Section outline

  • A male peacock displaying its vibrant, colorful tail feathers to attract females.

    Why do peacocks have huge, bright feathers ?
    ::为什么孔雀有巨大而明亮的羽毛?

    Male peacocks use their colorful feathers to attract females. Females tend to mate with the males with the largest, brightest feathers. A large, bright tail indicates the male is healthy and likely to produce healthy offspring . You've probably also heard "sing." Eagles do aerial acrobatics and tumbling. These are other ways to attract mates.
    ::雄性孔雀用它们多彩的羽毛吸引雌性。 雌性往往与最大、最明亮的羽毛雄性交配。 一只大而明亮的尾巴表明雄性是健康的, 并有可能产生健康的后代。 您可能也听到过“ 唱歌 ” 。 雄性鹰会做空中杂技表演和摇晃。 这些是吸引伴侣的其他方法。

    Reproduction in Birds
    ::鸟类生殖

    How do birds reproduce? We know that chickens lay eggs . But how do they do that?
    ::我们知道鸡蛋产卵,但是它们怎么做到的?

    It all starts with behavior aimed at attracting a mate. In birds, this will involve a type of display, usually performed by the male. Some displays are very elaborate and may include dancing, aerial flights, or wing or tail drumming. Most male birds also sing a type of song to attract females. If they are successful at attracting a female, it will lead to breeding.
    ::它始于旨在吸引伴侣的行为。 在鸟类中, 这将涉及一种展示, 通常由男性表演。 有些展示非常精细, 可能包括舞蹈、空中飞行、翼翼或尾鼓。 大多数雄鸟也唱一首歌来吸引雌鸟。 如果它们成功地吸引了雌鸟, 它将导致繁殖。

    Like , birds have a cloaca , which is a single exit and entrance for , eggs, and waste. Birds reproduce by internal fertilization when an egg is fertilized inside the female. Female birds form a yolk inside their bodies which the male can fertilize by passing sperm through the cloaca. With or without internal fertilization, the yolk develops into a hard-shelled egg that the bird lays (usually in a nest). Fertilized eggs develop a thin, fluid-filled membrane called the amnion that forms a closed sac containing the embryo . The embryo of the fertilized egg develops into a baby bird that hatches.
    ::比如,鸟儿有一个木乃伊,这是鸟卵和废物的单一出口和入口。当卵在雌性体内受精时,鸟儿通过体内受精而通过体内受精而繁殖。雌性鸟在体内形成蛋黄,雄性鸟可以通过通过花粉传递精子来施肥。无论有无体内受精,卵子都会发展成鸟(通常在巢中)所产的硬壳蛋。受精卵会形成一种稀薄的、含液体的膜,叫做构成胚胎的闭闭塞的薄膜。受精蛋的胚胎会发展成孵化的幼鸟。

    Protecting Offspring
    ::保护犯罪源头

    Why do you think eggs come in so many different colors? Birds that make nests in the open have camouflaged eggs ( Figure ). This gives the eggs protection against . Some species , like ground-nesting nightjars, have pale eggs, but the birds camouflage the eggs with their feathers.
    ::为什么你认为鸡蛋有这么多不同的颜色?在开放的地方筑巢的鸟有伪装的鸡蛋(图)。这样可以防止鸡蛋的出现。有些物种,如打地喷漆的夜总会,有苍白的鸡蛋,但鸟儿用羽毛遮盖鸡蛋。

    To protect their young, different species of birds make different nests. Birds of all types, from hummingbirds to ostriches, make nests. Many can be elaborate, shaped like cups, domes, plates, mounds, or burrows. However, some birds, like the common guillemot, do not use nests. Instead, they lay their eggs on bare cliffs. Emperor penguins do not have a nest at all; they sit on eggs to keep them warm before they hatch, a process called incubation .
    ::为保护幼鸟,不同种类的鸟类可以建立不同的巢穴。 各种鸟类,从蜂鸟到鸟,都可以建立巢穴。 许多人可以精心设计,形状像杯子、圆顶、板块、丘陵或洞穴。 但是,有些鸟类,像普通的海藻一样,不使用巢穴。 相反,它们把卵产在裸露的悬崖上。 皇帝企鹅根本没有巢;它们坐在卵上,在孵化前保持温暖,这是一种叫孵化的过程。

    How else might a bird help protect its young from predators ? Most species locate their nests in areas that are hidden, in order to avoid predators. Large birds, or those that nest in groups, may build nests in the open, since they are more capable of defending their young.
    ::鸟类还能如何帮助保护其年轻人免受掠食动物的侵袭呢? 多数物种的巢穴都位于隐藏区域,以避免捕食动物。 大鸟类或群筑巢的鸟类可以在露天筑巢,因为他们更有能力保护自己的幼鸟。

    Nest with camouflaged eggs, showcasing speckled patterns among straw for predator protection.
    Nest and eggs of the common moorhen, showing camouflaged eggs.

