Oct 31, 2013

Invasion!

A Bar-throated apalis in the Taita hills (February 2013). Notice the differences between this species and the Taita apalis


If things were not bad enough for our little friend, the Taita apalis, our recent observations show that the situation is getting even worse.

The Taita apalis is one of the world's rarest birds. It only lives in seven small bits of forest, in the Taita Hills of Southern Kenya. Deforestation in the Taita hills has been savage, and currently no more than 500 ha of forest remain - an area more of less of the same size of Central Park in New York!

Our work already showed that there are probably less than 500 individuals of Taita apalis surviving. But the really bad news is that their range is being invaded by another species, the Bar-throated apalis. The Bar-throated apalis had never been observed in the Taita hills in the past, but in the last year, we have spotted individuals of this species with increasing frequency.

Bar-throated and Taita apalis are closely related, and hybridization between the two is likely to occur. If that will happen, the genetic integrity of Taita apalis might be lost, and the species might rapidly disappear.

We don't know the origin of the Bar-throated apalis invaders that we have observed repeatedly at several locations from the end of 2012 up to now. These birds might come from the West Usambara mountains (120km South of the Taita hills) or from the Chyulu hills (70 km West of the Taita).

We are monitoring the situation closely. Urgent issues to understand is how many pairs of Bar-throated apalis have invaded the Taita hills (so far we observed three, but there might be more), where do they originate, and most of all, if they are able to breed and hybridize with the Taita endemic species.

A male Taita apalis, notice the black throat and no bar on the breast