Genetic Diversity and Behavioral Ontogeny

动物如何适应环境的变化？所有健康、外表正常的个体或他们的后代都同样有能力存活下来吗？由于寻找和利用食物资源是生存和占领新的或改变的栖息地的重要方面，本提案旨在研究具有已知的利用新猎物的一般饮食的物种的觅食和食物使用。这一物种是常见的吊袜蛇，Thamnopits sirtalis，可以吃各种小动物。这位研究人员将跟踪婴儿从出生到出生前几个月的情况，研究遗传背景、饮食和个体发育对食物选择、觅食能力和生长的影响。对猎物的最初反应涉及新生的普通吊袜带蛇的化学线索。个体之间有很大的差异，即使是来自同一窝。不同猎物类型的经验可以改变猎物识别、猎物偏好和捕食能力。这个项目将用来自同一自然地区的母亲所生的不同幼崽的蛇来研究这种个性和可塑性。由于蛇的一个优势是每一位母亲生下的动物数量很多，所以每一窝蛇都会被分成不同的组，以控制或自由选择的饲料饲养。这个物种的另一个优势是，一个给定的雌性所生的不同的婴儿可能有不同的父亲。因此，识别一窝蛇中哪些蛇的父亲相同或不同，有助于将遗传因素与产前环境因素区分开来。新开发的微卫星DNA技术将被应用于识别父亲相同或不同的动物。希望这项工作的结果将有助于预测当动物面临不同或变化的环境时，觅食的哪些方面对生存最重要，以及环境和遗传差异如何相互作用。

How do animals adapt to changes in their environments? Are all healthy, normal appearing individuals or their offspring equally able to survive? Since finding and utilizing food resources are important aspects of survival and the occupation of new or altered habitats, this proposal aims at the study of foraging and food use in a species with a generalized diet that is known to exploit novel prey. This species is the common garter snake, Thamnophis sirtalis, which can feed on a variety of small animals. This investigator will follow babies from birth through the first months of life in a study that will look at the effects of genetic background, diet, and ontogeny on food choice, foraging ability, and growth. The initial responses to prey involve chemical cues in newborn common garter snakes. There is great variability among individuals, even from the same litter. Experience with different prey types can alter prey recognition, prey preference, and prey capturing ability. This project will investigate this individuality and plasticity with snakes from different litters born to mothers from the same natural area. Since one advantage of snakes is the large number of animals born to each mother, snakes from each litter will be put in various groups raised on controlled or free-choice diets. Another advantage of this species is that different babies born to a given female may have different fathers. Thus identifying which snakes in a litter have the same or different fathers can help separate genetic factors from prenatal environmental ones. Newly developed microsatellite DNA techniques will be applied in identifying animals with the same or different fathers. It is hoped that the results of this work will help in predicting which aspects of foraging are most important to survival when animals confront different or changed environments, and how environments and genetic differences interact.