Responses of three sympatric snake species to tropical seasonality in northern Australia
Responses of three sympatric snake species to tropical seasonality in northern Australia
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DOI：
10.1017/s0266467402002365
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发表时间：
2002-07-01
影响因子：
1.4
通讯作者：
Madsen, T
中科院分区：
文献类型：
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作者：
Brown, GP;Shine, R;Madsen, T
在澳大利亚干湿相间的热带地区，全年气温都很高，但降雨集中在4个月的雨季。在Fogg Dam自然保护区进行的定期夜间调查提供了三种蛇类生物学属性随时间（每月、季节）变化的数据：水蟒（Liasis fuscus，Pythonidae）、龙骨蛇（Tropidonophis mairii，Colubridae）和板灰色蛇（Stegonotus cucullatus，Colubridae）。所有三个类群的成年人更频繁地遇到在旱季比雨季，而青少年更常见于雨季。成年蛇的性别比例也会随季节变化，但不同物种的变化方式不同。这些性别比例的变化可能反映了生殖活动（交配搜索的男性，产卵迁移的女性），并伴随着增加的遭遇率。在蛙类最多的雨季，海鳗（一种蛙类专家）的摄食率和身体状况最高。在雨季，老鼠会从福格大坝迁移，大多数蟒蛇（老鼠专家）离开这个地区去追踪它们的猎物。留在福格大坝的蟒蛇表现出低进食率和身体状况差。灰岩蛇（一种多面手捕食者）的摄食率或身体状况的季节性变化较小。我们的数据表明，热带季节性引起强烈的波动，在许多属性的蛇种群，和物种之间和物种内的反应模式不同。
In the Australian wet-dry tropics, temperatures are high year-round but rainfall is concentrated in a 4-mo wet season. Regular nightly surveys in the Fogg Dam Nature Reserve provided data on temporal (monthly, seasonal) variation in biological attributes of three snake species: water pythons (Liasis fuscus, Pythonidae), keelbacks (Tropidonophis mairii, Colubridae) and slatey-grey snakes (Stegonotus cucullatus, Colubridae). Adults of all three taxa were encountered more frequently during the dry season than the wet season, whereas juveniles were more commonly encountered in the wet season. The sex ratio among adult snakes also shifted seasonally, but in different ways in different species. These sex-ratio shifts probably reflect reproductive activity (mate-searching by males, oviposition migrations by females) and were accompanied by increased encounter rates. Feeding rates and body condition of keelbacks (a frog specialist) were highest during the wet season when frogs were most abundant. Rats migrated away from Fogg Dam during the wet season, and most pythons (rat specialists) left this area to follow their prey. The pythons that remained at Fogg Dam exhibited low feeding rates and poor body condition. Slatey-grey snakes (a generalist predator) showed less seasonal variation in feeding rates or body condition. Our data show that tropical seasonality induces strong fluctuations in many attributes of snake populations, and that patterns of response differ both among and within species.