Abundance and diversity of ant taxa in Bahir Dar area, northwestern Ethiopia

Abstract

Species diversity and distribution of ants has not been well investigated in Ethiopia or in Bahir Dar area, Ethiopia. The objective of this study was to identify ant taxa and determine their diversity and distribution in different terrestrial and forest habitats in Bahir Dar area. Ants were collected from the ground weekly from December 2015 to November 2016 with 10 × 13 cm baited cards in 4 traps that were 7 metres apart from each. A total of 60,000 ant specimens consisting of 5 subfamilies: Formicinae, Myrmicinae, Ponerinae, Dorylinae and Dolichoderinae and 7 genera, i.e., Lepisiota, Myrimicaria, Pheidole, Axinidris, Centromyrmex, Camponotus, Dorylus, were recorded. Myrimicinae and Formicinae were more abundant than other subfamilies. Lepisiota, Myrimicaria and Pheidole were the most abundant genera. Shannon’s diversity index was higher for the roadside, built up area (residential and other buildings), grass land, cultivated area and forest in descending order. Evenness was found to be between 0.52 on cement cracks to 0.75 on roadsides and built up areas, indicating medium to high evenness, i.e., there was no taxa that was particularly dominant. Populations were significantly higher during the rainy season (F = 37.9, df = 51,356, p<0.0001). The aggressive Dorylus was absent during the dry season, an indication that wet ground was its preference for foraging. This study was the first of its kind in the area, and can serve as a benchmark for future reference to ant taxa in the area.

Keywords/phrases: Ethiopia, Formicidae, Habitat, Population Dynamics, Season