Flexibility in migratory behaviour may have significant consequences for the adaptability of birds to ongoing environmental changes. Shifts in arrival and departure dates, migration distance and even direction of migration have all been demonstrated over the last few decades in a variety of species, mostly passerines. Less well understood is the spatio-temporal dynamics of migration at so-called migratory divides, i.e. contact zones of populations with different migratory strategies. We used data on 58 White Storks Ciconia ciconia ringed as nestlings in a part of the Central European migratory divide in the Czech Republic during the period 1947–2018 and recovered during their first winter season in October to February, to test the hypotheses of (1) shortening migratory distance over the years and (2) a shift in the proportion of adopted migratory strategies being a proximate factor of changes in migration distance. Using regression analysis, we provided evidence of gradual linear decrease over the years in mean recovery distance of ringed nestlings during their first winter. Results of multinomial regression analysis showed that this decrease has been proximately driven by an increase in the proportion of storks recovered within 500 km from their natal site, a decreasing proportion of storks recovered on the eastern migratory flyway and an increasing proportion of storks recovered on the western migratory flyway. Evidence for Czech Storks migrating via the western migratory flyway first appeared in 2003. The apparent shift of young Storks to migrate via the western flyway from the Czech Republic is most likely a result of immigration by individuals from growing western populations. This leads to diluting of populations migrating via the eastern flyway with migrants using the western flyway. Our study provides evidence that behavioural flexibility may drive dynamics of migration at the migratory divide, with changes of similar magnitudes as those driven by genetic change, as reported in passerines.
{"title":"Dynamics of Naïve White Storks Ciconia Ciconia Migrating at the Central European Migratory Divide during 1947–2018","authors":"J. Hušek, P. Klvaňa, J. Cepák","doi":"10.5253/arde.2022.a15","DOIUrl":"https://doi.org/10.5253/arde.2022.a15","url":null,"abstract":"Flexibility in migratory behaviour may have significant consequences for the adaptability of birds to ongoing environmental changes. Shifts in arrival and departure dates, migration distance and even direction of migration have all been demonstrated over the last few decades in a variety of species, mostly passerines. Less well understood is the spatio-temporal dynamics of migration at so-called migratory divides, i.e. contact zones of populations with different migratory strategies. We used data on 58 White Storks Ciconia ciconia ringed as nestlings in a part of the Central European migratory divide in the Czech Republic during the period 1947–2018 and recovered during their first winter season in October to February, to test the hypotheses of (1) shortening migratory distance over the years and (2) a shift in the proportion of adopted migratory strategies being a proximate factor of changes in migration distance. Using regression analysis, we provided evidence of gradual linear decrease over the years in mean recovery distance of ringed nestlings during their first winter. Results of multinomial regression analysis showed that this decrease has been proximately driven by an increase in the proportion of storks recovered within 500 km from their natal site, a decreasing proportion of storks recovered on the eastern migratory flyway and an increasing proportion of storks recovered on the western migratory flyway. Evidence for Czech Storks migrating via the western migratory flyway first appeared in 2003. The apparent shift of young Storks to migrate via the western flyway from the Czech Republic is most likely a result of immigration by individuals from growing western populations. This leads to diluting of populations migrating via the eastern flyway with migrants using the western flyway. Our study provides evidence that behavioural flexibility may drive dynamics of migration at the migratory divide, with changes of similar magnitudes as those driven by genetic change, as reported in passerines.","PeriodicalId":55463,"journal":{"name":"Ardea","volume":" ","pages":"1 - 10"},"PeriodicalIF":0.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44435204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Prey resources in oligotrophic tropical marine environments are often scattered and unpredictable. Tracking studies of tropical seabirds can provide critical information about ocean habitat affinities, prey choice and the utilisation of surrounding areas, which can be useful for conservation managers. Foraging studies of Red-billed Tropicbird populations in the Caribbean are scarce but increasing. We sought to expand on this by tracking chick-rearing adults using GPS devices and subsequently linking these tracking data to remotely-sensed environmental variables. We related our spatial data to opportunistic sampling of regurgitates in a globally significant nesting colony on Saba, Caribbean Netherlands. Diet samples were dominated by flying fish (Exocoetidae; numerical frequency: 70.73%), but prey items from the squid family (Loliginidae; 9.76%) and the families of flying gurnards (Dactylopteridae; 2.44%) and the ray-finned fish (Carangidae; 2.44%) were also identified, although we were unable to identify 14.63% of samples due to digestion. An additional goal of our study was to compare the foraging ecology of Tropicbirds on Saba with those nesting on St. Eustatius, located circa 25 km south-east. As expected, Tropicbirds nesting on Saba exhibited diurnal foraging patterns, travelling a maximum distance from the colony of 553.7 km, with an average trip length of 117.2 ± 144.6 km (±SD). Adults foraged in shallower, cooler waters with higher chlorophyll a concentrations and higher Exocoetidae species richness compared to travelling points. Despite the proximity of Saba and St. Eustatius, this is contrary to what was found for Tropicbirds nesting on St. Eustatius, where adults foraged in deeper waters with a low Exocoetidae species richness. However, Tropicbirds from Saba and St. Eustatius did exhibit some similarities in their foraging behaviour; specifically, foraging adults traversed multiple exclusive economic zones and marine protected areas, reinforcing our recommendation for nature managers in the Caribbean to create a transboundary network in order to effectively protect and conserve this species.
