P. Ghimire, Rojina Ghimire, M. Low, B. Bist, Nabin Pandey
Abstract The Asian Woollyneck Ciconia episcopus is a stork found throughout Asia whose international conservation status is currently being considered for reclassification from vulnerable to near-threatened. However, much of what is known about this species is fragmented across observational reports and small studies making a comprehensive assessment of population trends difficult. Here, we bring together all available published information to see what is known and what research questions still need answering in order to make reliable assessments of regional population trends and identify probable drivers of decline. Despite the species likely being extinct in the extremes of its former range and evidence of dramatic declines in Southeast Asia, Asian Woollyneck appears to be stable or increasing in India, Sri Lanka and Nepal. Observations of its preferred foraging and nesting habitats in South versus Southeast Asia show some obvious differences that may explain regional variations in population trends. In South Asia the bird is common in open grasslands and agricultural areas, while in Southeast Asia it is mostly observed in forested areas. Also, reports of the Asian Woollyneck nesting on cell phone towers is increasing in South Asia. However, because of a severe lack of reporting from Southeast Asia, it is unclear if or how these regional differences in population trends and habitat use are linked. Structured surveys and studies into the Asian Woollyneck foraging, nesting and movement ecology are urgently needed to understand the extent and drivers of decline in Southeast Asia. Therefore, researchers should focus future studies on population trends across the species' range, and aim to identify the local factors influencing recent changes in population growth. Without such knowledge, reassessment of its conservation status may be premature.
{"title":"The Asian Woollyneck Ciconia episcopus: A Review of its Status, Distribution and Ecology","authors":"P. Ghimire, Rojina Ghimire, M. Low, B. Bist, Nabin Pandey","doi":"10.2326/osj.20.223","DOIUrl":"https://doi.org/10.2326/osj.20.223","url":null,"abstract":"Abstract The Asian Woollyneck Ciconia episcopus is a stork found throughout Asia whose international conservation status is currently being considered for reclassification from vulnerable to near-threatened. However, much of what is known about this species is fragmented across observational reports and small studies making a comprehensive assessment of population trends difficult. Here, we bring together all available published information to see what is known and what research questions still need answering in order to make reliable assessments of regional population trends and identify probable drivers of decline. Despite the species likely being extinct in the extremes of its former range and evidence of dramatic declines in Southeast Asia, Asian Woollyneck appears to be stable or increasing in India, Sri Lanka and Nepal. Observations of its preferred foraging and nesting habitats in South versus Southeast Asia show some obvious differences that may explain regional variations in population trends. In South Asia the bird is common in open grasslands and agricultural areas, while in Southeast Asia it is mostly observed in forested areas. Also, reports of the Asian Woollyneck nesting on cell phone towers is increasing in South Asia. However, because of a severe lack of reporting from Southeast Asia, it is unclear if or how these regional differences in population trends and habitat use are linked. Structured surveys and studies into the Asian Woollyneck foraging, nesting and movement ecology are urgently needed to understand the extent and drivers of decline in Southeast Asia. Therefore, researchers should focus future studies on population trends across the species' range, and aim to identify the local factors influencing recent changes in population growth. Without such knowledge, reassessment of its conservation status may be premature.","PeriodicalId":49009,"journal":{"name":"Ornithological Science","volume":"20 1","pages":"223 - 233"},"PeriodicalIF":0.6,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44086682","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}
Abstract We report an exceptional case of Eurasian Eagle Owls Bubo bubo feeding on Stag Beetles Lucanus cervus in Germany, with the beetles making up 56.9% of all prey individuals. A review of literature and a comparison of data reveal that both the number and the biomass of the consumed beetles are typically too low to be of any nutritional importance with respect to the Eurasian Eagle Owl's broad food spectrum. Therefore, we conclude that Eurasian Eagle Owls merely opportunistically fed on this only seasonally available food source and that juvenile owls might prey on these beetles during their hunting exercises.
