Butterfly diversity and community structure across three vegetation zones in Hamericho Mountain Forest, Central Ethiopia

Abstract

Montane forest ecosystems are critical for biodiversity conservation, yet baseline data on butterfly diversity in many Ethiopian highlands remain lacking. This study provides the first baseline inventory of butterfly diversity in Hamericho Mountain Forest, a threatened ecotourism landscape in central Ethiopia. The objectives were to: (1) provide a baseline inventory of butterfly species, (2) compare butterfly diversity and community composition across three vegetation zones (forest, shrubland, and grassland), and (3) identify local habitat characteristics associated with butterfly diversity patterns. Butterflies were surveyed across three purposively selected vegetation zones: a forest site (lower elevation, 2315–2471 m), a shrubland site (mid elevation, 2651–2804 m), and a grassland site (higher elevation, 2902–2981 m). Standardized Pollard walk transects were used over 28 consecutive days. Species richness was compared using rarefaction. Community composition was analyzed using non-metric multidimensional scaling (NMDS) and analysis of similarity (ANOSIM). Generalized linear models (GLMs) were used to assess associations between habitat characteristics and butterfly metrics. Indicator species analysis identified species associated with specific vegetation zones. A total of 32 butterfly species (2037 individuals) from five families were recorded. The forest site had the highest species richness, followed by shrubland, while the grassland site had the lowest. Each vegetation zone supported a distinct butterfly community (ANOSIM: R = 0.595, p = 0.002). Herb cover showed the strongest negative association with butterfly richness and diversity, while canopy cover was positively associated with Shannon diversity. GLM results showed that neither site nor herb cover was significant due to collinearity. Seven indicator species were identified, with Charaxes brutus and Charaxes kirki as forest specialists, and Colias electo as a shrubland-grassland generalist. This study provides a baseline butterfly inventory for Hamericho Mountain. All three vegetation zones support unique assemblages and should be considered for conservation. Future research should sample at overlapping elevations to separate vegetation from elevation effects, extend sampling across seasons, and directly measure tourism impacts.