{"title":"Foraging Ecology of Red-Billed Tropicbirds on Saba, Caribbean Netherlands, during Early Chick-Rearing","authors":"H. Madden, Helena Boehm, L. Mielke","doi":"10.5253/arde.2022.a14","DOIUrl":"https://doi.org/10.5253/arde.2022.a14","url":null,"abstract":"Prey resources in oligotrophic tropical marine environments are often scattered and unpredictable. Tracking studies of tropical seabirds can provide critical information about ocean habitat affinities, prey choice and the utilisation of surrounding areas, which can be useful for conservation managers. Foraging studies of Red-billed Tropicbird populations in the Caribbean are scarce but increasing. We sought to expand on this by tracking chick-rearing adults using GPS devices and subsequently linking these tracking data to remotely-sensed environmental variables. We related our spatial data to opportunistic sampling of regurgitates in a globally significant nesting colony on Saba, Caribbean Netherlands. Diet samples were dominated by flying fish (Exocoetidae; numerical frequency: 70.73%), but prey items from the squid family (Loliginidae; 9.76%) and the families of flying gurnards (Dactylopteridae; 2.44%) and the ray-finned fish (Carangidae; 2.44%) were also identified, although we were unable to identify 14.63% of samples due to digestion. An additional goal of our study was to compare the foraging ecology of Tropicbirds on Saba with those nesting on St. Eustatius, located circa 25 km south-east. As expected, Tropicbirds nesting on Saba exhibited diurnal foraging patterns, travelling a maximum distance from the colony of 553.7 km, with an average trip length of 117.2 ± 144.6 km (±SD). Adults foraged in shallower, cooler waters with higher chlorophyll a concentrations and higher Exocoetidae species richness compared to travelling points. Despite the proximity of Saba and St. Eustatius, this is contrary to what was found for Tropicbirds nesting on St. Eustatius, where adults foraged in deeper waters with a low Exocoetidae species richness. However, Tropicbirds from Saba and St. Eustatius did exhibit some similarities in their foraging behaviour; specifically, foraging adults traversed multiple exclusive economic zones and marine protected areas, reinforcing our recommendation for nature managers in the Caribbean to create a transboundary network in order to effectively protect and conserve this species.","PeriodicalId":55463,"journal":{"name":"Ardea","volume":"111 1","pages":"1 - 18"},"PeriodicalIF":0.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47702072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Conservation status assessment of bird species is essential to prioritize conservation and monitoring efforts; however, this is not always possible to achieve due to lack of field data or scientific knowledge. In this context citizen science platforms can act as a data source to prioritize the conservation and research resources within a region or a given taxonomic group. Merging the available information on bird distribution areas from BirdLife International and field observations from eBird, the main citizen science birding app, we create a concern index, using the poorly known buttonquails (Turnicidae) as a case study. This concern index is based on two parameters: scarcity and uncertainty, which ultimately are based on two components, respectively. For every species, we defined scarcity as a combination of its frequency of occurrence (proportion of positive eBird checklists) and its relative range size, while uncertainty is a combination of the eBird effort (density of eBird checklists) and the range accuracy (proportion of positive eBird checklists within the BirdLife distribution area). We found a high correlation (Spearman r = 0.74) between our concern index and the IUCN threat categories for all buttonquail species. Then we apply this concern index to all buttonquail subspecies obtaining a ranked list for these non-assessed taxa, with some island endemic subspecies ranking very high together with the most endangered buttonquail species. Our approach is a very simple method to rank species within a given bird group and prioritize monitoring and conservation efforts. Moreover, it is also suitable for other taxonomic levels as subspecies or even for ecological units as populations, which normally lack a formal conservation status assessment.