{"title":"Eurasian Eagle Owls Bubo bubo Opportunistically Prey on Stag Beetles Lucanus cervus","authors":"Matthias Overmann, T. Töpfer","doi":"10.2326/osj.20.235","DOIUrl":"https://doi.org/10.2326/osj.20.235","url":null,"abstract":"Abstract We report an exceptional case of Eurasian Eagle Owls Bubo bubo feeding on Stag Beetles Lucanus cervus in Germany, with the beetles making up 56.9% of all prey individuals. A review of literature and a comparison of data reveal that both the number and the biomass of the consumed beetles are typically too low to be of any nutritional importance with respect to the Eurasian Eagle Owl's broad food spectrum. Therefore, we conclude that Eurasian Eagle Owls merely opportunistically fed on this only seasonally available food source and that juvenile owls might prey on these beetles during their hunting exercises.","PeriodicalId":49009,"journal":{"name":"Ornithological Science","volume":"20 1","pages":"235 - 240"},"PeriodicalIF":0.6,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46025647","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}
Abstract Although a number of infanticide cases have been recorded among birds, since the incidence of this behavior is, overall, low and difficult to confirm, the importance of infanticide in the cause analysis of breeding failure is likely to be underestimated. During the breeding season of March to August 2019, we observed two cases of non-kin infanticide in Oriental Magpie Robins Copsychus saularis in nest boxes. The first incident occurred during the absence of the nesting male during the brooding period and in the sole presence of the female; another male entered the nest box and continuously attacked and pecked all four eight-day-old nestlings in the nest until they died. A second incident occurred in the presence of both parents, but during the feeding interval; a male perpetrator entered the nest box and pecked and pushed the single three-day-old nestling out of the box. The parents continued to carry food to the nest and tried to feed their nestling even after the latter had been killed. The parents were observed behaving anxiously once they detected no sign of activity from their nestling. We speculated that these examples of non-kin infanticide by conspecific Oriental Magpie Robin males could be attributed to competition for food resources or mates.
{"title":"Non-Kin Infanticide by Male Oriental Magpie Robins in Nest Boxes","authors":"Yameng Jin, Changzhang Feng, W. Liang","doi":"10.2326/osj.20.241","DOIUrl":"https://doi.org/10.2326/osj.20.241","url":null,"abstract":"Abstract Although a number of infanticide cases have been recorded among birds, since the incidence of this behavior is, overall, low and difficult to confirm, the importance of infanticide in the cause analysis of breeding failure is likely to be underestimated. During the breeding season of March to August 2019, we observed two cases of non-kin infanticide in Oriental Magpie Robins Copsychus saularis in nest boxes. The first incident occurred during the absence of the nesting male during the brooding period and in the sole presence of the female; another male entered the nest box and continuously attacked and pecked all four eight-day-old nestlings in the nest until they died. A second incident occurred in the presence of both parents, but during the feeding interval; a male perpetrator entered the nest box and pecked and pushed the single three-day-old nestling out of the box. The parents continued to carry food to the nest and tried to feed their nestling even after the latter had been killed. The parents were observed behaving anxiously once they detected no sign of activity from their nestling. We speculated that these examples of non-kin infanticide by conspecific Oriental Magpie Robin males could be attributed to competition for food resources or mates.","PeriodicalId":49009,"journal":{"name":"Ornithological Science","volume":"20 1","pages":"241 - 245"},"PeriodicalIF":0.6,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45499046","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}
Chinatsu Kando, N. Ota, K. Ono, M. Tsunokawa, Masahiro Niino, T. Tsuda, T. Shiina, J. Kulski, Yuki F. Kita, Shingo Suzuki
Abstract The Gentoo Penguins Pygoscelis papua has been classified into two subspecies, Northern P. papua papua and Southern P. papua ellsworthi. In Japan, where a breeding program exists for Gentoo Penguins, the Japanese Association of Zoos and Aquariums (JAZA) has recognized three categories of species in its pedigree ledger: Northern (from the islands of South Georgia), Southern (from the South Shetland Islands), and Unknown (when their origins are not clear). Phylogenetic analyses of the mitochondrial DNA (mtDNA) D-loop region of Gentoo Penguins in their natural habitat have differentiated them as belonging to the Kerguelen Islands (Indian Ocean), Falkland Islands (Atlantic Ocean), and South Georgia (Atlantic Ocean), and categorized some as Northern and others as Southern subspecies. However, the