Common cuckoo lay eggs that better imitate the host's eggs, the host species adapts and is more able to distinguish the cuckoo egg. A study of 248 common cuckoo and host eggs demonstrated that female cuckoos that parasitised common redstart nests laid eggs that matched better than those that targeted dunnocks. Spectroscopy was used to model how the host species saw the cuckoo eggs. Cuckoos that target dunnock nests lay white, brown-speckled eggs, in contrast to the dunnock's own blue eggs. The theory suggests that common redstarts have been parasitised by common cuckoos for longer, and so have evolved to be better
Salim Ali Bird Sanctuary have been recorded and the common species include the striated heron and western reef heron. Other species that have been recorded include the little bittern, black bittern, red knot, jack snipe and pied avocet (on transient sandbanks). The sanctuary is also host to mudskippers, fiddler crabs and other mangrove habitat specialists. A species of crustacean "Teleotanais indianis" was described based on specimens obtained in the sanctuary. Salim Ali Bird Sanctuary Salim Ali Bird Sanctuary is an estuarine mangrove habitat, which is declared as the bird sanctuary, and located on western tip of the Island of Chorão along the Mandovi River,