Pub Date : 2021-07-03DOI: 10.1080/00063657.2022.2103515
Alan McCarthy, P. Smiddy, T. Nagle, A. Mee, S. Irwin, Anthony Caravaggi, J. O’Halloran
ABSTRACT Capsule Habitat composition plays a key role in determining the winter diet of the Hen Harrier Circus cyaneus, which varies across the winter season and between years. Aims To determine the winter diet of the Hen Harrier and examine temporal and spatial variations in diet composition. Methods A total of 1117 Hen Harrier pellets were collected from 11 winter roosts between 2017 and 2021 in Ireland. Results Hen Harrier winter diet was dominated by avian prey (95.9% of pellets), with mammalian prey found in 12.0% of pellets. The occurrence of small birds and small mammals in the diet was positively associated with the proportion of arable, wild bird cover, and low-intensity agriculture around the roost sites. The frequency of medium-sized birds (primarily Redwing Turdus iliacus and Common Snipe Gallinago gallinago) in the diet was positively associated with the proportion of bog and young conifer forests surrounding roost sites. Diet varied across regions, with pellets from roosts in lowland coastal areas having a greater prevalence of small birds and small mammals, and pellets from roosts in upland areas having a greater prevalence of medium-sized birds. The proportion of medium-sized birds in the diet changed across months, with that of small birds and small mammals remaining stable. There was also variation between winters in the proportion of small- and medium-sized birds in the diet. Conclusions Habitat, along with region and time, are important drivers of variation in Hen Harrier diet. Our findings highlight the opportunity for the enhancement of Hen Harrier habitat through land management, and can be used to inform effective conservation strategies for wintering Hen Harriers at a landscape scale.
{"title":"Landscape and temporal influences on the winter diet of a threatened diurnal raptor, the Hen Harrier Circus cyaneus","authors":"Alan McCarthy, P. Smiddy, T. Nagle, A. Mee, S. Irwin, Anthony Caravaggi, J. O’Halloran","doi":"10.1080/00063657.2022.2103515","DOIUrl":"https://doi.org/10.1080/00063657.2022.2103515","url":null,"abstract":"ABSTRACT Capsule Habitat composition plays a key role in determining the winter diet of the Hen Harrier Circus cyaneus, which varies across the winter season and between years. Aims To determine the winter diet of the Hen Harrier and examine temporal and spatial variations in diet composition. Methods A total of 1117 Hen Harrier pellets were collected from 11 winter roosts between 2017 and 2021 in Ireland. Results Hen Harrier winter diet was dominated by avian prey (95.9% of pellets), with mammalian prey found in 12.0% of pellets. The occurrence of small birds and small mammals in the diet was positively associated with the proportion of arable, wild bird cover, and low-intensity agriculture around the roost sites. The frequency of medium-sized birds (primarily Redwing Turdus iliacus and Common Snipe Gallinago gallinago) in the diet was positively associated with the proportion of bog and young conifer forests surrounding roost sites. Diet varied across regions, with pellets from roosts in lowland coastal areas having a greater prevalence of small birds and small mammals, and pellets from roosts in upland areas having a greater prevalence of medium-sized birds. The proportion of medium-sized birds in the diet changed across months, with that of small birds and small mammals remaining stable. There was also variation between winters in the proportion of small- and medium-sized birds in the diet. Conclusions Habitat, along with region and time, are important drivers of variation in Hen Harrier diet. Our findings highlight the opportunity for the enhancement of Hen Harrier habitat through land management, and can be used to inform effective conservation strategies for wintering Hen Harriers at a landscape scale.","PeriodicalId":55353,"journal":{"name":"Bird Study","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47105963","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 : 2021-07-03DOI: 10.1080/00063657.2022.2049204
U. Bergmanis, A. Auniņš
ABSTRACT Capsule Small rodents and amphibians are both important prey items for the Lesser Spotted Eagle Clanga pomarina, and their proportions in the diet depend on their local availability, as well as the degree of involvement of the female in food provisioning to the nestlings, which increases towards the end of the breeding season. Aims To describe the diet composition and aspects of the food supply of the Lesser Spotted Eagle during the nesting period. Methods Cameras were installed at five nests of three pairs of the Lesser Spotted Eagle in eastern Latvia, to collect data on food items brought to the nests. Results Of 3109 identified prey items, small rodents (43.36%) and amphibians (44.81%) were the most important prey groups. The proportion of common (small rodents and amphibians) and uncommon (moles, birds and others) food items differed between nests and years. Among the common food items, the deficiency of small rodents in some years was compensated for by an increase in frogs and vice versa. Male eagles brought 66% of all food items to the nest. Females brought more amphibians and fewer rodents than did males. After hatching, the mean number of food items delivered to the nest was 6.9 per day. The main activity period of food delivery was between the 3rd to 7th hour after sunrise. Conclusion The alternative prey hypothesis explains the diet of the Lesser Spotted Eagle in our study area. Rodents and amphibians are food items of equal importance that can replace each other, depending on their availability. The increasing share of amphibians towards the end of the breeding season was mainly a result of an increasing proportion of prey items brought into the nest by females.