identification of a third subspecies has been suggested. Therefore, reclassification of captive Gentoo Penguins using phylogenetic analysis is necessary for domestic subspecies pedigree management. In this study, we determined five mtDNA haplotype sequences using seven Gentoo Penguins (considered morphologically as three Northern, three Southern, and one Unknown) and characterized their phylogenetic relationships among subspecies and among geographical distributions including 56 published mtDNA sequences. The phylogenetic tree showed three major lineages, Kerguelen Islands, Falkland Islands, and Scotia Arc/Antartica. The five haplotype sequences of the seven captive Gentoo Penguins were classified unexpectedly to one lineage, the Scotia Arc/Antartica, which contains the nucleotide sequences derived from Southern P. papua ellsworthi. Therefore, the mtDNA phylogeny of the seven captive penguins suggests that all captive Gentoo Penguins in Japan belong to the Southern subspecies. If so, then more comprehensive genetic testing of Gentoo Penguins in Japanese aquariums and zoos is required for the management of successful breeding programs.
{"title":"Subspecies Identification of Captive Gentoo Penguins in Japan, Using Mitochondrial DNA Phylogeny for Their Pedigree Management","authors":"Chinatsu Kando, N. Ota, K. Ono, M. Tsunokawa, Masahiro Niino, T. Tsuda, T. Shiina, J. Kulski, Yuki F. Kita, Shingo Suzuki","doi":"10.2326/osj.20.93","DOIUrl":"https://doi.org/10.2326/osj.20.93","url":null,"abstract":"Abstract The Gentoo Penguins Pygoscelis papua has been classified into two subspecies, Northern P. papua papua and Southern P. papua ellsworthi. In Japan, where a breeding program exists for Gentoo Penguins, the Japanese Association of Zoos and Aquariums (JAZA) has recognized three categories of species in its pedigree ledger: Northern (from the islands of South Georgia), Southern (from the South Shetland Islands), and Unknown (when their origins are not clear). Phylogenetic analyses of the mitochondrial DNA (mtDNA) D-loop region of Gentoo Penguins in their natural habitat have differentiated them as belonging to the Kerguelen Islands (Indian Ocean), Falkland Islands (Atlantic Ocean), and South Georgia (Atlantic Ocean), and categorized some as Northern and others as Southern subspecies. However, the identification of a third subspecies has been suggested. Therefore, reclassification of captive Gentoo Penguins using phylogenetic analysis is necessary for domestic subspecies pedigree management. In this study, we determined five mtDNA haplotype sequences using seven Gentoo Penguins (considered morphologically as three Northern, three Southern, and one Unknown) and characterized their phylogenetic relationships among subspecies and among geographical distributions including 56 published mtDNA sequences. The phylogenetic tree showed three major lineages, Kerguelen Islands, Falkland Islands, and Scotia Arc/Antartica. The five haplotype sequences of the seven captive Gentoo Penguins were classified unexpectedly to one lineage, the Scotia Arc/Antartica, which contains the nucleotide sequences derived from Southern P. papua ellsworthi. Therefore, the mtDNA phylogeny of the seven captive penguins suggests that all captive Gentoo Penguins in Japan belong to the Southern subspecies. If so, then more comprehensive genetic testing of Gentoo Penguins in Japanese aquariums and zoos is required for the management of successful breeding programs.","PeriodicalId":49009,"journal":{"name":"Ornithological Science","volume":"20 1","pages":"93 - 100"},"PeriodicalIF":0.6,"publicationDate":"2021-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48997718","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}
A. Sawada, T. Iwasaki, T. Matsuo, Kana Akatani, M. Takagi
Abstract One of the consequences of selections acting on body size is the difference in body size between the sexes or sexual size dimorphism. Although many hypotheses have been proposed for reversed sexual size dimorphism (RSD) in raptors, ornithologists have rarely paid attention to temporal aspects of RSD when testing their hypotheses. Because selection pressures may vary temporally, describing temporal variation in RSD is a first step towards understanding evolutionary mechanism which shape and maintain the dimorphism. Here, we describe RSD in the population of Ryukyu Scops Owls Otus elegans on Minami-daito Island using a dataset of the external measurements of 770 individuals obtained during a 17-year long-term population monitoring project. Females were larger than males in body mass, culmen length, bill depth, bill width, tail length and flattened wing length, whereas males were larger than females in tarsus and head lengths. Among these traits, the degree and direction of RSD of body mass, tarsus length, bill depth and flattened wing length varied across years. There were neither increasing nor decreasing trends in RSD. This is a rare study which addressed temporal variation in RSD in a raptor species.