{"title":"Prioritizing Conservation and Research Effort for Poorly Known Species: The Buttonquails (Turnicidae) as a Study Case","authors":"C. Gutiérrez‐Expósito, M. Clavero, E. Revilla","doi":"10.5253/arde.2022.a33","DOIUrl":"https://doi.org/10.5253/arde.2022.a33","url":null,"abstract":"Conservation status assessment of bird species is essential to prioritize conservation and monitoring efforts; however, this is not always possible to achieve due to lack of field data or scientific knowledge. In this context citizen science platforms can act as a data source to prioritize the conservation and research resources within a region or a given taxonomic group. Merging the available information on bird distribution areas from BirdLife International and field observations from eBird, the main citizen science birding app, we create a concern index, using the poorly known buttonquails (Turnicidae) as a case study. This concern index is based on two parameters: scarcity and uncertainty, which ultimately are based on two components, respectively. For every species, we defined scarcity as a combination of its frequency of occurrence (proportion of positive eBird checklists) and its relative range size, while uncertainty is a combination of the eBird effort (density of eBird checklists) and the range accuracy (proportion of positive eBird checklists within the BirdLife distribution area). We found a high correlation (Spearman r = 0.74) between our concern index and the IUCN threat categories for all buttonquail species. Then we apply this concern index to all buttonquail subspecies obtaining a ranked list for these non-assessed taxa, with some island endemic subspecies ranking very high together with the most endangered buttonquail species. Our approach is a very simple method to rank species within a given bird group and prioritize monitoring and conservation efforts. Moreover, it is also suitable for other taxonomic levels as subspecies or even for ecological units as populations, which normally lack a formal conservation status assessment.","PeriodicalId":55463,"journal":{"name":"Ardea","volume":"111 1","pages":"1 - 2"},"PeriodicalIF":0.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48319657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The White-tailed Eagle Haliaeetus albicilla may aggregate in areas with high fish supply during their autumn movements. Here, we report on data collected between 2008 and 2019 concerning numbers of White-tailed Eagles visiting fishponds located in NE Lithuania, to the east of the Baltic Sea during the autumn months. For comparison, between 2016 and 2018 we also surveyed White-tailed Eagles at another, similarly managed fishpond, located 110 km away in SE Lithuania. The number of White-tailed Eagles at the fishponds in NE Lithuania in October through December increased nearly three-fold between 2008 and 2019. The long-term increase occurred especially in November–December and much less in October, and this, together with sudden increases in numbers in certain years, suggests possible changes in their movement patterns. We found similar numbers of assembling eagles in the two fishponds in October, but in November there were significantly more eagles at the fishponds in NE Lithuania. The size of groups in autumn and the seasonal dynamics therein may differ at different stopover sites that are similar in size, harvesting practice and located in the same region. We suggest this could be due to differences in the surrounding environment.