    Parental Care
    ::父母照料

    In birds, 90% to 95% of species are monogamous , meaning the male and female remain together for breeding for a few years or until one mate dies. Birds of all types, from parrots to eagles and falcons, are monogamous. Usually, the parents take turns incubating the eggs. Birds usually incubate their eggs after the last one has been laid. In polygamous species, where there is more than one mate, one parent does all of the incubating. The wild turkey is an example of a polygamous bird.
    ::在鸟类中,90%至95%的物种是一夫一妻制的,这意味着雄性和雌性会在一起繁殖几年或直到一个伴侣死亡。从鹦鹉到鹰和猎鹰,所有种类的鸟类都是一夫一妻制的。通常,父母轮流孵卵。鸟类通常在上一个鸟类产卵后孵卵。在一夫多妻的物种中,父母一方负责所有孵卵。野生火鸡是一夫一妻制鸟类的一个例子。

    The length and type of parental care varies widely amongst different species of birds. At one extreme, in a group of birds called the magapodes (which are chicken-like birds), parental care ends at hatching. In this case, the newly-hatched chick digs itself out of the nest mound without parental help and can take care of itself right away. These birds are called precocial . Other precocial birds include the domestic chicken and many species of ducks and geese. At the other extreme, many seabirds care for their young for extended periods of time. For example, the chicks of the Great Frigatebird receive intensive parental care for six months, or until they are ready to fly, and then take an additional 14 months of being fed by the parents ( Figure ). These birds are the opposite of precocial birds and are called altricial .
    ::在不同鸟类种类之间,父母照料的长度和类型差别很大,在一种极端情况下,在被称为大象鸟(鸡类鸟)的一群鸟类中,父母照料以孵化为结束,在这种情况下,新戴帽子的小鸡在没有父母帮助的情况下从巢穴里跳出来,可以立即照顾自己。这些鸟类被称为先天鸟类。其他先天鸟类包括家禽和许多种类的鸭子和鹅。在另一种极端情况下,许多海鸟长期照顾自己的幼鸟。例如,大飞禽鸟的小鸡得到六个月的强化父母照料,或直到它们准备好飞翔为止,然后再由父母喂养14个月。这些鸟类与先天鸟类相对,被称为大海鸟。

    In most animals , male parental care is rare. But it is very common in birds. Often both parents share tasks such as defense of territory and nest site, incubation, and the feeding of chicks. Since birds often take great care of their young, some birds have evolved a behavior called brood parasitism . This happens when a bird leaves her eggs in another bird’s nest. The host bird often accepts and raises the parasite bird's eggs.
    ::在大多数动物中,男性父母照料是罕见的。 但在鸟类中,男性父母照料是十分常见的。 父母通常共同承担诸如保护领地和巢穴、孵化和喂养小鸡等任务。 由于鸟类通常非常照顾幼鸟,因此有些鸟类形成了一种叫作双肠寄生虫的行为。 当鸟类将卵留在另一鸟巢中时,就会发生这种情况。 宿主鸟类往往接受并饲养寄生鸟的蛋。

    A parent Great Frigatebird feeding its chick in a nesting area.
    Great Frigatebird adults are known to care for their young for up to 20 months after hatching, the longest in a bird species. Here, a young bird is begging for food.

    Summary
    ::摘要

    • Birds often use flashy displays to attract mates.
      ::鸟类经常用闪闪发光的显示器吸引伴侣。
    • Breeding in birds is through internal fertilization, where the egg is fertilized inside the female.
      ::鸟类的育种是通过体内授精进行的,其中卵在雌性体内受精。
    • Birds generally are monogamous, and both parents help to care for the young.
      ::鸟类一般为一夫一妻制,父母双方都帮助照顾年轻人。

    Explore More
    ::探索更多

    Use the resources below to answer the questions that follow.
    ::利用以下资源回答以下问题。

    Explore More I
    ::探索更多

    • Male Birds Show Off at (3:24)
      ::雄鸟在(3: 24)显示

     

     

    1. Describe two of the displays used by male pheasants to attract females.
      ::描述雄鸡用来吸引雌鸟的两个显示器。
    2. Why might a display be dangerous for the African widowbird?
      ::为什么展示会对非洲的寡妇有危险呢?
    3. Why do you think birds maintain mating displays which are dangerous to them? What benefit do they seem to gain?
      ::你认为鸟儿为什么要保留对鸟儿有危险的交配展呢?它们似乎有什么好处呢?

    Explore More II
    ::探索更多情况二

    • Reproduction in Fish and Birds at (5:07)
      ::鱼类和鸟类繁殖(5:07)

     

     

    1. Do you think that the complexity of birds' mating behavior is reflective of their intelligence? Explain your response.
      ::你认为鸟儿交配行为的复杂性 反映了它们的智力吗?
    2. How long do mated bird pairs stay together?
      ::配对的鸟要在一起多久?
    3. Why is parental care by both parents important for some birds?
      ::为什么父母双方的父母照顾对某些鸟类很重要?

    Review
    ::回顾

    1. What are examples of displays used by birds to attract mates?
      ::鸟类用来吸引伴侣的展品有哪些例子?
    2. Describe parental care of offspring in birds.
      ::描述鸟类后代的父母照料。
    3. Distinguish between altricial and precocial birds.
      ::区分进化鸟类和前科鸟类。
    4. Give three examples of precocial birds.
      ::举三个先天鸟类的例子。
    5. What is brood parasitism?
      ::什么是原生寄生虫炎?