{"title":"Reversed Sexual Size Dimorphism in the Ryukyu Scops Owl Otus elegans on Minami-Daito Island","authors":"A. Sawada, T. Iwasaki, T. Matsuo, Kana Akatani, M. Takagi","doi":"10.2326/osj.20.15","DOIUrl":"https://doi.org/10.2326/osj.20.15","url":null,"abstract":"Abstract One of the consequences of selections acting on body size is the difference in body size between the sexes or sexual size dimorphism. Although many hypotheses have been proposed for reversed sexual size dimorphism (RSD) in raptors, ornithologists have rarely paid attention to temporal aspects of RSD when testing their hypotheses. Because selection pressures may vary temporally, describing temporal variation in RSD is a first step towards understanding evolutionary mechanism which shape and maintain the dimorphism. Here, we describe RSD in the population of Ryukyu Scops Owls Otus elegans on Minami-daito Island using a dataset of the external measurements of 770 individuals obtained during a 17-year long-term population monitoring project. Females were larger than males in body mass, culmen length, bill depth, bill width, tail length and flattened wing length, whereas males were larger than females in tarsus and head lengths. Among these traits, the degree and direction of RSD of body mass, tarsus length, bill depth and flattened wing length varied across years. There were neither increasing nor decreasing trends in RSD. This is a rare study which addressed temporal variation in RSD in a raptor species.","PeriodicalId":49009,"journal":{"name":"Ornithological Science","volume":"20 1","pages":"15 - 26"},"PeriodicalIF":0.6,"publicationDate":"2021-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45454289","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}
Abstract Rice fields provide important inland stopover sites for migratory shorebirds. However, stopover duration and habitat use depend on the environmental conditions in the rice fields, which constantly change due to agricultural activities. This study determined the characteristics of habitat use in two shorebird species, the Wood Sandpiper Tringa glareola and Common Greenshank T. nebularia, in rice fields with different habitat conditions resulting from physical changes (field type: fields flooded after plowing, with high water levels after harrowing, or with low water levels after harrowing) and chemical changes (pesticide use: environmentally friendly or conventional farming) from agricultural activities around the time the migratory shorebirds arrive. The study was conducted during the spring stopover periods of these shorebird species in 2015 (May 2–20, 19 days) and 2016 (May 2–21, 20 days), during which we observed the characteristics of their habitat use and estimated the densities of potential prey. Both Wood Sandpiper and Common Greenshank were observed to use flooded fields with low water levels after harrowing. As for pesticide use, potential prey animals were most densely populated in environmentally friendly fields, for which only the large-bodied Common Greenshanks showed selection. This species-specific habitat use seems to be closely associated with body size-dependent prey availability and prey species selection. The small-bodied Wood Sandpiper was more affected by physical than chemical factors. These findings suggest that rice fields—major inland stopover sites for shorebirds—provide different habitats depending on agricultural activities. The study results also have practical implications for future improvement of inland shorebird habitat through efficient rice field management sensitive to the needs of migratory shorebirds.