{"title":"Diet composition and food supply of the Lesser Spotted Eagle Clanga pomarina in the core area of its breeding range","authors":"U. Bergmanis, A. Auniņš","doi":"10.1080/00063657.2022.2049204","DOIUrl":"https://doi.org/10.1080/00063657.2022.2049204","url":null,"abstract":"ABSTRACT Capsule Small rodents and amphibians are both important prey items for the Lesser Spotted Eagle Clanga pomarina, and their proportions in the diet depend on their local availability, as well as the degree of involvement of the female in food provisioning to the nestlings, which increases towards the end of the breeding season. Aims To describe the diet composition and aspects of the food supply of the Lesser Spotted Eagle during the nesting period. Methods Cameras were installed at five nests of three pairs of the Lesser Spotted Eagle in eastern Latvia, to collect data on food items brought to the nests. Results Of 3109 identified prey items, small rodents (43.36%) and amphibians (44.81%) were the most important prey groups. The proportion of common (small rodents and amphibians) and uncommon (moles, birds and others) food items differed between nests and years. Among the common food items, the deficiency of small rodents in some years was compensated for by an increase in frogs and vice versa. Male eagles brought 66% of all food items to the nest. Females brought more amphibians and fewer rodents than did males. After hatching, the mean number of food items delivered to the nest was 6.9 per day. The main activity period of food delivery was between the 3rd to 7th hour after sunrise. Conclusion The alternative prey hypothesis explains the diet of the Lesser Spotted Eagle in our study area. Rodents and amphibians are food items of equal importance that can replace each other, depending on their availability. The increasing share of amphibians towards the end of the breeding season was mainly a result of an increasing proportion of prey items brought into the nest by females.","PeriodicalId":55353,"journal":{"name":"Bird Study","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42477889","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 : 2021-07-03DOI: 10.1080/00063657.2022.2092593
R. Ziani, A. Lazli, F. Marniche, B. E. Ziani, B. Dik
ABSTRACT Capsule The distribution and prevalence of chewing lice found on Common Moorhens Gallinula chloropus varied between seasons and peaked during the winter. There was also significant variation in how lice were distributed around the body regions of the hosts. Aims To identify the species of lice found on the Common Moorhen, evaluate the seasonal variation in their intensity of infestation and determine spatial distribution on the hosts. Methods Eighty-six Common Moorhens were captured, examined for lice, and released from December 2018 to February 2020 at Lake Tonga, Algeria. Lice were extracted, preserved in 70% ethanol, cleared, and mounted in Canada balsam for identification. The population mean intensity and prevalence of lice species were calculated for each season. Data were inspected using descriptive statistical tools, such as principal component analysis, to explore spatial dispersion on the body regions of the hosts. Results Five louse species were identified: Pseudomenopon pilosum, Rallicola minutus, Laemobothrion chloropodis, Fulicoffula sp, and Incidifrons gallinulae, with percentages of prevalence of 79.07%, 70.93%, 56.98%, 40.70%, and 23.26%, respectively. Their prevalence varied significantly across months, with a peak in the winter. Louse species were non-randomly distributed across the body regions of the hosts. Conclusion This study documents the distribution and diversity of chewing lice on the Common Moorhen for the first time in Algeria and establishes a baseline dataset for further monitoring studies.
