Sickle-billed Vanga on Fony Baobab at golden hour
Sickle-billed Vanga (Falculea palliata) perched on Fony Baobab (Adansonia rubrostipa) during the golden hour in Mangily Spiny forest, Madagascar. The Sickle-billed Vanga is the largest of the Malagasy Vangas. The endemic Vangidae family is a telling example of Darwin's adaptive radiation where evolution has managed to create a woodpecker form a warbler. The Vangidae are the only known birds which experienced two peaks of rapid diversification. It is now 25 million years ago that an originally African ancestor of the Vangidae arrived on Madagascar. Since potential predators and competitors had not reached the island at this time, this allowed the vangas to quickly occupy ecological niches, diversify and spread across the island. This first bout of rapid diversification resulted in vanga species which differ considerably in terms of body size. The second peak of diversification occurred 10 to 5 million years and was caused by an increase in available ecological niche space. Morphological key innovations of a new shape of bill, curved bills, enabled new foraging strategies. These bills such as that of the sickle-billed vanga enabled the new species to retrieve insects hidden under the bark of trees, and so occupy a new dietary niche.