Feeding preferences in 2 disjunct populations of tiger snakes, Notechis scutatus (Elapidae)
Feeding preferences in 2 disjunct populations of tiger snakes, Notechis scutatus (Elapidae)
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DOI：
10.1093/beheco/arl004
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发表时间：
2006-09-01
影响因子：
2.4
通讯作者：
Bradshaw, Don
中科院分区：
文献类型：
--
作者：
Aubret, Fabien;Burghardt, Gordon M.;Bradshaw, Don
遗传和表型水平的变异在对食物和食物相关刺激的反应中起着重要作用。了解这些变化对于了解种群如何适应不断变化的环境至关重要。我们调查了2虎蛇种群的饮食偏好，并比较了饮食幼稚动物（实验室出生的新生儿），饮食控制动物（实验室饲养的青少年），和自然饮食经验丰富的动物（野生捕获的成年人）的反应，从6个猎物类型（小鼠，石龙子，银鸥，鸡，剪水，青蛙）的视觉和化学线索。大陆种群栖息在沼泽中，主要以青蛙为食，并遭受严重的捕食。第二个种群居住在附近一个没有死水的近海小岛上（没有青蛙）;主要以石龙子、老鼠为食，成年后以银鸥幼鸟为食;没有已知的捕食。虽然不同的猎物吃的2个人口，成年野生捕获的蛇从两个人口表现出显着的偏好3种类型的猎物（青蛙，小鼠和小鸡），无论他们的自然饮食。新生儿对所有猎物线索的反应都比对两个种群中的刺激物的反应要大。然而，岛上的新生儿表现出显着更高的兴趣，银鸥小鸡刺激（岛上成年蛇的主要猎物）比他们的大陆同种。实验室饲养的幼鼠在喂食幼鼠7个月后，表现出明显的行为可塑性。我们的结论是，基于遗传的差异，食物相关的线索是很重要的虎蛇，但他们也能够行为可塑性。岛成人和新生儿蛇表现出的猎物类型不再自然消耗（青蛙）的反应，这表明行为特征可能已被保留了很长一段时间，在放松的选择。岛屿新生儿表现出强烈的兴趣，在一个新的猎物项目（银鸥）。这一结果补充了以前的工作，描述了岛蛇如何发展出吞下比平常更大的猎物的能力，以及似乎发展出对它们的品味。
Variations at both the genetic and phenotypic levels play an important role in responses to food and food-related stimuli. Knowledge of such variations is crucial to understanding how populations adapt to changing environments. We investigated the dietary preferences of 2 tiger snake populations and compared the responses of diet-naive animals (laboratory-born neonates), diet-controlled animals (laboratory-reared juveniles), and natural diet-experienced animals (wild-caught adults) to visual and chemical cues from 6 prey types (mouse, skink, silver gull, chicken, shearwater, and frog). The mainland population inhabits a swamp, feeds mostly on frogs, and suffers heavy predation. The second population inhabits a small nearby offshore island with no standing water (no frogs); feeds mostly on skinks, mice, and, as adults, silver gull chicks; and suffers no known predation. Although different prey are eaten in the 2 populations, adult wild-caught snakes from both populations showed a significant preference for 3 types of prey (frog, mouse, and chick), irrespective of their natural diet. Neonates responded to all prey cues more than they did to control stimuli in both populations. However, the island neonates showed significantly higher interest in silver gull chick stimuli (the main prey of the island adult snakes) than did their mainland conspecifics. Laboratory-bred juveniles displayed behavioral plasticity by significantly increasing their response to mice after being fed baby mice for 7 months. We conclude that genetic-based differences in food-related cues are important in tiger snakes but that they are also capable of behavioral plasticity. Island adult and neonate snakes exhibited responses to prey types no longer consumed naturally (frog), suggesting that behavioral characters may have been retained for long periods under relaxed selection. Island neonates showed a strong interest in a novel prey item (silver gull). This result complements previous work describing how island snakes have developed the ability to swallow larger prey than usual, as well as seemingly developing a taste for them.