Bautista A, Drummond H, Martínez-Gómez M, Hudson R
Centro de Investigaciones Fisiológicas, Universidad Autónoma de Tlaxcala, Tlaxcala, México.
Dev Psychobiol. 2003 Nov;43(3):208-15. doi: 10.1002/dev.10134.
Newborn rabbits compete vigorously for the mother's milk, and survivors benefit from littermate deaths. Here we report that rabbit pups also may benefit from littermate presence in terms of increased thermal efficiency. Pups nursed normally once a day by their mother but otherwise raised alone had a lower probability of survival, lower body temperature, and lower efficiency of converting milk into body mass than their siblings raised with littermates. The contribution of a more favorable thermal environment to the better growth and survival of group-raised pups was supported by the finding that single pups raised at higher ambient temperatures grew more rapidly than single pups raised at lower temperatures. These effects were most clearly seen across Days 2 to 5, after which time differences between treatment groups were no longer significant. Thus, the results of this study suggest that the benefits as well as costs of having siblings must be weighed against each other when considering the manner in which sibling presence influences individual development and survival.
新生兔子会激烈地争夺母乳，而存活下来的兔子会从同窝幼崽的死亡中受益。在此，我们报告称，兔崽在提高热效率方面也可能受益于同窝幼崽的存在。每天由母亲正常哺乳一次但其他时间单独饲养的幼崽，与和同窝幼崽一起饲养的兄弟姐妹相比，存活概率更低、体温更低，并且将乳汁转化为体重的效率也更低。在较高环境温度下饲养的单只幼崽比在较低温度下饲养的单只幼崽生长得更快，这一发现支持了更有利的热环境对群体饲养幼崽更好的生长和存活的贡献。这些影响在第2至5天最为明显，之后各处理组之间的差异不再显著。因此，本研究结果表明，在考虑同窝幼崽的存在对个体发育和存活的影响方式时，必须权衡有兄弟姐妹的利弊。
