Editing Stabilizing selection (section)

=== Birds ===

* Clutch Size − The number of eggs laid by a female bird (clutch size) is typically under stabilizing selection. This is because the female must lay as many eggs as possible to maximize the number of offspring. However, they can only lay as many eggs as they can support with their own resources. Laying too many eggs could expend all of the energy of the mother bird causing her to die and the death of the chicks. Additionally, once the eggs hatch the mother must be able to obtain enough resources to keep all of the chicks alive. Therefore, the mother typically lays a moderate amount of eggs in order to increase offspring survival and maximize the number of offspring.<ref>{{Cite web|url=https://web.stanford.edu/group/stanfordbirds/text/essays/Variation_in_Clutch.html|title=Variation in Clutch Sizes|website=web.stanford.edu|access-date=13 May 2018}}</ref>