{"title":"Contrasting Trends and Dynamics in the Autumn Aggregation of White-Tailed Eagles at Two Fishponds in Lithuania","authors":"Rimgaudas Treinys, Ervin Komar, Daiva Vaitkuvienė","doi":"10.5253/arde.2022.a34","DOIUrl":"https://doi.org/10.5253/arde.2022.a34","url":null,"abstract":"The White-tailed Eagle Haliaeetus albicilla may aggregate in areas with high fish supply during their autumn movements. Here, we report on data collected between 2008 and 2019 concerning numbers of White-tailed Eagles visiting fishponds located in NE Lithuania, to the east of the Baltic Sea during the autumn months. For comparison, between 2016 and 2018 we also surveyed White-tailed Eagles at another, similarly managed fishpond, located 110 km away in SE Lithuania. The number of White-tailed Eagles at the fishponds in NE Lithuania in October through December increased nearly three-fold between 2008 and 2019. The long-term increase occurred especially in November–December and much less in October, and this, together with sudden increases in numbers in certain years, suggests possible changes in their movement patterns. We found similar numbers of assembling eagles in the two fishponds in October, but in November there were significantly more eagles at the fishponds in NE Lithuania. The size of groups in autumn and the seasonal dynamics therein may differ at different stopover sites that are similar in size, harvesting practice and located in the same region. We suggest this could be due to differences in the surrounding environment.","PeriodicalId":55463,"journal":{"name":"Ardea","volume":"111 1","pages":"1 - 9"},"PeriodicalIF":0.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43622525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Emma Penning, Y. Verkuil, L. Klunder, Jeroen Reneerkens
Knowing what birds eat is fundamental to understand the ecology and distribution of individuals and populations. Often, diet is assessed based on field observations and excrement analyses, which has previously been the case for Sanderling Calidris alba. This may have biased their known diets towards large prey with indigestible body parts that can still be recognized in faeces or regurgitations. A literature review of Sanderling diet worldwide showed that Sanderlings exploit a large diversity of prey. We carried out DNA metabarcoding on Sanderling faeces to get a complete view of their diet in the Wadden Sea during staging and moult from late July to early October. Given the diversity of available prey in the Wadden Sea, it was remarkable that 94% of the samples contained Brown Shrimp Crangon crangon which, next to the Shore Crab Carcinus maenas, were also the most abundant species in the samples. This study shows that whereas Sanderling can feed on a large variety of invertebrates, in the Wadden Sea during southward staging they primarily rely on Brown Shrimp
{"title":"Sanderlings Feed on a Diverse Spectrum of Prey Worldwide but Primarily Rely on Brown Shrimp in the Wadden Sea","authors":"Emma Penning, Y. Verkuil, L. Klunder, Jeroen Reneerkens","doi":"10.5253/arde.2022.a11","DOIUrl":"https://doi.org/10.5253/arde.2022.a11","url":null,"abstract":"Knowing what birds eat is fundamental to understand the ecology and distribution of individuals and populations. Often, diet is assessed based on field observations and excrement analyses, which has previously been the case for Sanderling Calidris alba. This may have biased their known diets towards large prey with indigestible body parts that can still be recognized in faeces or regurgitations. A literature review of Sanderling diet worldwide showed that Sanderlings exploit a large diversity of prey. We carried out DNA metabarcoding on Sanderling faeces to get a complete view of their diet in the Wadden Sea during staging and moult from late July to early October. Given the diversity of available prey in the Wadden Sea, it was remarkable that 94% of the samples contained Brown Shrimp Crangon crangon which, next to the Shore Crab Carcinus maenas, were also the most abundant species in the samples. This study shows that whereas Sanderling can feed on a large variety of invertebrates, in the Wadden Sea during southward staging they primarily rely on Brown Shrimp","PeriodicalId":55463,"journal":{"name":"Ardea","volume":"110 1","pages":"187 - 199"},"PeriodicalIF":0.4,"publicationDate":"2022-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44209855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-19DOI: 10.5253/arde.v110.2022.a21
T. Piersma
{"title":"Ornithology from the FlatlandsSocially Migrating Cuckoos? on Genes Being Just One of Many Resources Shaping the Individual Development of Migration","authors":"T. Piersma","doi":"10.5253/arde.v110.2022.a21","DOIUrl":"https://doi.org/10.5253/arde.v110.2022.a21","url":null,"abstract":"","PeriodicalId":55463,"journal":{"name":"Ardea","volume":"161 4","pages":"107 - 110"},"PeriodicalIF":0.4,"publicationDate":"2022-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41275373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. G. Núñez Montellano, Alejandro Emiliano Alauie, J. I. Areta
The White-throated Cacholote Pseudoseisura gutturalis is a little studied, socially monogamous furnariid, endemic to arid Argentina. Here we provide novel information to characterize the breeding biology of the northern subspecies ochroleuca in the Monte Desert, Argentina, and discuss the similarities and differences with other Pseudoseisura species. Nests were bulky enclosed structures constructed with thorny sticks and twigs of native plant species (n = 15) and 47% of them had objects used as external decorations. Nests had an entrance tube oriented preferentially towards the northeast, probably to avoid the prevailing south-southeast winds at the study site, and were placed at a mean height of 2.1 m above the ground (n = 13). Most of the active nests (93%) were built in columnar cacti Trichocereus atacamensis that were healthier and with fewer branches than nearby available conspecifics. Mean clutch size was 3.2 white eggs (n = 9) and the incubation period was c. 18–20 days. Brood size ranged from one to three hatchlings (n = 12) and nestlings remained in the nest for 24–26 days until fledgling. Nests with complete clutches were found between 29 October and 1 February and nestlings were found between 1 November and 5 February. Nestlings were attended by both parents and were fed with arthropods (n = 63) and vertebrates (n = 7). Nest visitation rate per nestling was similar among nests with three and two nestlings and lower than for a nest with one nestling. The breeding success was high during the incubation (73%) and nestling rearing (82%) stages. Our data show that Pseudoseisura species are similar in some aspects of their breeding biology (e.g. nest dimensions, nest decorations, mating system, clutch size), whereas other aspects, such as nest-site selection, nestling period and nest attendance rate, are more variable among species.
