Common cuckoo, warbler eggshells undergo similar levels of eggshell thinning

[ScienceDaily]

As avian embryos develop, they draw needed calcium from the inner most layer of their eggshell, which in turn thins the eggshell and facilitates hatching. Yet, parasitic cuckoos, which lay their eggs in nests of other bird species (hosts), must maintain thick eggshells to avoid pecking and ejection by the sharp beaks of the foster parents. A new study shows that common cuckoo eggs undergo similar degrees of embryonic eggshell thinning as eggs of their host, thus maintaining thick-shelled eggs at all stages of development.

 

Read the full article on ScienceDaily