Birds reproduce sexually by mating and then depositing shelled eggs, which they incubate, hatch and rear. Birds produce sperm and egg cells just as mammals do, but most male birds lack a copulatory organ. Instead, birds mate through a process known as a “cloacal kiss.”
At the end of a bird’s reproductive, urinary and digestive systems lies a hollow chamber called a cloaca. This is true for both males and females. Near the time of mating, the males and females produce sperm and egg cells, respectively. These sexual cells make their way to the cloaca where they reside until mating. Mating is typically a quick phenomenon in which the male mounts the female and briefly presses her cloaca against his. This allow the sperm to transfer to the female’s cloaca.
Weeks later, the shelled eggs will be laid by the female. The female will usually incubate the eggs for a short time, although she may alternate with the male in some species. As the eggs hatch, the mother, father or both will care for them until they are mature enough to take care of themselves. Some birds mature quickly and are called precocial, whereas other take a long time to mature and are called altricial.