{"title":"The distribution and diversity of chewing lice (Phthiraptera) on the Common Moorhen Gallinula chloropus in Algeria","authors":"R. Ziani, A. Lazli, F. Marniche, B. E. Ziani, B. Dik","doi":"10.1080/00063657.2022.2092593","DOIUrl":"https://doi.org/10.1080/00063657.2022.2092593","url":null,"abstract":"ABSTRACT Capsule The distribution and prevalence of chewing lice found on Common Moorhens Gallinula chloropus varied between seasons and peaked during the winter. There was also significant variation in how lice were distributed around the body regions of the hosts. Aims To identify the species of lice found on the Common Moorhen, evaluate the seasonal variation in their intensity of infestation and determine spatial distribution on the hosts. Methods Eighty-six Common Moorhens were captured, examined for lice, and released from December 2018 to February 2020 at Lake Tonga, Algeria. Lice were extracted, preserved in 70% ethanol, cleared, and mounted in Canada balsam for identification. The population mean intensity and prevalence of lice species were calculated for each season. Data were inspected using descriptive statistical tools, such as principal component analysis, to explore spatial dispersion on the body regions of the hosts. Results Five louse species were identified: Pseudomenopon pilosum, Rallicola minutus, Laemobothrion chloropodis, Fulicoffula sp, and Incidifrons gallinulae, with percentages of prevalence of 79.07%, 70.93%, 56.98%, 40.70%, and 23.26%, respectively. Their prevalence varied significantly across months, with a peak in the winter. Louse species were non-randomly distributed across the body regions of the hosts. Conclusion This study documents the distribution and diversity of chewing lice on the Common Moorhen for the first time in Algeria and establishes a baseline dataset for further monitoring studies.","PeriodicalId":55353,"journal":{"name":"Bird Study","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49083625","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 : 2021-07-03DOI: 10.1080/00063657.2022.2026876
Tina Petras, A. Vrezec
ABSTRACT Capsule Long-term and non-standardized migratory bird ringing data can be used in models controlling variation in bird ringing methodology for reliable population trend estimations. Aims Bird ringing data usually cover long periods and might reflect long-term population changes. However, they are mainly derived during non-standardized multi-species catching at numerous sites during the autumn migration period. We searched for the best modelling approach to determine reliable species population dynamics and trend estimation models based on annual multi-species bird ringing data. Methods We used ringing data from the Slovenian Bird Ringing Scheme and selected data in three steps according to temporal, quantitative, and qualitative data selection. Annual indices were constructed based on two types of denominators, ringing days, and ringing totals, vs. a robust model without a denominator. We ran 20 candidate-generalized additive models describing migrating population dynamics for 15 bird species by combining different data selection approaches and denominators. Results We found that the models were species-specific, although the universal model could also be applied to most species. We propose a general model construction approach for population trend assessments from non-standardized bird ringing data. The estimates obtained by this approach were comparable to the overall European population trends derived from breeding survey data. Conclusions Bird ringing data from the autumn migration period are a valuable resource for assessing continental scale population trends taking into account the whole population (non-breeders and juveniles included) and even some rare and endangered species, but should be conducted according to standard protocols to ensure reliable statistical inference of population trends.
