Feelings of love could help to keep them happy and content to face the challenges of child rearing .
爱的感觉会帮助它们保持快乐并愿意去面对养育幼鸟带来的困难。
Both take turns incubating their single egg and defending the nest , and both share duties in rearing the hatchling .
它们轮流孵化唯一的卵,共同保卫它们的巢穴,共同承担抚养孵化小鸟的责任。
Here he began an intensive strategy of egg-collecting , captive rearing in the bronx zoo , and release .
于是他在此开始了一项十分细致的扬子鳄蛋收集行动,然后在布朗克斯动物园人工饲养,再放归大自然。
This involves crop rotation and the rearing of " free-range " livestock which are not force-fed hormones or antibiotics .
这包括到轮作与养育“自由牧场”的牲畜,它们都没有被迫食用激素或抗生素。
Over the course of evolution , it was rare for our maternal ancestors to be full-time mothers , said brizendine , because there was always kin-folk around to help with child rearing .