{"title":"Breeding Biology of the White-Throated Cacholote Pseudoseisura gutturalis ochroleuca, an Endemic Bird of the Monte Desert","authors":"M. G. Núñez Montellano, Alejandro Emiliano Alauie, J. I. Areta","doi":"10.5253/arde.2022.a12","DOIUrl":"https://doi.org/10.5253/arde.2022.a12","url":null,"abstract":"The White-throated Cacholote Pseudoseisura gutturalis is a little studied, socially monogamous furnariid, endemic to arid Argentina. Here we provide novel information to characterize the breeding biology of the northern subspecies ochroleuca in the Monte Desert, Argentina, and discuss the similarities and differences with other Pseudoseisura species. Nests were bulky enclosed structures constructed with thorny sticks and twigs of native plant species (n = 15) and 47% of them had objects used as external decorations. Nests had an entrance tube oriented preferentially towards the northeast, probably to avoid the prevailing south-southeast winds at the study site, and were placed at a mean height of 2.1 m above the ground (n = 13). Most of the active nests (93%) were built in columnar cacti Trichocereus atacamensis that were healthier and with fewer branches than nearby available conspecifics. Mean clutch size was 3.2 white eggs (n = 9) and the incubation period was c. 18–20 days. Brood size ranged from one to three hatchlings (n = 12) and nestlings remained in the nest for 24–26 days until fledgling. Nests with complete clutches were found between 29 October and 1 February and nestlings were found between 1 November and 5 February. Nestlings were attended by both parents and were fed with arthropods (n = 63) and vertebrates (n = 7). Nest visitation rate per nestling was similar among nests with three and two nestlings and lower than for a nest with one nestling. The breeding success was high during the incubation (73%) and nestling rearing (82%) stages. Our data show that Pseudoseisura species are similar in some aspects of their breeding biology (e.g. nest dimensions, nest decorations, mating system, clutch size), whereas other aspects, such as nest-site selection, nestling period and nest attendance rate, are more variable among species.","PeriodicalId":55463,"journal":{"name":"Ardea","volume":"110 1","pages":"125 - 136"},"PeriodicalIF":0.4,"publicationDate":"2022-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41366092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Modern agricultural landscapes suffer heavily from biodiversity loss. To counter this loss, it is important to understand the key factors that affect biodiversity in these landscapes. We studied the relationships between breeding birds and the habitat characteristics of the small-scale hedgerow landscapes of East-Fryslân, The Netherlands, a typical agricultural landscape that is under pressure from upscaling and habitat degradation. We questioned whether our findings collaborate the results of hedgerow studies from other countries. We also analysed whether agri-environmental schemes were effective for breeding birds. In this study, breeding birds and fifteen habitat factors were surveyed along 170 transects in two different regions in East-Fryslân in 2018. 37 bird species were identified, of which 19 were woodland species, 18 shrub species and 7 hedgerow specialists. We found five habitat characteristics to be key factors for breeding bird numbers. Four of these factors were intrinsic factors of the hedges (i.e. shrub cover, cover of brambles and nettles, crown width, hedge width at the base) and one spatial factor (i.e. number of hedge corners within a 150-m radius, corresponding to hedge intersections). Four key factors were the same for the two regions, but effect sizes differed between factors and species groups. As proxies for habitat volume (amount of habitat), the intrinsic key factors for hedgerow breeding birds in East-Fryslân correspond to those found in Britain and Eastern Europe, despite considerable differences in botanical composition, structure and management of the hedges. In contrast to studies on British hedges, we found mainly quantitative key factors and only one qualitative factor (cover of brambles and nettles). We found one spatial key factor (hedge intersections) and no correlation of bird numbers with density of hedges in the vicinity. We discuss the ecology of the key factors with respect to food provisioning and breeding. We also conclude that agri-environmental schemes favour key habitat factors and through this shrub birds. Implications of our findings are that traditional management favours breeding birds, but also that management should partly be extensified.