{"title":"Modelling population dynamics and trends in migratory birds from non-standardized multi-species ringing data: the potential of multi-model selection","authors":"Tina Petras, A. Vrezec","doi":"10.1080/00063657.2022.2026876","DOIUrl":"https://doi.org/10.1080/00063657.2022.2026876","url":null,"abstract":"ABSTRACT Capsule Long-term and non-standardized migratory bird ringing data can be used in models controlling variation in bird ringing methodology for reliable population trend estimations. Aims Bird ringing data usually cover long periods and might reflect long-term population changes. However, they are mainly derived during non-standardized multi-species catching at numerous sites during the autumn migration period. We searched for the best modelling approach to determine reliable species population dynamics and trend estimation models based on annual multi-species bird ringing data. Methods We used ringing data from the Slovenian Bird Ringing Scheme and selected data in three steps according to temporal, quantitative, and qualitative data selection. Annual indices were constructed based on two types of denominators, ringing days, and ringing totals, vs. a robust model without a denominator. We ran 20 candidate-generalized additive models describing migrating population dynamics for 15 bird species by combining different data selection approaches and denominators. Results We found that the models were species-specific, although the universal model could also be applied to most species. We propose a general model construction approach for population trend assessments from non-standardized bird ringing data. The estimates obtained by this approach were comparable to the overall European population trends derived from breeding survey data. Conclusions Bird ringing data from the autumn migration period are a valuable resource for assessing continental scale population trends taking into account the whole population (non-breeders and juveniles included) and even some rare and endangered species, but should be conducted according to standard protocols to ensure reliable statistical inference of population trends.","PeriodicalId":55353,"journal":{"name":"Bird Study","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42419911","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 : 2021-07-03DOI: 10.1080/00063657.2022.2032590
Michał Budka, Patryk Kokociński
ABSTRACT Capsule The vocal activity of Common Cranes Grus grus varies with time of day, season, population abundance, and nesting habitat area, and consequently affects the accuracy and precision of single survey estimates of breeding population size. Aims To examine (1) how the vocal activity of Common Cranes varies during the day and seasonally, (2) how these changes affect the probability of observer detection of a pair during a single survey, and (3) which environmental variables influence vocal activity. Methods Autonomous sound recorders recorded soundscapes (24 hours per day) in 24 occupied territories of Common Cranes, three times during the breeding season. Recordings were analysed by manual spectrogram scanning. The probability of detection was calculated for four survey durations: 10 and 30 min, one and two hours. Environmental characteristics were measured from satellite images. Results Common Crane vocal activity during a single survey significantly varied during the day, decreased with the progress of the breeding season, negatively correlated with the area of nesting habitat, and positively correlated with the number of neighbouring pairs within 2 km. 24-hour surveys recorded at least one vocalization in 96% of occupied territories in March, 67% in April, and 46% in May. The highest probability of detection during a single, one-hour survey ranged from 0.46 in March, 0.25 in April to 0.17 in May. Reducing survey duration from 1 h to 10 min caused a decrease of detection to 0.29 in March and 0.13 in April and May. Conclusions We recommend surveying Common Cranes at the beginning of the breeding season, from one hour before sunrise to four hours after sunrise and from sunset to one hour after sunset, to ensure the highest (0.33–0.46) probability of detection during a single, one-hour survey. Alternatively, autonomous sound recorders may ensure detection of almost 100% of breeding pairs during a single, 24-hour survey at the beginning of the breeding season.
