期刊
HORMONES AND BEHAVIOR
卷 48, 期 3, 页码 329-341出版社
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/j.yhbeh.2005.04.006
关键词
female aggression; challenge hypothesis; steroid hormones; testosterone; estradiol; corticosterone; progesterone; marine iguana; reptile; lizard
We studied steroid hormone patterns and aggression during breeding in female Galapagos marine iguanas (Amblyrhynchus cristatus). Females display vigorously towards courting males after copulating (female-male aggression), as well as fight for and defend nest sites against other females (female-female aggression). To understand the neuroendocrine basis of this aggressive behavior, we examined changes in testosterone (T), estradiol (E-2), corticosterone (CORT), and progesterone (P-4) during the mating and nesting periods, and then measured levels in nesting females captured during aggressive interactions. Testosterone reached maximal levels during the mating stage when female-male aggression was most common, and increased slightly, but significantly, during the nesting stage when female-female aggression was most common. However, fighting females had significantly lower T, but higher E-2 and P-4, than non-fighting females. It remains unclear whether these changes in hormone levels during aggressive interactions are a cause or a consequence of a change in behavior. Our results support the challenge hypothesis, but suggest that E-2 and/or P-4 may increase in response to aggressive challenges in females just as T does in males. Females may be rapidly aromatizing T to elevate circulating levels of E-2 during aggressive interactions. This hypothesis could explain why non-fighting females had slightly elevated baseline T, but extremely low E-2, during stages when aggressive interactions were most common. Although P-4 increased rapidly during aggressive encounters, it is unclear whether it acts directly to affect behavior, or indirectly via conversion to E-2. The rapid production and conversion of E-2 and P-4 may be an important mechanism underlying female aggression in vertebrates. (c) 2005 Elsevier Inc. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据