In this article I have learned about brooding parasites, birds that lay their eggs in other birds nest to be raise. Robert B. Payne wrote this article and discussed many different factors related to the brooding animals and the host nest mothers. This activity of foster mothers raises others babies is interesting and sad at the same tome because the growth of specific species of birds is dying off because of this situation.
The author of this article asked "why do birds rear young that are not their own?" And before this question could be answered he had to give some background on the birds. The most common brooding birds are many different species of cuckoos and cowbirds. These where the most discussed in the article. The bird pick their host mothers in two ways, either they are very careful and try to pick a bird that has eggs kind of like theirs or they over power the nest and lay them any where they please.
An interesting fact about the host mother is if the nest is empty and she comes home and finds an egg, before she lays her own eggs, she will leave the nest and build another one or even build over top the existing egg and not take care of the new baby. This leads to the answer of the question why does the host mother take care of foreign eggs. This answer came to be very simple. The host mothers have not evolved to get ride of the foreign eggs, unlike the brooding bird. Some of the brooding birds have evolved special parts on their feet and tails to remove the host eggs from the nest if her egg will not fit. There for killing the host mother eggs. The host mother have not developed this attachment, so they have to be more careful with the eggs because she could lose her own eggs in the process. The author answers this question by discussing these kinds of factors, because the host mother is worried about the safety of her own off spring it is very rare that she will not raise the foreign baby.
The growth of the host species is already dying off and the only way
to try and prolong the life of these animal the host mother has to make
accommodations for the foreign eggs. And when she does this the species
can survive for one more generation. All of these reason answer the question
of why they raise babies that are not there own, and in reality it is important
for their survival to simply deal with the new comers.
Payne, Robert B. Brooding Parasitism in Birds: Strangers in hte Nest. Bio Sciences. American Institute of Biological Science. Vol.48 No. 5. May 1998. Pgs. 377-385