{"title":"The Impact of Agricultural Activities on Habitat Use by the Wood Sandpiper and Common Greenshank in Rice Fields","authors":"G. Choi, H. Nam, S. Son, M. Do, Jeong-Chil Yoo","doi":"10.2326/osj.20.27","DOIUrl":"https://doi.org/10.2326/osj.20.27","url":null,"abstract":"Abstract Rice fields provide important inland stopover sites for migratory shorebirds. However, stopover duration and habitat use depend on the environmental conditions in the rice fields, which constantly change due to agricultural activities. This study determined the characteristics of habitat use in two shorebird species, the Wood Sandpiper Tringa glareola and Common Greenshank T. nebularia, in rice fields with different habitat conditions resulting from physical changes (field type: fields flooded after plowing, with high water levels after harrowing, or with low water levels after harrowing) and chemical changes (pesticide use: environmentally friendly or conventional farming) from agricultural activities around the time the migratory shorebirds arrive. The study was conducted during the spring stopover periods of these shorebird species in 2015 (May 2–20, 19 days) and 2016 (May 2–21, 20 days), during which we observed the characteristics of their habitat use and estimated the densities of potential prey. Both Wood Sandpiper and Common Greenshank were observed to use flooded fields with low water levels after harrowing. As for pesticide use, potential prey animals were most densely populated in environmentally friendly fields, for which only the large-bodied Common Greenshanks showed selection. This species-specific habitat use seems to be closely associated with body size-dependent prey availability and prey species selection. The small-bodied Wood Sandpiper was more affected by physical than chemical factors. These findings suggest that rice fields—major inland stopover sites for shorebirds—provide different habitats depending on agricultural activities. The study results also have practical implications for future improvement of inland shorebird habitat through efficient rice field management sensitive to the needs of migratory shorebirds.","PeriodicalId":49009,"journal":{"name":"Ornithological Science","volume":"20 1","pages":"27 - 37"},"PeriodicalIF":0.6,"publicationDate":"2021-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47002844","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}
Abstract In Malaysia, multiple land use by humans has caused substantial losses of wetland ecosystems, and shrinkage of the populations, habitat and food bases of avian species. However, studies of avian populations, especially of waterbirds, is important, allowing us to understand the complexity of the wetland ecosystem structure, and also develop appropriate management techniques with robust monitoring tools to ensure the ecological sustainability of wetlands. This study aimed to determine the eco-climatic factors influencing the occurrence of waterbirds and to develop habitat suitability models for thePaya Indah (PIW) and Putrajaya wetlands (PW), Malaysia. A distance sampling point count technique using stratified random design was employed to survey the wetlands from November 2016 to January 2019. A total of 57 sampling points at 14 lakes at PIW and 54 sampling points at 24 lakes at PW were chosen. An automatic linear modelling algorithm and geographic information systems were employed to compute the importance ratios of 17 eco-climatic factors (hydrology 9; climate 5; waterscape 1 and landscape 2). The results revealed that all individual and estimated indices for observed waterbirds were significant. The automatic linear modelling algorithm results for PIW waterbirds also showed that the maximum and minimum weights of the factors were land cover and water dissolved oxygen, while in PW they were atmospheric pressure and Normalized Difference Water Index (NDWI). The maximum and minimum weights of the factors for waterbirds in PIW were water turbidity and electrical conductivity, while at PW they were atmospheric pressure and six water parameters. Large areas of Putrajaya Wetland were classified as more suitable for waterbirds than Paya Indah Wetland due to the favourable water pH, atmospheric pressure and land cover (forage availability). Thus, the models' adoption as a management tool can help in the maintenance of the wetlands' habitat quality and management effectiveness of waterbird species.
