerous totalling 59%, non-trauma admissions accounted for 35% with the remaining 6% comprising orphaned young birds. At least a third of eagle admissions were caused by anthropogenic factors. In total, 40% of admitted eagles were released back to the wild, 35% died or were euthanized and 25% remained permanently in captivity. Eagles admitted due to non-trauma-related causes had a significantly higher probability of being released into the wild than those admitted due to trauma. Immature eagles were less likely to be released than juvenile individuals. Admissions data are valuable for conservation research, allowing for trends in threats towards species of conservation concern to be quantified, over time, throughout human-dominated landscapes.","PeriodicalId":55408,"journal":{"name":"Avian Biology Research","volume":"15 1","pages":"125 - 132"},"PeriodicalIF":0.6,"publicationDate":"2022-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47856703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-03DOI: 10.1177/17581559221097269
A. Guaraldo, Juliane Coimbra Bczuska, L. Manica
Few studies on bird migration address altitudinal migration in South America, a regional-scale movement currently known for only nine species within the threatened Atlantic Forest biome. The Yellow-legged Thrush Turdus flavipes (YLTH) is one of such migrants thus far studied within a narrow altitudinal gradient and for which only fruits are pointed as the likely triggers of its seasonal movements. Here, we expand this knowledge by testing the hypotheses that arthropod and fleshy fruit availabilities, and climatic variables may all play roles in the seasonal abundance of this species along a broader altitudinal gradient (10-1,100 m asl) in the Atlantic Forest. We estimated YLTH density and its food resource availability in sites at three different altitudes. Besides supporting previous findings on the YLTH migratory behaviour, our findings reveal a novel and complex seasonal density variation of the species across altitudes, consistent with a partial altitudinal migration from higher altitudes. Aside from fruit availability, rainfall also partially influenced such behaviour, a new perspective for this species. Besides providing a broader picture for the altitudinal migration of YLTHs, we conclude by stressing the need for further studies on the understudied altitudinal migration system of birds within South America, including the assessment of the general validity of current hypotheses on the mechanisms underlying this interesting behaviour and its evolution.
很少有关于鸟类迁徙的研究涉及南美洲的海拔迁徙，这是一种区域性的迁徙，目前已知在受威胁的大西洋森林生物群落中只有九个物种。黄腿画眉（YLTH）是迄今为止在狭窄的海拔梯度内研究的迁徙动物之一，只有水果可能是其季节性运动的触发因素。在这里，我们通过测试以下假设来扩展这一知识，即节肢动物和肉质水果的可利用性以及气候变量都可能在大西洋森林中沿着更宽的海拔梯度（10-1100 m asl）的该物种的季节性丰度中发挥作用。我们估计了三个不同海拔地区的YLTH密度及其食物资源可用性。除了支持之前关于YLTH迁徙行为的研究结果外，我们的研究结果还揭示了物种在不同海拔高度的新的复杂季节密度变化，与从较高海拔高度的部分海拔迁徙一致。除了水果的供应，降雨也部分影响了这种行为，这为该物种提供了一个新的视角。除了为YLTH的高度迁徙提供更广泛的信息外，我们还强调有必要对南美洲鸟类的高度迁徙系统进行进一步研究，包括评估目前关于这种有趣行为及其进化机制的假设的总体有效性。
{"title":"Turdus flavipes altitudinal migration in the Atlantic Forest The Yellow-legged Thrush is a partial altitudinal migrant in the Atlantic Forest","authors":"A. Guaraldo, Juliane Coimbra Bczuska, L. Manica","doi":"10.1177/17581559221097269","DOIUrl":"https://doi.org/10.1177/17581559221097269","url":null,"abstract":"Few studies on bird migration address altitudinal migration in South America, a regional-scale movement currently known for only nine species within the threatened Atlantic Forest biome. The Yellow-legged Thrush Turdus flavipes (YLTH) is one of such migrants thus far studied within a narrow altitudinal gradient and for which only fruits are pointed as the likely triggers of its seasonal movements. Here, we expand this knowledge by testing the hypotheses that arthropod and fleshy fruit availabilities, and climatic variables may all play roles in the seasonal abundance of this species along a broader altitudinal gradient (10-1,100 m asl) in the Atlantic Forest. We estimated YLTH density and its food resource availability in sites at three different altitudes. Besides supporting previous findings on the YLTH migratory behaviour, our findings reveal a novel and complex seasonal density variation of the species across altitudes, consistent with a partial altitudinal migration from higher altitudes. Aside from fruit availability, rainfall also partially influenced such behaviour, a new perspective for this species. Besides providing a broader picture for the altitudinal migration of YLTHs, we conclude by stressing the need for further studies on the understudied altitudinal migration system of birds within South America, including the assessment of the general validity of current hypotheses on the mechanisms underlying this interesting behaviour and its evolution.","PeriodicalId":55408,"journal":{"name":"Avian Biology Research","volume":"15 1","pages":"117 - 124"},"PeriodicalIF":0.6,"publicationDate":"2022-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41738106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-01DOI: 10.1177/17581559221092692