{"title":"Daily and seasonal changes of vocal activity of the Common Crane Grus grus: implications for conservation and monitoring efforts","authors":"Michał Budka, Patryk Kokociński","doi":"10.1080/00063657.2022.2032590","DOIUrl":"https://doi.org/10.1080/00063657.2022.2032590","url":null,"abstract":"ABSTRACT Capsule The vocal activity of Common Cranes Grus grus varies with time of day, season, population abundance, and nesting habitat area, and consequently affects the accuracy and precision of single survey estimates of breeding population size. Aims To examine (1) how the vocal activity of Common Cranes varies during the day and seasonally, (2) how these changes affect the probability of observer detection of a pair during a single survey, and (3) which environmental variables influence vocal activity. Methods Autonomous sound recorders recorded soundscapes (24 hours per day) in 24 occupied territories of Common Cranes, three times during the breeding season. Recordings were analysed by manual spectrogram scanning. The probability of detection was calculated for four survey durations: 10 and 30 min, one and two hours. Environmental characteristics were measured from satellite images. Results Common Crane vocal activity during a single survey significantly varied during the day, decreased with the progress of the breeding season, negatively correlated with the area of nesting habitat, and positively correlated with the number of neighbouring pairs within 2 km. 24-hour surveys recorded at least one vocalization in 96% of occupied territories in March, 67% in April, and 46% in May. The highest probability of detection during a single, one-hour survey ranged from 0.46 in March, 0.25 in April to 0.17 in May. Reducing survey duration from 1 h to 10 min caused a decrease of detection to 0.29 in March and 0.13 in April and May. Conclusions We recommend surveying Common Cranes at the beginning of the breeding season, from one hour before sunrise to four hours after sunrise and from sunset to one hour after sunset, to ensure the highest (0.33–0.46) probability of detection during a single, one-hour survey. Alternatively, autonomous sound recorders may ensure detection of almost 100% of breeding pairs during a single, 24-hour survey at the beginning of the breeding season.","PeriodicalId":55353,"journal":{"name":"Bird Study","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48133043","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 : 2021-07-03DOI: 10.1080/00063657.2022.2095350
Jan van der Winden, Niels Hogeweg, Edwin W. Baaij, P. V. van Horssen, J. Shamoun‐Baranes, René Vos, T. Piersma
ABSTRACT Capsule Migration studies of tagged Eurasian Bitterns Botaurus stellaris provide information on the behaviour of this secretive species in relation to weather conditions. Aims To study if cold spells trigger southward migration in resident Eurasian Bitterns. To describe migratory behaviour including flight routes, altitudes, flight direction in relation to wind speed and direction, and general characteristics of stopping sites. Methods Six adult Eurasian Bitterns from Dutch breeding areas were followed for two to five years using ARGOS-PTT/GPS transmitters or GPS trackers. Results Four individuals remained at the breeding sites in winter and did not migrate in response to cold spells. Two individuals covered distances of 300 and 1600 km between stopping sites. They migrated predominantly at night, but over the Sahara they extended flights into daylight hours. Depending on wind assistance, flight speeds (groundspeed) varied between 3.6 and 26 ms−1. Flight altitude varied from just above sea level when facing headwinds, to almost 2000 m above sea level under tail wind conditions. Repeatedly tracked individuals showed substantial variation in routes and stopping sites between successive migrations. These flight patterns appeared influenced by the speed and direction of the winds encountered en route. Conclusions Eurasian Bitterns were either migratory or resident and the latter individuals did not perform facultative movements at the onset of cold spells. The flight speed, flight altitudes, and routes of migrating birds were influenced by wind conditions. This likely explains the variable use of stopping sites between years.