{"title":"Environmental Factors and Spatial Heterogeneity Affect Occupancy Estimates of Waterbirds in Peninsular Malaysia","authors":"C. O. Martins, O. E. Olaniyi, M. Zakaria","doi":"10.2326/osj.20.39","DOIUrl":"https://doi.org/10.2326/osj.20.39","url":null,"abstract":"Abstract In Malaysia, multiple land use by humans has caused substantial losses of wetland ecosystems, and shrinkage of the populations, habitat and food bases of avian species. However, studies of avian populations, especially of waterbirds, is important, allowing us to understand the complexity of the wetland ecosystem structure, and also develop appropriate management techniques with robust monitoring tools to ensure the ecological sustainability of wetlands. This study aimed to determine the eco-climatic factors influencing the occurrence of waterbirds and to develop habitat suitability models for thePaya Indah (PIW) and Putrajaya wetlands (PW), Malaysia. A distance sampling point count technique using stratified random design was employed to survey the wetlands from November 2016 to January 2019. A total of 57 sampling points at 14 lakes at PIW and 54 sampling points at 24 lakes at PW were chosen. An automatic linear modelling algorithm and geographic information systems were employed to compute the importance ratios of 17 eco-climatic factors (hydrology 9; climate 5; waterscape 1 and landscape 2). The results revealed that all individual and estimated indices for observed waterbirds were significant. The automatic linear modelling algorithm results for PIW waterbirds also showed that the maximum and minimum weights of the factors were land cover and water dissolved oxygen, while in PW they were atmospheric pressure and Normalized Difference Water Index (NDWI). The maximum and minimum weights of the factors for waterbirds in PIW were water turbidity and electrical conductivity, while at PW they were atmospheric pressure and six water parameters. Large areas of Putrajaya Wetland were classified as more suitable for waterbirds than Paya Indah Wetland due to the favourable water pH, atmospheric pressure and land cover (forage availability). Thus, the models' adoption as a management tool can help in the maintenance of the wetlands' habitat quality and management effectiveness of waterbird species.","PeriodicalId":49009,"journal":{"name":"Ornithological Science","volume":"20 1","pages":"39 - 55"},"PeriodicalIF":0.6,"publicationDate":"2021-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48237915","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}
Abstract Research into the breeding ecology of birds is key to understanding the evolution of life-history traits and developing effective species conservation measures. We studied the breeding ecology of the Crested Myna Acridotheres cristatellus on tropical Hainan Island, China, throughout the breeding season from March to August in 2018 and 2019. Parents Crested Myna build disk-shaped nests together and take turns to incubate their eggs and feed their nestlings, with a nestling period of 18–22 days. Eggs were pure blue-green, and the clutch sizes were 3–6 eggs (averaging 4). Egg mass, egg size, and egg volume were 6.78±0.50 g, 28.74±1.20 mm×21.13±0.53 mm, and 6.56±0.50 cm3, respectively (N=274). Egg-laying mainly occurred between 0700 to 1000, and the average time for laying one egg was 172.36±28.29 s (N=11). Feeding frequency during the mid-nestling period was significantly higher than in the early periods (N=55). The Crested Myna population on tropical Hainan nested earlier, laid eggs earlier and had a longer breeding period than populations in the temperate zone.