G. Ritchison, Lauren C. Lewis, C. Heist
The unique predatory, caching, and impaling behaviors of shrikes (Laniidae) may provide these unusual passerines with alternative provisioning strategies compared to other songbirds, but few studies have determined the impact these unique behaviors have on provisioning rates. Our objectives were to compare the provisioning behavior of male and female Loggerhead Shrikes (Lanius ludovicianus), and determine how their provisioning behavior was influenced by nestling age. The provisioning behavior of six pairs of Loggerhead Shrikes was videotaped from 15 April to 15 August 2004–2007 in Garrard and Madison counties, Kentucky, USA. For each nest visit by a shrike, the sex of the visiting adult, number of prey items delivered, size of prey, type of prey, and the duration of the nest visit were recorded. Adults made 2169 visits to nests, with males (49%) and females (51%) making similar numbers of visits. Males and females differed in time spent at nests, with males spending less time at nests per visit (mean = 12.0 s, N = 1062) than females (77.0 s, N = 1107). Feeding rates did not differ between the sexes, but feeding rates did increase with nestling age. The size of prey delivered to nestlings also tended to increase with nestling age. Invertebrates comprised 65% of the identified prey items, and cached items made up the remaining 35%. Although many passerine species increase provisioning rates as nestling demand increases, the caching behavior of shrikes may allow adults to reliably increase both feeding rates and prey size as nestling age and demand increase as well as act as buffers when prey availability declines. The caching behavior of shrikes provides them with parental provisioning strategies not available to non-caching songbirds.
{"title":"Provisioning behavior of male and female Loggerhead Shrikes","authors":"G. Ritchison, Lauren C. Lewis, C. Heist","doi":"10.1177/17581559221092692","DOIUrl":"https://doi.org/10.1177/17581559221092692","url":null,"abstract":"The unique predatory, caching, and impaling behaviors of shrikes (Laniidae) may provide these unusual passerines with alternative provisioning strategies compared to other songbirds, but few studies have determined the impact these unique behaviors have on provisioning rates. Our objectives were to compare the provisioning behavior of male and female Loggerhead Shrikes (Lanius ludovicianus), and determine how their provisioning behavior was influenced by nestling age. The provisioning behavior of six pairs of Loggerhead Shrikes was videotaped from 15 April to 15 August 2004–2007 in Garrard and Madison counties, Kentucky, USA. For each nest visit by a shrike, the sex of the visiting adult, number of prey items delivered, size of prey, type of prey, and the duration of the nest visit were recorded. Adults made 2169 visits to nests, with males (49%) and females (51%) making similar numbers of visits. Males and females differed in time spent at nests, with males spending less time at nests per visit (mean = 12.0 s, N = 1062) than females (77.0 s, N = 1107). Feeding rates did not differ between the sexes, but feeding rates did increase with nestling age. The size of prey delivered to nestlings also tended to increase with nestling age. Invertebrates comprised 65% of the identified prey items, and cached items made up the remaining 35%. Although many passerine species increase provisioning rates as nestling demand increases, the caching behavior of shrikes may allow adults to reliably increase both feeding rates and prey size as nestling age and demand increase as well as act as buffers when prey availability declines. The caching behavior of shrikes provides them with parental provisioning strategies not available to non-caching songbirds.","PeriodicalId":55408,"journal":{"name":"Avian Biology Research","volume":"15 1","pages":"93 - 99"},"PeriodicalIF":0.6,"publicationDate":"2022-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46298396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-08DOI: 10.1177/17581559221092642
Angelica N Reed, S. B. McRae
