The Risk of Sibling Competition in Nestlings
Many individuals can relate to sibling competition. Sibling competition can result form wanting attention, more privileges, or even for more selfish reasons like wanting your personal needs met before your other siblings. However, sibling competition does not only occur in humans but it also occurs in other animals. For example, young birds have been observed competing with their siblings within their colonies resulting in many nestlings falling out of their nest. This has been observed to happen quite frequently, with over 350 living findings a year. Falling out of the nest is usually fatal for most nestlings. Several experiments are being conducted that analyze these behaviors and to discover what is exactly causing such fatal catastrophes for the little nestlings.
A lack of space within the nest is the primary cause for sibling competition and disappearance between nestlings. In the June 2006 journal of Animal Behaviour, scientist Bize and Roulin researched this behavior in greater detail to see if they can figure out why space causes such a competition between the nestlings. They discovered that the nestlings engage in jostling for position which is directly related to where the parents deliver the food. This act of jostling can cause the nestlings to either fall out of the nest or to be pushed out of the way by an eager sibling. This results in a lack of motivation in some needy nestlings to go after food in order to protect themselves from the plunge from the nest.
Experiments are being conducted around the word to further understand sibling competition in birds. In a journal from Science , a study of brown-headed cowbirds that parasitized sparrow nest was done. Far more males survive the nest competition when both sexes are grouped together in a colony. It is also less common for a parasitized nestling to fall out of the nest because of their tendency to switch nest rather than compete for food.
Overall, the birds are looking for provisions from their parents. Nestlings tend to stay as close as possible to their parents’ in competition for their full attention, so that they will become a priority during feeling. Siblings can get pushed out of the nest very easily in an attempt to make brood size as small as possible.
posted by TNS (5)
posted by PWH @ 12:44 PM
4 comments
4 Comments:
I was very interested in your article because being a child with two other siblings, I am aware of the effects of sibling rivalry first-hand. I am surprised to find out that like humans, animals likewise exhibit behaviors to capture their parents' attention (in an attempt to gain food as in the case of young birds). I would be curious to know whether other kinds of organisms display similar sibling rivalry behaviors, in addition to humans and birds.
Posted by EJM.
Good article. It's not surprising that the siblings would compete for food but it is surprising that far more males survive. I wonder if this somehow changes the birth rate of the species or if this behavior is done to help increase the male survival rate.
Posted by KVC
I think this was a great article to read for anyone, especially if you have any siblings. As fighting with a brother or sister for more attention, the birds fight for their meals which may cause their death. It's funny how the "shy" bird in this case might go hungry just so he can avoid being pushed out of the nest. Also I am not surprised that more males survive than females. I liked this post, good job!
Posted by ALC
Thank you for all of you comments. I have yet to find any additional data or experiments showing similar sibling rivalry in other animals, however it is sparked my interest. Moreover, I know that several different types of birds have been known to exhibit behaviors of sibling rivalry. Drastic changes in the birth rate of the birds have not been observed and do not resulted from more females falling out of the nest. The pushing that occurs by the young nestlings are not targeted to females but are targeted to all of the nestlings “in the way”. Men just tend to survive more falls from the nest than females do.
TNS comment (5)
Post a Comment
<< Home