Comparative niche modeling of two bush-shrikes (Laniarius) and the conservation of mid-elevation Afromontane forests of the Albertine Rift

Avian endemism in the Albertine Rift is among the highest of any region in Africa. Conservation of these forests is a high priority, but informed prioritization has been hampered by limited data for most endemic bird species. We employed ecological niche models, coupled with remote sensing and field data, to present a case study of 2 Albertine Rift bush-shrikes (Laniarius) that until recently had been considered conspecific. The ecological niche models are based on presence-only data from museum specimens and sight records from field surveys from the region. We generated a set of competing models with different subsets of environmental variables. We evaluated competing models with an intuitive and broadly applicable model-selection strategy appropriate for assessing suitable habitat for species of conservation concern. Based on its distribution, habitat requirements, and the boundaries of national parks in the Albertine Rift, our results demonstrate that the recently described and cryptic Willard's Sooty Boubou (Laniarius willardi) has lost most of its available habitat within its realized environmental niche and is highly endangered. The Mountain Sooty Boubou (L. poensis) occurs in areas above 2,000 m, where forests are more intact and better protected than mid-elevation forests where L. willardi occurs. These results highlight the plight not only of a recently described species, but also of additional biodiversity confined to mid-elevation forests in the Albertine Rift region.