Interspecific association in ungulates of the Bale Mountains National Park, Ethiopia

Abstract

The aim of the study was to determine the frequencies of interspecific association formation and species preferences among five ungulates [bohor reedbuck (Redunca redunca), common warthog (Phacochoerus africanus), grey duiker (Sylvicapra grimmia), Menelick’s bushbuck (Tragelaphus scriptus meneliki) and mountain nyala (Tragelaphus buxtoni)] in the northern Bale Mountains National Park, Ethiopia. Data were collected in three forest patches and in open grassland using total count technique in 2009 and 2011. The total number of ungulate groups found in interspecific associations was 444, comprising 26.8% of the total 1657 groups recorded. For the five study species, the relative frequency with which a given species occurred in interspecific association deviated significantly from the expected mean relative frequency (i.e., 26.8%). Each study species showed preferences to form interspecific associations with one or two other species. Interspecific association formation increased mean group sizes for bohor reedbuck and mountain nyala. And, most of the species had greater overall mean group sizes in the open habitat compared to forest habitat. In general, the association pattern reported here could be attributed to anti-predator response and/or mutual grazing facilitation, which might be beneficial to one or all of the species involved.