{"title":"南非鸟岛繁殖的非洲企鹅斯芬克斯的巢小气候和热应激","authors":"S. Welman, L. Pichegru","doi":"10.1017/S0959270922000351","DOIUrl":null,"url":null,"abstract":"Summary Low-latitude penguins naturally breed in burrows dug in guano. This affords them a buffered environment that remains cool and humid, reducing the risk of hyperthermia while on land. As a conservation strategy, several versions of artificial housing units have been trialled at various breeding sites of African Penguins (Spheniscus demersus) around South Africa, where former guano exploitation forced many penguins to breed in exposed surface nests. While some units yielded a positive effect on breeding success by providing protection against predation, none of them have effectively mitigated the risk of heat stress in penguins or their eggs. Here, we investigated the microclimate of a recent double-layered design of ceramic artificial nests and compared that to natural burrows, exposed surface nests, and commonly used cement pipe nests, in austral summer 2021 on Bird Island, South Africa. We also recorded penguin behaviour during the hottest period at each of these nest types using remote camera traps to determine the onset of heat stress (panting). Double-layered ceramic nests out-performed all other nest types, including natural burrows, by remaining cooler throughout the day, with temperatures never exceeding 36.7°C. By contrast, all other nest types had multiple episodes where temperatures exceeded 40°C. Double-layered ceramic nests also maintained constant levels of high humidity (relative humidity [RH] >70%) throughout our study, whereas low humidity levels were observed in surface nests (RH ≈ 60%) and cement nests (RH <50%) during midday heat. We observed penguins panting at temperatures of 25°C in nest boxes, and at 22°C in exposed surface nests. This suggests that heat stress in African Penguins may occur much sooner than anticipated and that they are particularly vulnerable to hyperthermia as climate change-related global warming progresses. Fortunately, we are encouraged by the capacity of double-layered ceramic nest boxes to buffer environmental extremes and maintain suitable breeding conditions.","PeriodicalId":9275,"journal":{"name":"Bird Conservation International","volume":" ","pages":""},"PeriodicalIF":1.5000,"publicationDate":"2022-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":"{\"title\":\"Nest microclimate and heat stress in African Penguins Spheniscus demersus breeding on Bird Island, South Africa\",\"authors\":\"S. Welman, L. Pichegru\",\"doi\":\"10.1017/S0959270922000351\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Summary Low-latitude penguins naturally breed in burrows dug in guano. This affords them a buffered environment that remains cool and humid, reducing the risk of hyperthermia while on land. As a conservation strategy, several versions of artificial housing units have been trialled at various breeding sites of African Penguins (Spheniscus demersus) around South Africa, where former guano exploitation forced many penguins to breed in exposed surface nests. While some units yielded a positive effect on breeding success by providing protection against predation, none of them have effectively mitigated the risk of heat stress in penguins or their eggs. Here, we investigated the microclimate of a recent double-layered design of ceramic artificial nests and compared that to natural burrows, exposed surface nests, and commonly used cement pipe nests, in austral summer 2021 on Bird Island, South Africa. We also recorded penguin behaviour during the hottest period at each of these nest types using remote camera traps to determine the onset of heat stress (panting). Double-layered ceramic nests out-performed all other nest types, including natural burrows, by remaining cooler throughout the day, with temperatures never exceeding 36.7°C. By contrast, all other nest types had multiple episodes where temperatures exceeded 40°C. Double-layered ceramic nests also maintained constant levels of high humidity (relative humidity [RH] >70%) throughout our study, whereas low humidity levels were observed in surface nests (RH ≈ 60%) and cement nests (RH <50%) during midday heat. We observed penguins panting at temperatures of 25°C in nest boxes, and at 22°C in exposed surface nests. This suggests that heat stress in African Penguins may occur much sooner than anticipated and that they are particularly vulnerable to hyperthermia as climate change-related global warming progresses. Fortunately, we are encouraged by the capacity of double-layered ceramic nest boxes to buffer environmental extremes and maintain suitable breeding conditions.\",\"PeriodicalId\":9275,\"journal\":{\"name\":\"Bird Conservation International\",\"volume\":\" \",\"pages\":\"\"},\"PeriodicalIF\":1.5000,\"publicationDate\":\"2022-10-03\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"1\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Bird Conservation International\",\"FirstCategoryId\":\"93\",\"ListUrlMain\":\"https://doi.org/10.1017/S0959270922000351\",\"RegionNum\":4,\"RegionCategory\":\"环境科学与生态学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"BIODIVERSITY CONSERVATION\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Bird Conservation International","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.1017/S0959270922000351","RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"BIODIVERSITY CONSERVATION","Score":null,"Total":0}
Nest microclimate and heat stress in African Penguins Spheniscus demersus breeding on Bird Island, South Africa
Summary Low-latitude penguins naturally breed in burrows dug in guano. This affords them a buffered environment that remains cool and humid, reducing the risk of hyperthermia while on land. As a conservation strategy, several versions of artificial housing units have been trialled at various breeding sites of African Penguins (Spheniscus demersus) around South Africa, where former guano exploitation forced many penguins to breed in exposed surface nests. While some units yielded a positive effect on breeding success by providing protection against predation, none of them have effectively mitigated the risk of heat stress in penguins or their eggs. Here, we investigated the microclimate of a recent double-layered design of ceramic artificial nests and compared that to natural burrows, exposed surface nests, and commonly used cement pipe nests, in austral summer 2021 on Bird Island, South Africa. We also recorded penguin behaviour during the hottest period at each of these nest types using remote camera traps to determine the onset of heat stress (panting). Double-layered ceramic nests out-performed all other nest types, including natural burrows, by remaining cooler throughout the day, with temperatures never exceeding 36.7°C. By contrast, all other nest types had multiple episodes where temperatures exceeded 40°C. Double-layered ceramic nests also maintained constant levels of high humidity (relative humidity [RH] >70%) throughout our study, whereas low humidity levels were observed in surface nests (RH ≈ 60%) and cement nests (RH <50%) during midday heat. We observed penguins panting at temperatures of 25°C in nest boxes, and at 22°C in exposed surface nests. This suggests that heat stress in African Penguins may occur much sooner than anticipated and that they are particularly vulnerable to hyperthermia as climate change-related global warming progresses. Fortunately, we are encouraged by the capacity of double-layered ceramic nest boxes to buffer environmental extremes and maintain suitable breeding conditions.
期刊介绍:
Bird Conservation International is a quarterly peer-reviewed journal that seeks to promote worldwide research and action for the conservation of birds and the habitats upon which they depend. The official journal of BirdLife International, it provides stimulating, international and up-to-date coverage of a broad range of conservation topics, using birds to illuminate wider issues of biodiversity, conservation and sustainable resource use. It publishes original papers and reviews, including targeted articles and recommendations by leading experts.