Een geval van overkapping van een ei bij Torenvalk Falco tinnunculus

On 9 June 2012, four out of five Kestrel eggs in a nestbox in the eastern Netherlands had hatched;; the fifth egg was capped at the blunt end with the shell of a hatched egg. The unhatched chick was pipping, but the pipping hole was covered by the extra egg shell, effectively preventing the chick from hatching. The egg-­cap was removed and the egg partly opened to facilitate the hatching chick. On 19 June, the nest contained five chicks, the fifth about two days junior from the remaining chicks but in good con-­ dition (196 g, at an age of 16 days old). All chicks eventually fledged.