Niche partitioning and environmental factors affecting abundance of strepsirrhines in Angola.

The African nocturnal primates (galagos, pottos, and angwantibos: suborder Strepsirrhini) are the result of the first major primate radiation event in Africa, and are found in different primate communities spread across the entire sub-Saharan Africa. Thus, they represent an interesting group of taxa to investigate community strategies to avoid interspecific competition. Here, we present the result of the first study on nocturnal primate communities in western Angola. We aimed to identify habitat factors influencing strepsirrhine abundance, collect evidence of spatial niche segregation, and discuss possible indications of competitive exclusion in this region. We conducted nocturnal surveys at four study sites: Kumbira, Bimbe, Northern Scarp, and Calandula. At each encounter we recorded species, group size, height of animals above ground, and GPS location. We sampled vegetation using the point-centered quarter method and collected data on canopy cover, disturbance, and undergrowth density. We observed a total of five strepsirrhine species with varying community structures. We did not encounter Galagoides thomasi but we recorded a new species Galagoides sp. nov. 4. Levels of disturbance, canopy cover and undergrowth density were the habitat factors that most influenced variation in abundance of Galagoides demidovii and Perodicticus edwardsi, the latter also preferring the habitat with higher tree density. Vertical separation between sympatric strepsirrhines was strongest in Northern Scarp, where overall relative abundance was also highest. Competitive exclusion between G. thomasi and G. sp. nov. 4 may explain why the former was not present within the Angolan Escarpment sites. We observed coexistence between mainly allopatric Otolemur crassicaudatus and P. edwardsi in Kumbira, and of Galago moholi and G. demidovii in Calandula. Both unusual combinations showed some levels of spatial segregation. Habitat characteristics of the Escarpment region are likely to allow for unique nocturnal primate species assemblages. We urge immediate conservation interventions in the Angolan Escarpment.

A brief botanical survey into Kumbira forest, an isolated patch of Guineo-Congolian biome.

Kumbira forest is a discrete patch of moist forest of Guineo-Congolian biome in Western Angola central scarp and runs through Cuanza Norte and Cuanza Sul province. The project aimed to document the floristic diversity of the Angolan escarpment, a combination of general walk-over survey, plant specimen collection and sight observation was used to aid the characterization of the vegetation. Over 100 plant specimens in flower or fruit were collected within four identified vegetation types. The list of species includes two new records of Guineo-Congolian species in Angola, one new record for the country and one potential new species.