Considerable within-population variation in nest size exists among cavity nesters. We sought to explain this by studying a multi-brooded population of Eastern Bluebirds (Sialia sialis) breeding in nest boxes. We examined seasonal change in nest weights and compared the weights of nests built by immigrant and resident females. We further investigated whether nest weight correlated with maternal condition or breeding success. Nest weight measured after broods fledged was correlated with nest height at the start of incubation. Breeders spent fewer days building and built successively smaller, lighter nests in later nesting attempts. Female bluebirds performed the majority of nest construction. Nests built by immigrant females were significantly larger on average than those built by female recruits hatched on site, and the seasonal decline in nest weight was more pronounced for natally philopatric females. For the first time, we present evidence that the weights of philopatric females’ first nests were significantly positively correlated with the weights of the nests they were raised in, suggesting an effect of natal memory. Contrary to expectation, neither maternal condition nor reproductive success (clutch size, hatching success, brood size, and fledging success) was related to nest weight. To investigate whether smaller nests provided a thermal advantage in summer nest attempts when afternoon box temperatures can exceed 41°C, we measured the temperature within nest boxes using programmable data loggers. Mean daily maximum box temperatures during incubation were significantly positively related to nest weight and significantly negatively related to the volume of free space above the nest. Increased air circulation above the nest likely contributed to cooling the boxes when ambient temperatures were high. Reducing nest size was therefore advantageous, especially in later nesting attempts when ambient temperatures were warmest. Seasonal decline in nest weights and differences between immigrant and natally philopatric females merits further investigation.
{"title":"Natal philopatry is associated with smaller nest size in a cavity-nesting bird with consequences for nest box temperature","authors":"Angelica N Reed, S. B. McRae","doi":"10.1177/17581559221092642","DOIUrl":"https://doi.org/10.1177/17581559221092642","url":null,"abstract":"Considerable within-population variation in nest size exists among cavity nesters. We sought to explain this by studying a multi-brooded population of Eastern Bluebirds (Sialia sialis) breeding in nest boxes. We examined seasonal change in nest weights and compared the weights of nests built by immigrant and resident females. We further investigated whether nest weight correlated with maternal condition or breeding success. Nest weight measured after broods fledged was correlated with nest height at the start of incubation. Breeders spent fewer days building and built successively smaller, lighter nests in later nesting attempts. Female bluebirds performed the majority of nest construction. Nests built by immigrant females were significantly larger on average than those built by female recruits hatched on site, and the seasonal decline in nest weight was more pronounced for natally philopatric females. For the first time, we present evidence that the weights of philopatric females’ first nests were significantly positively correlated with the weights of the nests they were raised in, suggesting an effect of natal memory. Contrary to expectation, neither maternal condition nor reproductive success (clutch size, hatching success, brood size, and fledging success) was related to nest weight. To investigate whether smaller nests provided a thermal advantage in summer nest attempts when afternoon box temperatures can exceed 41°C, we measured the temperature within nest boxes using programmable data loggers. Mean daily maximum box temperatures during incubation were significantly positively related to nest weight and significantly negatively related to the volume of free space above the nest. Increased air circulation above the nest likely contributed to cooling the boxes when ambient temperatures were high. Reducing nest size was therefore advantageous, especially in later nesting attempts when ambient temperatures were warmest. Seasonal decline in nest weights and differences between immigrant and natally philopatric females merits further investigation.","PeriodicalId":55408,"journal":{"name":"Avian Biology Research","volume":"15 1","pages":"100 - 112"},"PeriodicalIF":0.6,"publicationDate":"2022-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48296105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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