Arteaga Lourdes, Bautista Amando, Martínez-Gómez Margarita, Nicolás Leticia, Hudson Robyn
Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala-Universidad Nacional Autónoma de México, Tlaxcala 90070, Mexico.
Physiol Behav. 2008 Jun 9;94(3):510-5. doi: 10.1016/j.physbeh.2008.03.005. Epub 2008 Mar 12.
The European rabbit, both in its wild and domesticated forms, has been a pioneer species in the study of mammalian chemical communication, and illustrates well the difficulty of understanding the functional significance of these often complex signals. Here we investigate the performance of one of the rabbit's most conspicuous chemical signaling behaviors, chin marking (chinning), and the hypothesis that this expresses social dominance. In tests of 21 chinchilla-strain sexually mature males we predicted 1) that animals would show marked and stable individual differences in the frequency of chinning, 2) that these differences would correlate with behaviors associated with dominance such as intrasexual mounting, and 3) that individual differences in the frequency of chinning and dominance-related behaviors would correlate with individual differences in a commonly used physiological indicator of dominance, concentration of serum testosterone. Supporting these predictions and consistent with previous reports, animals showed large and stable individual differences in the frequency of chinning which correlated with the behavioral indicators of dominance and less strongly, with serum testosterone. As our animals had been kept in single cages and without direct contact with other males since weaning, these findings raise the question as to how and when during development such differences among individuals arise. We are currently investigating the possible relation between pups' intrauterine position, postnatal competition among littermates for milk and thermally advantageous positions in the litter huddle, and later differences in indicators of dominance such as those reported here.
欧洲野兔，无论是野生还是家养形式，一直是哺乳动物化学通讯研究中的先驱物种，很好地说明了理解这些通常复杂信号的功能意义的困难。在此，我们研究了兔子最显著的化学信号行为之一——颏下标记（蹭下巴），以及该行为表达社会优势地位的假说。在对21只龙猫品系性成熟雄性兔子的测试中，我们预测：1）动物在蹭下巴频率上会表现出明显且稳定的个体差异；2）这些差异会与诸如同性骑跨等与优势地位相关的行为相关联；3）蹭下巴频率和与优势地位相关行为的个体差异会与常用的优势地位生理指标——血清睾酮浓度的个体差异相关。支持这些预测并与之前的报告一致，动物在蹭下巴频率上表现出很大且稳定的个体差异，这些差异与优势地位的行为指标相关，与血清睾酮的相关性较弱。由于我们的动物自断奶后一直饲养在单独的笼子里，没有与其他雄性直接接触，这些发现引发了一个问题，即个体间的这种差异在发育过程中是如何以及何时出现的。我们目前正在研究幼崽在子宫内的位置、出生后同窝幼崽为获取乳汁和在窝中取暖的有利位置而进行的竞争，与后期优势地位指标差异（如本文所报告的那些）之间可能存在的关系。