{"title":"The influence of weather on the migration behaviour of Eurasian Bitterns Botaurus stellaris","authors":"Jan van der Winden, Niels Hogeweg, Edwin W. Baaij, P. V. van Horssen, J. Shamoun‐Baranes, René Vos, T. Piersma","doi":"10.1080/00063657.2022.2095350","DOIUrl":"https://doi.org/10.1080/00063657.2022.2095350","url":null,"abstract":"ABSTRACT Capsule Migration studies of tagged Eurasian Bitterns Botaurus stellaris provide information on the behaviour of this secretive species in relation to weather conditions. Aims To study if cold spells trigger southward migration in resident Eurasian Bitterns. To describe migratory behaviour including flight routes, altitudes, flight direction in relation to wind speed and direction, and general characteristics of stopping sites. Methods Six adult Eurasian Bitterns from Dutch breeding areas were followed for two to five years using ARGOS-PTT/GPS transmitters or GPS trackers. Results Four individuals remained at the breeding sites in winter and did not migrate in response to cold spells. Two individuals covered distances of 300 and 1600 km between stopping sites. They migrated predominantly at night, but over the Sahara they extended flights into daylight hours. Depending on wind assistance, flight speeds (groundspeed) varied between 3.6 and 26 ms−1. Flight altitude varied from just above sea level when facing headwinds, to almost 2000 m above sea level under tail wind conditions. Repeatedly tracked individuals showed substantial variation in routes and stopping sites between successive migrations. These flight patterns appeared influenced by the speed and direction of the winds encountered en route. Conclusions Eurasian Bitterns were either migratory or resident and the latter individuals did not perform facultative movements at the onset of cold spells. The flight speed, flight altitudes, and routes of migrating birds were influenced by wind conditions. This likely explains the variable use of stopping sites between years.","PeriodicalId":55353,"journal":{"name":"Bird Study","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42201649","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 : 2021-07-03DOI: 10.1080/00063657.2022.2027341
V. Ivanitskii, I. Syomina, Irina Ilina, I. Marova, Ilya Kislyakov
ABSTRACT Capsule Although many acoustic signals of Common Chaffinches Fringilla coelebs, including both songs and rain calls, are widespread across its distribution range, the boundaries between subspecies place formidable obstacles to the spread of vocal patterns. Aims To investigate the diversity of song types and song structure of rain calls in the contact zone between the Caucasian and Crimean subspecies of Chaffinches in the north-western Caucasus, as well as between the nominate and Caucasian subspecies in the northern Ciscaucasia (south of European Russia). Methods In total, the songs and rain calls of more than 300 males were recorded in 10 different locations in the Crimea, Caucasus, and Ciscaucasia. For comparison with more remote areas, we used our recording of Chaffinches from the Voronezh region and the city of Moscow. Results The song repertoires of Chaffinches in the Crimea and on the Abrau Peninsula (Black Sea basin) were very different despite being less than 100 km apart. In contrast, the repertoire of the Abrau population had much in common with the more distant (270–300 km) populations of the Caucasus and Ciscaucasia. The rain calls of Chaffinches on the Abrau had a unique two-syllable structure. On a sonogram, both of these types of sounds look very similar to the single-element calls of Caucasian and Crimean Chaffinches, but are significantly different in their frequency and temporal characteristics. Conclusion Zones of contact between Chaffinch subspecies appear to be a kind of filter that make it difficult to spread vocal patterns from the range of one subspecies to the range of another.
{"title":"Travelling across subspecies borders: songs and calls of the Common Chaffinch Fringilla coelebs in the contact zones and adjoining areas of southern Russia","authors":"V. Ivanitskii, I. Syomina, Irina Ilina, I. Marova, Ilya Kislyakov","doi":"10.1080/00063657.2022.2027341","DOIUrl":"https://doi.org/10.1080/00063657.2022.2027341","url":null,"abstract":"ABSTRACT Capsule Although many acoustic signals of Common Chaffinches Fringilla coelebs, including both songs and rain calls, are widespread across its distribution range, the boundaries between subspecies place formidable obstacles to the spread of vocal patterns. Aims To investigate the diversity of song types and song structure of rain calls in the contact zone between the Caucasian and Crimean subspecies of Chaffinches in the north-western Caucasus, as well as between the nominate and Caucasian subspecies in the northern Ciscaucasia (south of European Russia). Methods In total, the songs and rain calls of more than 300 males were recorded in 10 different locations in the Crimea, Caucasus, and Ciscaucasia. For comparison with more remote areas, we used our recording of Chaffinches from the Voronezh region and the city of Moscow. Results The song repertoires of Chaffinches in the Crimea and on the Abrau Peninsula (Black Sea basin) were very different despite being less than 100 km apart. In contrast, the repertoire of the Abrau population had much in common with the more distant (270–300 km) populations of the Caucasus and Ciscaucasia. The rain calls of Chaffinches on the Abrau had a unique two-syllable structure. On a sonogram, both of these types of sounds look very similar to the single-element calls of Caucasian and Crimean Chaffinches, but are significantly different in their frequency and temporal characteristics. Conclusion Zones of contact between Chaffinch subspecies appear to be a kind of filter that make it difficult to spread vocal patterns from the range of one subspecies to the range of another.","PeriodicalId":55353,"journal":{"name":"Bird Study","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47061384","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 : 2021-07-03DOI: 10.1080/00063657.2022.2049205