{"title":"Key Habitat Factors of Breeding Birds in Agricultural Hedgerow Landscapes in East-Fryslân, the Netherlands, in European Perspective – Ecological Evaluation and Relation to Agri-Environmental Schemes","authors":"E. Oosterveld, E. Klop, Els van der Zee","doi":"10.5253/arde.2022.a9","DOIUrl":"https://doi.org/10.5253/arde.2022.a9","url":null,"abstract":"Modern agricultural landscapes suffer heavily from biodiversity loss. To counter this loss, it is important to understand the key factors that affect biodiversity in these landscapes. We studied the relationships between breeding birds and the habitat characteristics of the small-scale hedgerow landscapes of East-Fryslân, The Netherlands, a typical agricultural landscape that is under pressure from upscaling and habitat degradation. We questioned whether our findings collaborate the results of hedgerow studies from other countries. We also analysed whether agri-environmental schemes were effective for breeding birds. In this study, breeding birds and fifteen habitat factors were surveyed along 170 transects in two different regions in East-Fryslân in 2018. 37 bird species were identified, of which 19 were woodland species, 18 shrub species and 7 hedgerow specialists. We found five habitat characteristics to be key factors for breeding bird numbers. Four of these factors were intrinsic factors of the hedges (i.e. shrub cover, cover of brambles and nettles, crown width, hedge width at the base) and one spatial factor (i.e. number of hedge corners within a 150-m radius, corresponding to hedge intersections). Four key factors were the same for the two regions, but effect sizes differed between factors and species groups. As proxies for habitat volume (amount of habitat), the intrinsic key factors for hedgerow breeding birds in East-Fryslân correspond to those found in Britain and Eastern Europe, despite considerable differences in botanical composition, structure and management of the hedges. In contrast to studies on British hedges, we found mainly quantitative key factors and only one qualitative factor (cover of brambles and nettles). We found one spatial key factor (hedge intersections) and no correlation of bird numbers with density of hedges in the vicinity. We discuss the ecology of the key factors with respect to food provisioning and breeding. We also conclude that agri-environmental schemes favour key habitat factors and through this shrub birds. Implications of our findings are that traditional management favours breeding birds, but also that management should partly be extensified.","PeriodicalId":55463,"journal":{"name":"Ardea","volume":"110 1","pages":"111 - 124"},"PeriodicalIF":0.4,"publicationDate":"2022-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43968739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Some bird species change their plumage colour on a seasonal basis, mostly between cryptic non-breeding plumage and conspicuous breeding plumage. Adult Common Terns Sterna hirundo moult their body feathers twice each year, resulting in two types of plumages, those typical to breeding and non-breeding seasons, which exhibit minor differences in the colours of some feathers, as well as the bare parts. Here, we report evidence of an abnormal plumage in adult Common Terns (sometimes referred to as ‘portlandica’), with two individuals exhibiting non-breeding like plumage during the breeding season. These terns were documented in a breeding colony in Northern Israel. This report could lead to future research into the causes and consequences of plumage maturation avoidance in adult birds.
