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Variation in egg and clutch size of the Black Redstart(Phoenicurus ochruros) at the northeastern edge of the Qinghai-Tibetan Plateau

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Chinese Birds 2016年第4期7卷 218-223页

作者： Sen Song Jiani Chen Bo Jiang Naifa Liu School of Life Sciences Lanzhou University

Background: In birds, the trade-off between the quality and number of nestlings is one of the most important theories of the evolution of life history of birds, which is closely related with climate. We investigated variation in egg and clutch size of the Black Redstart(Phoenicurus ochruros) on the northeastern edge of the Qinghai-Tibetan Plateau in order to explore and test the relation between egg size and clutch size and the rules governing the variation in these two components with climate ***: We monitored each located nest daily to determine the exact laying order of the eggs and measured their sizes. The variations in egg volume and clutch size between 2008 and 2009 were studied by independent sample t tests. The difference in egg volume in the sequence of the laying order was tested by Kendall's W test and we employed Pearson correlations to investigate the relation between egg size and laying order. All statistical analyses were performed with IBM SPSS Statistics, version 19.0Results: In 2008, the mean egg volume of the Black Redstart was 2.40 and clutch size wer± 0.20 cm^3(n e 2.26 = 50), and the mean clutch size 4.90 ± 0.57(n = 11). In 2009, the mean egg volumeation between eg± 0.18 cm^3(n g size and layin= 74) and 5.20 g order(r ± 0.26(n = 15) respectively. We found a significantly positive correl, while egg size was strongly and negatively correlated with clutch size(r = 0.397, p = 0.030) smaller eggs but a larger clutch in a brood in a resource-rich year, w= h-0.274, p ereas large= 0.002). Black Redstarts tend to layr eggs but smaller clutches are produced in a harsh ***: The Black Redstart adopted a "brood survival strategy" to ensure that more offspring could survive. The Black Redstart' trade-off in egg volume and clutch size would guarantee that it will gain maximum benefit in any case.

关键词： egg size Clutch size Laying order Trade-off Black Redstart Phoenicurus ochruros

Behavioral and physiological flexibility are used by birds to manage energy and support investment in the early stages of reproduction

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Current Zoology 2010年第6期56卷 767-792页

作者： Franois VZINA Katrina G. SALVANTE Département de Biologie chimie et géographieGroupe de recherche sur les environnements nordiques BORASUniversité du Québec à Rimouski Department of Biological Sciences Simon Fraser University

Interest in phenotypic flexibility has increased dramatically over the last decade, but flexibility during reproduction has received relatively little attention from avian scientists, despite its possible impact on fitness. Because most avian species maintain atrophied reproductive organs when not active, reproduction in birds requires major tissue remodeling in preparation for breeding. Females undergo rapid （days） recrudescence and regression of their reproductive organs at each breeding attempt, while males grow their organs ahead of time at a much slower rate （weeks） and may maintain them at maximal size throughout the breeding season. Reproduction is associated with significant metabolic costs. egg production leads to a 22%-27% increase in resting metabolic rate （RMR） over non-reproductive values. This is partly due to the activity of the oviduct, an organ that may allow females to adjust reproductive investment by modulating egg size and quality. In males, gonadal recrudescence may lead to a 30% increase in RMR, but the data are inconsistent and general conclusions regarding energetic costs of reproduction in males will require more research. Recent studies on captive female zebra finches describe the impacts of these costs on daily energy budgets and highlight the strategies used by birds to maintain their investment in reproduction when energy is limited. Whenever possible, birds use behavioral flexibility as a first means of saving energy. Decreasing locomotor activity saves energy during challenges such as egg production or exposure to cold temperatures and is an efficient way to buffer variation in individual daily energy budgets. However, when behavioral flexibility is not possible, birds must rely on flexibility at the physiological level to meet energy demands. In zebra finches breeding in the cold, this results in a reduced pace of laying, likely due to down-regulation of both reproductive and non-reproductive function, allowing females to defend mini

关键词： Phenotypic plasticity Phenotypic flexibility BMR Energy budget Organ egg size Physiological tradeoff Fitness

egg investment strategies adopted by a desertic passerine, the Saxaul Sparrow(Passer ammodendri)

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Avian Research 2020年第2期11卷 166-173页

作者： Xinkang Bao Wei Zhao Fangqing Liu Jianliang Li Donghui Ma Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution School of Life SciencesLanzhou UniversityLanzhou 730000China Key Laboratory of Sichuan Institute for Protecting Endangered Birds in the Southwest Mountains College of Life SciencesLeshan Normal UniversityLeshan 614000China