Ian D. Woodward, G. Austin, Philipp H. Boersch-Supan, C. Thaxter, N. Burton
ABSTRACT Capsule We assessed annual changes in Eurasian Curlew Numenius arquata wintering numbers at estuaries in England and Wales over 40 years against local and broadscale factors. Long-term trends likely reflect the cessation of hunting, but potentially also distributional changes associated with milder winters and changes in breeding success. Aims To investigate whether local or broadscale factors might affect site-level annual abundance changes in Curlews in England and Wales. Methods Relationships between Wetland Bird Survey (WeBS) counts from 46 estuaries from 1974/75 to 2016/17 and environmental data were assessed using Generalized Linear Mixed Models. Results The winter abundance trend of Curlews in England and Wales closely matched the decline of breeding populations since the mid-1990s. However, there are clear differences in the trends prior to this. Our analysis suggests that winter counts were influenced by the cessation of hunting and by weather, with abundance decreasing during cold winters and increasing the following winter. The influence of severe weather was less pronounced in the immediate aftermath of the hunting ban. An increase in numbers in the east of the UK also occurred during this period. No effects were detected for other environmental variables, but this may reflect the fact that only static variation between sites was tested for these variables rather than change. Conclusion The increase in wintering Curlew numbers in the UK during the 1980s and early 1990s likely reflects a positive response to the cessation of hunting, but also a wider redistribution associated with milder winters across the European wintering range. Winter temperatures influenced annual abundance changes at individual sites, although impacts on detectability are difficult to disentangle from impacts on survival using WeBS counts alone. Factors operating during the breeding season are likely to be the main drivers of the current population decline.
{"title":"Assessing drivers of winter abundance change in Eurasian Curlews Numenius arquata in England and Wales","authors":"Ian D. Woodward, G. Austin, Philipp H. Boersch-Supan, C. Thaxter, N. Burton","doi":"10.1080/00063657.2022.2049205","DOIUrl":"https://doi.org/10.1080/00063657.2022.2049205","url":null,"abstract":"ABSTRACT Capsule We assessed annual changes in Eurasian Curlew Numenius arquata wintering numbers at estuaries in England and Wales over 40 years against local and broadscale factors. Long-term trends likely reflect the cessation of hunting, but potentially also distributional changes associated with milder winters and changes in breeding success. Aims To investigate whether local or broadscale factors might affect site-level annual abundance changes in Curlews in England and Wales. Methods Relationships between Wetland Bird Survey (WeBS) counts from 46 estuaries from 1974/75 to 2016/17 and environmental data were assessed using Generalized Linear Mixed Models. Results The winter abundance trend of Curlews in England and Wales closely matched the decline of breeding populations since the mid-1990s. However, there are clear differences in the trends prior to this. Our analysis suggests that winter counts were influenced by the cessation of hunting and by weather, with abundance decreasing during cold winters and increasing the following winter. The influence of severe weather was less pronounced in the immediate aftermath of the hunting ban. An increase in numbers in the east of the UK also occurred during this period. No effects were detected for other environmental variables, but this may reflect the fact that only static variation between sites was tested for these variables rather than change. Conclusion The increase in wintering Curlew numbers in the UK during the 1980s and early 1990s likely reflects a positive response to the cessation of hunting, but also a wider redistribution associated with milder winters across the European wintering range. Winter temperatures influenced annual abundance changes at individual sites, although impacts on detectability are difficult to disentangle from impacts on survival using WeBS counts alone. Factors operating during the breeding season are likely to be the main drivers of the current population decline.","PeriodicalId":55353,"journal":{"name":"Bird Study","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49501374","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 : 2021-07-03DOI: 10.1080/00063657.2022.2053944
O. Mikulica, A. Trnka
ABSTRACT Using direct observations of Common Cuckoo Cuculus canorus behaviour at 53 nests of three Acrocephalus host species, we recorded no vocal activity by females shortly before, during, or after egg-laying, which suggests that female bubbling calls during parasitism are not used as commonly as previously thought.
