Development of Parent-Offspring Interactions

[306988 .克拉克]在许多种类的鸟类和一些哺乳动物中，父母抚养的孩子在年龄、体型和性别上都不同。在提供食物时，父母面临着如何将食物分配给这些年轻人的问题。许多雏鸟必须用乞讨的行为来表示它们的饥饿。许多非常普遍的理论预测了父母应该如何分配照顾，以及后代应该付出多少努力来获得照顾。然而，很少有研究确切地表明，父母如何区分个别年轻人以提供他们的特殊需求，而且，年幼或较小的兄弟姐妹如何成功地竞争照顾。本研究将通过实地实验和对红翼黑鹂的观察来解决这些问题，红翼黑鹂不仅在巢内存在年龄差异，而且在生长速度上也存在性别差异。由于年龄和性别，兄弟姐妹之间的行为差异将在运动和视觉能力的对照测试中记录下来，这些测试将使他们能够有效地向父母乞讨。这些测试将使克拉克博士能够确定哥哥妹妹之间竞争能力差异最大的关键时期。实地试验将用于测试父母识别和给予不同发育阶段的孩子适当照顾的能力。发育测试和实验都将用于评估年幼的兄弟姐妹是否能加速某些能力的发展，比如视力，这种灵活性可能有助于他们与年长的兄弟姐妹竞争。这项研究将有助于我们在几个方面理解亲子互动。这将是第一次精确地研究一只无助的雏鸟的大小、年龄和性别如何影响它与父母的互动。这将有助于为脊椎动物亲代和子代行为的理论解释提供必要的经验基础。其次，这项研究可以扩展我们的动物模型用于家庭层面的相互作用，这是目前人类心理学的研究热点。这一领域的核心问题是，兄弟姐妹的存在和身份如何改变家庭环境，以及父母与每个正在发育的子女之间的相互作用。晚熟鸟类的孵化，不像晚熟哺乳动物的同龄幼崽，可以很好地类比年龄错开的人类家庭，尽管时间尺度要短得多。最后，视觉发育的研究利用了一种不同寻常的相机技术，用于研究人类婴儿的近视。作为对雀形目（栖息）鸟类视觉调节的首次研究，雏鸟的数据将有助于我们对包括人类在内的脊椎动物视觉调节的发展及其功能的理解。

9306988 Clark In many species of birds and some mammals, parents raise families of young that differ in age, size and sex. When providing food, parents face the problem of how to distribute it among these young. The young of many birds must signal their hunger by begging behavior. A number of very general theories predict how parents should allocate care and how much effort offspring should make to get it. However, there are few studies of exactly how parents might discriminate between individual young to provide for their particular needs and, further, how younger or smaller siblings compete successfully for care. This study will address these questions with field experiments and observations of red-winged blackbirds, a species that has not only age differences within broods but also sex differences in growth rate. The behavioral differences among siblings due to age and sex will be documented in controlled tests of those motor and visual abilities that would allow them to beg effectively from their parents. These tests will allow Dr. Clark to identify critical periods when the differences in competitive abilities between older and younger siblings are greatest. Field experiments will be used to test parents' ability to recognize and give appropriate care to young of different developmental stages. Both developmental testing and experiments will be used to assess whether or not younger siblings can accelerate the development of some abilities such as vision, a flexibility that might help them compete with their older siblings. This study will contribute to our understanding of parent-offspring interactions in several ways. It will be the first to investigate exactly how a helpless nestling bird's size, age, and sex compared to its siblings affect its interactions with its parents. It will thus help to provide a needed empirical base for theoretical explanations of parent and offspring behavior in vertebrates. Secondly, this study may extend our animal mo dels for family-level interactions, a current research focus in human psychology. The central question addressed in this area is how the presence and identity of siblings alters the family environment and changes the interactions between a parent and each developing offspring. Altricial bird broods, unlike same-age litters of altricial mammals, make excellent analogs of the age-staggered human family, albeit on a much shorter time scale. Finally, the study of visual development utilizes an unusual camera technique used for studying myopia in human infants. As a first study of visual accommodation in passerine (perching) birds, the data on nestling blackbirds will add to our understanding of the development of visual accommodation and its function in vertebrates, including humans.