Background:As one of the reproductive strategies adopted by bird species,variation in investment in egg production and its influencing factors are important and well-studied *** changes in egg size associated with laying order may reflect a strategy of"brood survival"or"brood reduction"adopted by female birds in different ***:We conducted field studies on the breeding parameters of the Saxaul Sparrow(Passer ammodendri)in Gansu Province,China from 2010 to 2017,to clarify the factors affecting the egg investment and reproductive performance of this passerine ***:Our results revealed significant differences in clutch size,egg size and the fledging rate between the first and second brood of Saxaul Sparrows and suggested that this typical desert species allocates more breeding resources to the more favourable second brood period,leading to greater reproductive *** body size presented a positive relationship with egg size,and male body size presented positive relationships with clutch size and *** females that started their clutches later laid more eggs,and hatchability and the fledging rate also increased with a later laying date in the first brood *** successive eggs laid within the 5-egg clutches(the most frequent clutch size),egg size increased for the first three eggs and then significantly ***:Our results indicate that female Saxaul Sparrows increased egg investment because of good quality of paired males and good environmental *** intraclutch variation of egg size suggests that this species inhabiting an arid environment adopts a"brood reduction"strategy.

关键词： Brood reduction strategy Clutch size egg size Fledging rate Hatchability Reproductive strategy Saxaul Sparrow

The breeding biology of endemic Spectacled Parrotbill(Sinosuthora conspicillatus) in Lianhuashan National Nature Reserve, Gansu Province, China

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Avian Research 2018年第1期9卷 43-48页

作者： Lijun Chen Lei Zhu Yunbiao Hu Pengfei Liu Nan Lyu Yuehua Sun Key Laboratory of Animal Ecology and Conservation Biology Institute of Zoology Chinese Academy of Sciences Beijing 100101 China State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of Zoology Chinese Academy of Sciences Beijing 100101 China Chengdu Bird Watching Society Chengdu 610041 China

Background: Life history traits play critical roles in population survival and *** information should be particularly detailed in order to provide significant insights into the population status and the evolution of other *** our knowledge, there is still no information about the breeding biology of Spectacled Parrotbill(Sinosuthora conspicillatus), an endemic parrotbill in ***: We searched the nests, checked all nests found and recorded the information of eggs, nestlings and nest sites of the Spectacled Parrotbill from 2013 to 2015 at Lianhuashan National Nature Reserve in Gansu Province, ***: A total of 16 nests were *** trees were artificial young spruces and *** nest height was 0.89 ± 0.47 m(n = 16) above the ground *** nests were cup-shaped and constructed using leaves, fine strips of barks and grasses by both *** mean clutch size was 4.42 ± 0.79(n = 12).The eggs were oval in pale blue without speckles, and the mean egg mass was 1.25 ± 0.07 g(n = 27).The egg length was 15.56 ± 0.46 mm(n = 27) and the width was 12.46 ± 0.29 mm(n = 27).Incubation period was 13 days and nestling period was 13–14 *** breeding success rate was 46%, and among those failed nest, 71% were depredated and 29% were ***: Detailed life history information about parrotbill is still *** breeding biology of Spectacled Parrotbill reported in the present study should be helpful for further research about population, breeding behavior and conservation of this bird.

关键词： Reproduction Paradoxornithidae Nest description Brood size egg size Nest survival

Elevational Variation in Reproductive Strategy of a Widespread Lizard:High-Elevation Females Lay Fewer but Larger eggs

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Asian Herpetological Research 2022年第3期13卷 198-204页

作者： Gideon Gywa DEME Xin HAO Liang MA Baojun SUN Weiguo DU Key Laboratory of Animal Ecology and Conservation Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100039China College of Forestry Hainan UniversityHaikou 570228HainanChina

Identifying how reproductive strategies such as the trade-off between clutch size versus egg mass vary with elevational gradients is essential for our understanding of life-history *** studied lacertid lizards(Eremias argus)in China,from six populations at different altitudes,to assess elevational variation in reproductive *** found significant between-population variation in maternal body size and clutch mass,but these variations were not explained by elevational ***,high-elevation females tended to produce smaller clutches of larger eggs compared with their low-elevation counterparts,demonstrating an elevational change in the trade-off between egg size and *** egg size-number trade-off is a reproductive strategy that may favor large offspring,better enabling them to survive severe and unpredictable environments found at high elevations.

