The breeding biology of a captive, isolated population of Dalmatian Pelicans (Pelecanus crispus) at theShanghaiZoo,China, was studied from 2007 to 2019. The breeding age of the Dalmatian Pelicans was estimated at thre...The breeding biology of a captive, isolated population of Dalmatian Pelicans (Pelecanus crispus) at theShanghaiZoo,China, was studied from 2007 to 2019. The breeding age of the Dalmatian Pelicans was estimated at three to four years old, and they started breeding in late October or early November. The clutch size varied between one and two eggs per nest, and the eggs were 83.2 ±4.8 mmin length, 55.6 ±2.9 mmin breadth and 136.1 ±21.5 gin weight. The fertility fluctuated slightly, with an average rate of 38.7% ± 9.7%, but remained consistently low. The survival rate of chicks fluctuated substantially from 0% to 100%, with an average survival rate of 68.6% ± 27.6%. The averaged values of observed heterozygosity, expected heterozygosity and polymorphism information content were 0.468, 0.465 and 0.446, respectively. It indicated that the population had a low heterozygosity and genetic diversity. There was a significant change in the breeding index compared to that recorded 40 years ago, which indicates that inbreeding depression has occurred in this small, isolated, captive population of Dalmatian Pelicans. These results can be used to improve management of Dalmatian Pelicans in captivity.展开更多
In order to tease apart proximate vs. ultimate sources of variation in reproductive strategy, studies have increasingly focused on populations rather than species as the unit of interest. The reproductive parameters o...In order to tease apart proximate vs. ultimate sources of variation in reproductive strategy, studies have increasingly focused on populations rather than species as the unit of interest. The reproductive parameters of Phrynocephalus przewalskii （Agamidae） in different populations within the same phylogenetic clade were compared in this study. Female SVL, clutch size, egg volume and clutch volume varied significantly among populations. With increase in latitude, clutch size increased, while egg size decreased. Relatively fewer but larger eggs were produced with increasing of population density. Food availability had positive effects on clutch size, but no effect on egg size. Our result indicated that latitude, food availability and population density may be the proximate factors affecting the reproductive parameters ofP. przewalskii.展开更多
Although shifts in life-history traits of insular vertebrates, as compared with mainland populations, have been observed in many taxa, few studies have examined the relationships among individual life-history traits o...Although shifts in life-history traits of insular vertebrates, as compared with mainland populations, have been observed in many taxa, few studies have examined the relationships among individual life-history traits on islands. Lifehistory theory also predicts that there is a trade-off between body size and reproductive effort, and between egg size and clutch size. We surveyed the rice frog, Fejervarya limnocharis, on 20 islands within the Zhoushan Archipelago and two nearby sites on the mainland of China to compare differences in life-history traits and to explore relationships among those traits. Rice frog females reached a greater body size on half of the smaller islands among the total 20 surveyed islands, and larger egg size, decreased clutch size and reduced reproductive effort on most of the islands when compared to the two mainland sites. Insular body size was negatively correlated with reproductive effort. There was a negative correlation between egg size and clutch size. Results suggest that life-history theory provides a good explanation for co-variation between body size and reproductive effort, and between egg size and clutch size in rice frogs on the islands.展开更多
基金全球环境基金会/世界银行项目(GEF-MSP grant No.TF051795)云南省发展和改革委员会项目(滇中主要湖泊土著特有鱼类迁地保育人工繁殖与持续利用试验示范)+2 种基金中国科学院西部之光项目(292006312D11033)云南省科技厅社会发展科技计划项目(2008CA001)国家重点基础研究发展计划项目(2007CB411600)
文摘The breeding biology of a captive, isolated population of Dalmatian Pelicans (Pelecanus crispus) at theShanghaiZoo,China, was studied from 2007 to 2019. The breeding age of the Dalmatian Pelicans was estimated at three to four years old, and they started breeding in late October or early November. The clutch size varied between one and two eggs per nest, and the eggs were 83.2 ±4.8 mmin length, 55.6 ±2.9 mmin breadth and 136.1 ±21.5 gin weight. The fertility fluctuated slightly, with an average rate of 38.7% ± 9.7%, but remained consistently low. The survival rate of chicks fluctuated substantially from 0% to 100%, with an average survival rate of 68.6% ± 27.6%. The averaged values of observed heterozygosity, expected heterozygosity and polymorphism information content were 0.468, 0.465 and 0.446, respectively. It indicated that the population had a low heterozygosity and genetic diversity. There was a significant change in the breeding index compared to that recorded 40 years ago, which indicates that inbreeding depression has occurred in this small, isolated, captive population of Dalmatian Pelicans. These results can be used to improve management of Dalmatian Pelicans in captivity.
文摘In order to tease apart proximate vs. ultimate sources of variation in reproductive strategy, studies have increasingly focused on populations rather than species as the unit of interest. The reproductive parameters of Phrynocephalus przewalskii （Agamidae） in different populations within the same phylogenetic clade were compared in this study. Female SVL, clutch size, egg volume and clutch volume varied significantly among populations. With increase in latitude, clutch size increased, while egg size decreased. Relatively fewer but larger eggs were produced with increasing of population density. Food availability had positive effects on clutch size, but no effect on egg size. Our result indicated that latitude, food availability and population density may be the proximate factors affecting the reproductive parameters ofP. przewalskii.
基金supported by the grant from the"973"Program of China(No.2007CB411600)the Chinese Academy of Sciences(CAS)(No.kscx2-yw-z-1021)the"Xi Bu Zhi Guang"Program of CAS(No.XBBS201102)
文摘Although shifts in life-history traits of insular vertebrates, as compared with mainland populations, have been observed in many taxa, few studies have examined the relationships among individual life-history traits on islands. Lifehistory theory also predicts that there is a trade-off between body size and reproductive effort, and between egg size and clutch size. We surveyed the rice frog, Fejervarya limnocharis, on 20 islands within the Zhoushan Archipelago and two nearby sites on the mainland of China to compare differences in life-history traits and to explore relationships among those traits. Rice frog females reached a greater body size on half of the smaller islands among the total 20 surveyed islands, and larger egg size, decreased clutch size and reduced reproductive effort on most of the islands when compared to the two mainland sites. Insular body size was negatively correlated with reproductive effort. There was a negative correlation between egg size and clutch size. Results suggest that life-history theory provides a good explanation for co-variation between body size and reproductive effort, and between egg size and clutch size in rice frogs on the islands.
