Burrow limitations and group living in the communally rearing rodent, Octodon degus.
Burrow limitations and group living in the communally rearing rodent, Octodon degus.
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DOI：
10.1644/09-mamm-s-383.1
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发表时间：
2011
影响因子：
1.7
通讯作者：
Hayes LD
中科院分区：
文献类型：
--
作者：
Ebensperger LA;Chesh AS;Castro RA;Tolhuysen LO;Quirici V;Burger JR;Sobrero R;Hayes LD
群体生活被认为是进化的时候，个人获得净健身优势，由于减少捕食风险或提高觅食效率，但也当个人被迫留在群体，这往往发生在高密度条件下，由于独立繁殖的关键资源的限制。生态限制对社会性的影响在繁殖在群体成员之间更均匀地分配的物种中研究得很少。先前的研究在caviomorph啮齿类动物degus（一种新世界hystricognath）中发现，没有证据表明群体生活赋予优势，并表明洞穴限制影响社会群体的形成。我们的目的是研究这些啮齿动物的社会性的生态限制的相关性。我们4年的研究表明，没有相关的degu密度和使用洞穴系统。洞穴系统的使用频率与degus是不相关的质量，这些结构，只有在1的4年没有洞穴使用的频率随着食物丰富度的下降而下降。无论是每一组的女性人数，也不总组大小（相关措施的德古社会性）的变化与年度密度的德古。尽管2008年社会群体中的男性人数较低，但这一变化与不同的密度没有明显关系。社会群体中繁殖的女性比例接近99%，并且在不同密度的年份中没有变化。我们的研究结果表明，社会性在degus是不是在繁殖过程中的洞穴限制的后果。栖息地的限制是否有助于脊椎动物社会系统的变化进行了讨论。
Group living is thought to evolve whenever individuals attain a net fitness advantage due to reduced predation risk or enhanced foraging efficiency, but also when individuals are forced to remain in groups, which often occurs during high-density conditions due to limitations of critical resources for independent breeding. The influence of ecological limitations on sociality has been studied little in species in which reproduction is more evenly shared among group members. Previous studies in the caviomorph rodent Octodon degus (a New World hystricognath) revealed no evidence that group living confers an advantage and suggest that burrow limitations influence formation of social groups. Our objective was to examine the relevance of ecological limitations on sociality in these rodents. Our 4-year study revealed no association between degu density and use of burrow systems. The frequency with which burrow systems were used by degus was not related to the quality of these structures; only in 1 of the 4 years did the frequency of burrow use decrease with decreasing abundance of food. Neither the number of females per group nor total group size (related measures of degu sociality) changed with yearly density of degus. Although the number of males within social groups was lower in 2008, this variation was not related clearly to varying density. The percentage of females in social groups that bred was close to 99% and did not change across years of varying density. Our results suggest that sociality in degus is not the consequence of burrow limitations during breeding. Whether habitat limitations contribute to variation in vertebrate social systems is discussed.