关键词： between-population variation clutch size egg size elevational gradient Eremiasargus local adaptation reproductive output

High Altitude Frogs (Rana kukonoris) Adopt a Diversified Bethedging Strategy in the Face of Environmental Unpredictability

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Asian Herpetological Research 2018年第1期9卷 43-49页

作者： Wei CHEN Liqing PENG Lichun JIANG David A.PIKE Christopher R.FRIESEN Gregory BROWN Ecological Security and Protection Key Laboratory of Sichuan Province Mianyang Normal University Department of Biology Rhodes College School of Life and Environmental Sciences University of Sydney

Environmental unpredictability can influence strategies of maternal investment among eggs within a clutch. Models predict that breeding females should adopt a diversified bet-hedging strategy in unpredictable environments, but empirical field evidence from Asia is scarce. Here we tested this hypothesis by exploring spatial patterns in egg size along an altitudinal gradient in a frog species （Rana kukunoris） inhabiting the Tibetan Plateau. Within-clutch variability in egg size increased as the environment became variable （e.g., lower mean monthly temperature and mean monthly rainfall at higher altitudes）, and populations in environments with more unpredictable rainfall produced eggs that were smaller and more variable in size. We provide support for a diversified bet-hedging strategy in high-altitude environments, which experience dynamic weather patterns and therefore are of unpredictable environmental quality. This strategy may be an adaptive response to lower environmental quality and higher unpredictable environmental variance. Such a strategy should increase the likelihood of breeding success and maximize maternal lifetime fitness by producing offspring that are adapted to current environmental conditions. We speculate that in high-altitude environments prone to physical disturbance, breeding females are unable to consistently produce the optimal egg size due to physiological constraints imposed by environmental conditions （e.g., duration of the active season, food availability）. Species and populations whose breeding strategies are adapted to cope with uncertain environmental conditions by adjusting offspring size and therefore quality show a remarkable degree of ability to cope with future climatic changes.

关键词： altitude bet-hedging strategy environmental quality egg size within-clutch variation unpredictable environment

Reproductive traits of the gray ratsnake Ptyas korros from three geographically distinct populations

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Current Zoology 2012年第6期58卷 820-827页

作者： Long-Hui LIN Fei MAO Ce CHEN Xiang JI Hangzhou Key Laboratory for Animal Adaptation and Evolution School of Life SciencesHangzhou Normal UniversityHangzhou 310036ZhejiangChina Jiangsu Key Laboratory for Biodiversity and Biotechnology College of Life SciencesNanjing Normal UniversityNanjing 210046JiangsuChina

Abstract We collected gravid gray rat snakes Ptyas korros from three geographically distinct populations in China, Chenzhou （CZ）, Jiangshan （JS） and Dinghai （DH）, to study geographical variation in female reproductive traits. egg-laying dates differed among the three populations such that at the most northern latitude egg-laying was latest, and earliest at the most southern latitutde. Clutch size, clutch mass, egg mass, egg shape, within clutch variability in egg sizes and relative clutch mass differed among the three populations, whereas post-oviposition body mass did not. Except for egg-laying date, none of the traits examined varied in a geographically continuous trend. CZ and DH females, although separated by a distance of approximately 1100 km as the crow flies, were similar in nearly all traits examined. JS females were distinguished from CZ and DH females by their higher fecundity （clutch size）, greater reproductive output （clutch mass） and more rounded eggs. Our data do not validate the prediction that larger offspring should be produced in colder localities. The absence of an egg size-number trade-off in each of the three populations presumably suggests that P. korros is among species where eggs are well optimized for size within a population.

关键词： Colubridae Life-history Reproductive output egg size Clutch size Geographical variation egg-laying date

Covariation in Insular Life-history Traits of the Rice Frog(Fejervarya limnocharis)in Eastern China

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Asian Herpetological Research 2013年第1期4卷 28-35页

作者： Feng XU Gregory H.ADLER Yiming LI Key Laboratory of Animal Ecology and Conservation Biology Institute of ZoologyChinese Academy of Sciences Key Laboratory of Biogeography and Bioresource in Arid Land Xinjiang Institute of Ecology and GeographyChinese Academy of Sciences Department of Biology and Microbiology University of Wisconsin-Oshkosh

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.

关键词： island syndrome life-history traits trade-off body size egg size clutch size reproductive effort

Geographical variation in reproductive traits and trade-offs between size and number of eggs in the king ratsnake,Elaphe carinata

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Geographical variation in reproductive traits and trade-offs...