{"title":"The Breeding Ecology of the Crested Myna Acridotheres cristatellus on Tropical Hainan Island","authors":"Jinmei Liu, W. Liang","doi":"10.2326/osj.20.83","DOIUrl":"https://doi.org/10.2326/osj.20.83","url":null,"abstract":"Abstract Research into the breeding ecology of birds is key to understanding the evolution of life-history traits and developing effective species conservation measures. We studied the breeding ecology of the Crested Myna Acridotheres cristatellus on tropical Hainan Island, China, throughout the breeding season from March to August in 2018 and 2019. Parents Crested Myna build disk-shaped nests together and take turns to incubate their eggs and feed their nestlings, with a nestling period of 18–22 days. Eggs were pure blue-green, and the clutch sizes were 3–6 eggs (averaging 4). Egg mass, egg size, and egg volume were 6.78±0.50 g, 28.74±1.20 mm×21.13±0.53 mm, and 6.56±0.50 cm3, respectively (N=274). Egg-laying mainly occurred between 0700 to 1000, and the average time for laying one egg was 172.36±28.29 s (N=11). Feeding frequency during the mid-nestling period was significantly higher than in the early periods (N=55). The Crested Myna population on tropical Hainan nested earlier, laid eggs earlier and had a longer breeding period than populations in the temperate zone.","PeriodicalId":49009,"journal":{"name":"Ornithological Science","volume":"20 1","pages":"83 - 92"},"PeriodicalIF":0.6,"publicationDate":"2021-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46544293","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}
Katsura Mikami, Noriyuki M. Yamaguchi, R. Noske, Kazuhiro Eguchi
Abstract We studied the pattern of acquisition of breeding positions among helpers in a population of Grey-crowned Babblers Pomatostomus temporalis rubecula in the monsoon tropics of northwestern Australia, using both behavioural and molecular data. In particular, we focused on sex differences, kinship, and their interactions among emigrating helpers. Moreover, we also considered whether intergroup movement and extra-pair mating contributed to incest avoidance in our population. The advantage of this material is that there are previous studies of populations in different regions, and the comparison of the results may provide a better understanding of ecological factors driving helping behaviour in cooperative breeding. Three options for a mature helper to acquire a breeding position were observed: establishing a new territory, emigrating to an existing territory, or waiting in the natal territory for a breeding vacancy. In many cases, male helpers took the third option, while female helpers took the second one. Our population of Grey-crowned Babblers seemed not to be actively avoiding incest. Female helpers tended to disperse from natal groups more than males, but neither intergroup movements nor extra-pair mating were effective in avoiding incestuous breeding. In some groups, dominant breeders were closely related to each other. The frequency of extra-pair mating in our population was similar to that of the New South Wales population previously studied, but dispersal distances were twice as great. The two populations also differ in mean clutch size and group size. Such variation in life history characteristics among different populations of cooperatively breeding species has received little attention, but has the potential to explain how cooperative breeding systems are modified by environmental factors.
{"title":"Male and Female Helpers of Grey-Crowned Babblers Pomatostomus temporalis rubecula Acquire Breeding Positions in Different Ways, and don't Avoid Incest","authors":"Katsura Mikami, Noriyuki M. Yamaguchi, R. Noske, Kazuhiro Eguchi","doi":"10.2326/osj.20.3","DOIUrl":"https://doi.org/10.2326/osj.20.3","url":null,"abstract":"Abstract We studied the pattern of acquisition of breeding positions among helpers in a population of Grey-crowned Babblers Pomatostomus temporalis rubecula in the monsoon tropics of northwestern Australia, using both behavioural and molecular data. In particular, we focused on sex differences, kinship, and their interactions among emigrating helpers. Moreover, we also considered whether intergroup movement and extra-pair mating contributed to incest avoidance in our population. The advantage of this material is that there are previous studies of populations in different regions, and the comparison of the results may provide a better understanding of ecological factors driving helping behaviour in cooperative breeding. Three options for a mature helper to acquire a breeding position were observed: establishing a new territory, emigrating to an existing territory, or waiting in the natal territory for a breeding vacancy. In many cases, male helpers took the third option, while female helpers took the second one. Our population of Grey-crowned Babblers seemed not to be actively avoiding incest. Female helpers tended to disperse from natal groups more than males, but neither intergroup movements nor extra-pair mating were effective in avoiding incestuous breeding. In some groups, dominant breeders were closely related to each other. The frequency of extra-pair mating in our population was similar to that of the New South Wales population previously studied, but dispersal distances were twice as great. The two populations also differ in mean clutch size and group size. Such variation in life history characteristics among different populations of cooperatively breeding species has received little attention, but has the potential to explain how cooperative breeding systems are modified by environmental factors.","PeriodicalId":49009,"journal":{"name":"Ornithological Science","volume":"20 1","pages":"3 - 13"},"PeriodicalIF":0.6,"publicationDate":"2021-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46602232","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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