Geese have undergone significant changes in their distribution and population size due to human-induced impacts.To improve our understanding of the two main geese populations in East Asia—Greater White-fronted(Anser ...Geese have undergone significant changes in their distribution and population size due to human-induced impacts.To improve our understanding of the two main geese populations in East Asia—Greater White-fronted(Anser albifrons;GWFG)and Bean Geese(Anser fabalis sensu lato;BEAG),which includes the Tundra A.f.serrirostris(TDBG)and Taiga Bean Geese A.f.middendorffii(TGBG),this study estimated their long-and short-term trends and the migration strategies based on their distribution during the migratory and wintering seasons,using nationwide census data collected over 24 years in South Korea.The TRIM(TRends and Indices for Monitoring data)analysis supported a robust long-term population increase since 1999,recently stabilizing around 150,000 individuals in GWFG and 100,000 in TDBG,respectively.But TGBG stabilized at around 7000 with no significant change of population over time.The shorter-term trends within a season suggested that wintering populations of GWFG and TDBG in China might stop over in Korea in their autumn migration before their sea-crossing,evidenced by the large congregation near the Yellow Sea coast followed by a gradual decrease.In contrast to autumn,there was no similar peak in spring migration,suggesting the potential for elliptical migration of some populations around the Yellow Sea.Our findings indicate a growing East Asian population and imply one of the migration strategies of the Greater White-fronted and Tundra Bean Geese.By collaborating with recent tracking data,long-term monitoring efforts could offer more detailed insights into population trends and migration strategies,thereby contributing to the effective management and conservation of goose species in East Asia.展开更多
A longstanding suggestion posits that parents prefer to match nest volume and clutch size （clutch volume）, but few studies have tested this in colonial seabirds that nest in the open. Here, we demonstrate the effect...A longstanding suggestion posits that parents prefer to match nest volume and clutch size （clutch volume）, but few studies have tested this in colonial seabirds that nest in the open. Here, we demonstrate the effects of nest-clutch volume matching on egg survival, hatching, and fledgling success in black-tailed gulls Larus crassirostris on Hongdo Island, Korea. We show that the volume mismatch, defined as the difference between nest volume and total egg volume （the sum of all eggs＇ volume in the clutch）, was positively related to egg and chick mortality caused by predation, but was not significantly related to hatching success incurred by insulation during the incubation period. Although nest volume was negatively related to laying date, we found that the mismatch was positively related to laying date. Our results support the claim that well-matched nest-clutch volume may contribute to survival of eggs and chicks, and ultimately breeding success.展开更多
基金supported by“The analysis of biogeographical and phenological migration pattern of birds as vectors of avian influenza(0525–202300058)”of the Korea Environment Institute“Long-term change of waterbird population in climate change(NIBR202318101,NIBR202416101)”of the National Institute of Biological Resources in South Korea.
文摘Geese have undergone significant changes in their distribution and population size due to human-induced impacts.To improve our understanding of the two main geese populations in East Asia—Greater White-fronted(Anser albifrons;GWFG)and Bean Geese(Anser fabalis sensu lato;BEAG),which includes the Tundra A.f.serrirostris(TDBG)and Taiga Bean Geese A.f.middendorffii(TGBG),this study estimated their long-and short-term trends and the migration strategies based on their distribution during the migratory and wintering seasons,using nationwide census data collected over 24 years in South Korea.The TRIM(TRends and Indices for Monitoring data)analysis supported a robust long-term population increase since 1999,recently stabilizing around 150,000 individuals in GWFG and 100,000 in TDBG,respectively.But TGBG stabilized at around 7000 with no significant change of population over time.The shorter-term trends within a season suggested that wintering populations of GWFG and TDBG in China might stop over in Korea in their autumn migration before their sea-crossing,evidenced by the large congregation near the Yellow Sea coast followed by a gradual decrease.In contrast to autumn,there was no similar peak in spring migration,suggesting the potential for elliptical migration of some populations around the Yellow Sea.Our findings indicate a growing East Asian population and imply one of the migration strategies of the Greater White-fronted and Tundra Bean Geese.By collaborating with recent tracking data,long-term monitoring efforts could offer more detailed insights into population trends and migration strategies,thereby contributing to the effective management and conservation of goose species in East Asia.
文摘A longstanding suggestion posits that parents prefer to match nest volume and clutch size （clutch volume）, but few studies have tested this in colonial seabirds that nest in the open. Here, we demonstrate the effects of nest-clutch volume matching on egg survival, hatching, and fledgling success in black-tailed gulls Larus crassirostris on Hongdo Island, Korea. We show that the volume mismatch, defined as the difference between nest volume and total egg volume （the sum of all eggs＇ volume in the clutch）, was positively related to egg and chick mortality caused by predation, but was not significantly related to hatching success incurred by insulation during the incubation period. Although nest volume was negatively related to laying date, we found that the mismatch was positively related to laying date. Our results support the claim that well-matched nest-clutch volume may contribute to survival of eggs and chicks, and ultimately breeding success.