{"title":"On the behaviour and vocalizations of female Common Cuckoos Cuculus canorus at the host nest","authors":"O. Mikulica, A. Trnka","doi":"10.1080/00063657.2022.2053944","DOIUrl":"https://doi.org/10.1080/00063657.2022.2053944","url":null,"abstract":"ABSTRACT Using direct observations of Common Cuckoo Cuculus canorus behaviour at 53 nests of three Acrocephalus host species, we recorded no vocal activity by females shortly before, during, or after egg-laying, which suggests that female bubbling calls during parasitism are not used as commonly as previously thought.","PeriodicalId":55353,"journal":{"name":"Bird Study","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45249268","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 : 2021-07-03DOI: 10.1080/00063657.2022.2050351
D. Stoyan, Winfried Nachtigall
ABSTRACT Capsule The density of Common Tern Sterna hirundo nests on artificial islands was increased by the provision of chick shelters, which influenced the placement of nests. Aims To understand the nest placement behaviour underlying the distribution of Common Tern nests on artificial islands with and without chick shelters. Methods We studied Common Tern nest placement patterns on an artificial island in an inland pond in Germany where ridge tiles had been deployed as chick shelters. We used point process statistics, taking the nest locations as points. The pattern of nest placement was compared with simulated patterns without chick shelters: (a) a pattern derived by replacing the nest clusters around tiles in the observed pattern with single nests and (b) patterns derived from a statistical model describing nest patterns without chick shelters from a region close to the German North Sea. Results The density of nests in close proximity to ridge tiles was higher than elsewhere on the artificial island. This suggests that the presence of tiles reduced the inter-nest distances that are acceptable to breeding Common Terns. The assumed pattern without nest clusters is shown to be similar to modelled patterns based on tern colonies without chick shelters. The presence of chick shelters appears to have resulted in a 16% increase in nest density. Conclusions Chick shelters such as ridge tiles can help to increase the numbers of breeding Common Tern pairs accommodated on artificial islands.
{"title":"The effect of artificial chick shelters on nest placement by Common Terns Sterna hirundo","authors":"D. Stoyan, Winfried Nachtigall","doi":"10.1080/00063657.2022.2050351","DOIUrl":"https://doi.org/10.1080/00063657.2022.2050351","url":null,"abstract":"ABSTRACT Capsule The density of Common Tern Sterna hirundo nests on artificial islands was increased by the provision of chick shelters, which influenced the placement of nests. Aims To understand the nest placement behaviour underlying the distribution of Common Tern nests on artificial islands with and without chick shelters. Methods We studied Common Tern nest placement patterns on an artificial island in an inland pond in Germany where ridge tiles had been deployed as chick shelters. We used point process statistics, taking the nest locations as points. The pattern of nest placement was compared with simulated patterns without chick shelters: (a) a pattern derived by replacing the nest clusters around tiles in the observed pattern with single nests and (b) patterns derived from a statistical model describing nest patterns without chick shelters from a region close to the German North Sea. Results The density of nests in close proximity to ridge tiles was higher than elsewhere on the artificial island. This suggests that the presence of tiles reduced the inter-nest distances that are acceptable to breeding Common Terns. The assumed pattern without nest clusters is shown to be similar to modelled patterns based on tern colonies without chick shelters. The presence of chick shelters appears to have resulted in a 16% increase in nest density. Conclusions Chick shelters such as ridge tiles can help to increase the numbers of breeding Common Tern pairs accommodated on artificial islands.","PeriodicalId":55353,"journal":{"name":"Bird Study","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44061045","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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