{"title":"Abnormal Plumage in Adult Common Terns Sterna hirundo during the Breeding Season","authors":"Yosef Kiat, Asaf Mayrose, Inbal Schekler","doi":"10.5253/arde.2022.a7","DOIUrl":"https://doi.org/10.5253/arde.2022.a7","url":null,"abstract":"Some bird species change their plumage colour on a seasonal basis, mostly between cryptic non-breeding plumage and conspicuous breeding plumage. Adult Common Terns Sterna hirundo moult their body feathers twice each year, resulting in two types of plumages, those typical to breeding and non-breeding seasons, which exhibit minor differences in the colours of some feathers, as well as the bare parts. Here, we report evidence of an abnormal plumage in adult Common Terns (sometimes referred to as ‘portlandica’), with two individuals exhibiting non-breeding like plumage during the breeding season. These terns were documented in a breeding colony in Northern Israel. This report could lead to future research into the causes and consequences of plumage maturation avoidance in adult birds.","PeriodicalId":55463,"journal":{"name":"Ardea","volume":"110 1","pages":"1 - 6"},"PeriodicalIF":0.4,"publicationDate":"2022-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41921077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Studies examining breeding biology provide information about reproductive parameters, which are useful in formulating life-history theories. Although these studies have notably increased in the Neotropics in recent years, some gaps remain; thus, more research is needed to better understand life-history strategies of New World birds. Furthermore, research into the breeding biology of migratory birds is crucial to advance our understanding of trade-offs between reproduction and migration in Neotropical austral migrant birds. Our aims were to describe in detail the breeding biology of the Chilean Elaenia Elaenia chilensis, a long-distance Neotropical austral migrant, and to discuss current life-history theories for New World passerines. We monitored 113 nests during four consecutive breeding seasons (2014/2015–2017/2018) in the Andean-Patagonian Forest. The breeding season lasted 77 days and the nesting period, from egg laying to fledging, had a mean duration of 29.9 days. Mean clutch size was 2.4 eggs (range: 1–3) and decreased throughout the breeding season. The incubation and nestling stages lasted c. 14 days each. Fledgling number also decreased as the season progressed. The mean ± SE daily nest survival rate was 0.960 ± 0.005, corresponding to an overall nest success of 29.5%. Predation was the main cause of nest loss (61.1%). Reproductive parameters of the Chilean Elaenia coincide with characteristics of high-survival species that invest little in reproduction. Despite being a long-distance migrant, its life-history strategy does not seem to be much faster than that of its tropical resident congeners. This might not support the result reported in the Northern Hemisphere that migratory birds have a faster pace of life than resident birds.
{"title":"Breeding Biology of the Chilean Elaenia Elaenia chilensis, a Long-Distance Migratory Passerine in South America","authors":"Cristian A. Gorosito, D. T. Tuero, V. Cueto","doi":"10.5253/arde.2022.a8","DOIUrl":"https://doi.org/10.5253/arde.2022.a8","url":null,"abstract":"Studies examining breeding biology provide information about reproductive parameters, which are useful in formulating life-history theories. Although these studies have notably increased in the Neotropics in recent years, some gaps remain; thus, more research is needed to better understand life-history strategies of New World birds. Furthermore, research into the breeding biology of migratory birds is crucial to advance our understanding of trade-offs between reproduction and migration in Neotropical austral migrant birds. Our aims were to describe in detail the breeding biology of the Chilean Elaenia Elaenia chilensis, a long-distance Neotropical austral migrant, and to discuss current life-history theories for New World passerines. We monitored 113 nests during four consecutive breeding seasons (2014/2015–2017/2018) in the Andean-Patagonian Forest. The breeding season lasted 77 days and the nesting period, from egg laying to fledging, had a mean duration of 29.9 days. Mean clutch size was 2.4 eggs (range: 1–3) and decreased throughout the breeding season. The incubation and nestling stages lasted c. 14 days each. Fledgling number also decreased as the season progressed. The mean ± SE daily nest survival rate was 0.960 ± 0.005, corresponding to an overall nest success of 29.5%. Predation was the main cause of nest loss (61.1%). Reproductive parameters of the Chilean Elaenia coincide with characteristics of high-survival species that invest little in reproduction. Despite being a long-distance migrant, its life-history strategy does not seem to be much faster than that of its tropical resident congeners. This might not support the result reported in the Northern Hemisphere that migratory birds have a faster pace of life than resident birds.","PeriodicalId":55463,"journal":{"name":"Ardea","volume":"110 1","pages":"1 - 12"},"PeriodicalIF":0.4,"publicationDate":"2022-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41885216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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