The first description of the nest and egg of the Long-billed Forest-warbler Artisornis moreaui with additional notes on the breeding of the Red-capped Forest-warbler A. metopias

Abstract

We present the first description of the nest and egg of the Long-billed Forest-warbler Artisornis moreaui recently discovered in Nilo Nature Forest Reserve, Tanzania. Two subspecies are recognised: the nominate one, endemic to East Usambara Mountains in northeastern Tanzania, and sousae, endemic to the Njesi Highlands in northern Mozambique. Both are treated as distinct species by BirdLife International, which has classified the first as Critically Endangered, and the second as Endangered. Before this discovery, breeding information had been limited to observations of fledglings. Because in the East Usambaras A. moreaui shares habitat with its putative sister-species, Red-capped Forest-warbler A. metopias, we also provide additional information on the nesting of this species. Although the nests of the two species can be difficult to differentiate, their eggs are distinct. The markings on the egg of A. metopias are spread over the entire surface, while on the egg of A. moreaui the markings are concentrated at the broad end.