1·Some species of Arctic birds are threatened by recent sharp increases in the population of snow geese, which breed in the Arctic and are displacing birds of less vigorous species.
某些种类的北极鸟受到近来雪雁数量急剧增加的威胁，这些雪雁在北极繁殖，并且正在取代生命力较弱的鸟类。
2·Since they can and do successfully inter-breed, they cannot be classed as different species.
既然它们能够而且确实可以成功杂交繁殖，它们就不能被归为不同的物种。
—— 《柯林斯英汉双解大词典》
3·The reserve's mission is to observe, study and breed the endangered species to increase their chances of survival.
保护区的任务是观察，研究和繁殖频域灭绝的物种，增加它们的生存机会。
4·What does it take to encourage endangered species to breed?
用什么措施来鼓励濒危物种的繁殖呢？
5·Researchers only realised that the breed living on the islands of Borneo and Sumatra was a new species - distinct from clouded leopards living elsewhere in Asia - in 2007.
到2007年研究人员才发现生活在婆罗洲和苏门答腊岛的云豹是一个新的物种，与亚洲其他地方的云豹明显不同。
6·She found, as she had hypothesised, that co-operatively breeding birds routinely have stronger immune responses to PHA than closely related species that do not breed co-operatively.
她发现，正如她所设想的一样，有合作哺育行为的鸟类通常会有比无此行为的相近物种的其他鸟类更强的免疫反映。
7·He said that very early springs can prove disastrous for species who breed too early making their offspring susceptible to unexpected cold or wet snaps later in the season.
据英国国民托管组织的自然保育专家马修·奥茨解释说，“春天来得太早对很多物种其实是个灾难，因为它们繁殖的太早，后代就很容易受到突如其来的寒潮或降雨影响。 寒冷的冬天让动物能够正常冬眠，而温暖的春天和早早到来的夏天为昆虫创造了理想的环境来大量繁殖，并进而保证了秋天果园、树林和灌木丛里各种浆果的大丰收。”
8·Almost half of the bird species that breed in Britain leave for the winter, sometimes travelling prodigious distances.
几乎有一半在英国繁殖的鸟类要冬徙，有时飞越的距离相当惊人。
9·Plovers, curlews, and dozens of species of songbirds breed here.
珩科鸟、鹬以及数十种鸣鸟在此繁衍生息。
10·Many of the bird species that breed in the temperate forests, marshes and backyards of North America spend the winter months in the tropics of the Caribbean, and Central and South America.
许多在北美温带的森林、沼泽、草地等地区繁殖的鸟类，在冬季会飞去热带的加勒比海地区或者美国的中部、南部过冬。