The small mammal community of Mukogodo Forest, Kenya

Urbanization influences small mammal composition, but not species richness in forest fragments in Accra, Ghana

The Accra Plain of Ghana is experiencing rapid urbanization, but there is scant information on its impact on local biodiversity. We assessed the changes in land use/land cover of the Accra Plain since 1991 and evaluated how the observed changes have influenced local small mammals in forest fragments. We applied supervised classification and intensity analysis time-series Landsat imagery data to assess land use/land cover changes between 1991 and 2017. Small mammals were surveyed in two forest fragments, the Pinkwae and Adumanya forests from June 2019 to January 2020, using capture-mark-recapture technique. We compared our data with baseline data gathered in 1991-1992, when large areas of the city remained mostly undeveloped. Our data revealed that the urban area has increased by 832%, while the forest area declined by 85% between 1991 and 2017. The Pinkwae and Adumanya forests, which covered 120 and 1.5 ha, respectively, in 1991 have each been reduced to < 1 ha. We found changes in the small mammal species composition in the forest fragments, but not species richness due to species turnover. Grammomys poensis and Dephomys defua are first records for the Accra Plain. Our data suggested that small forest fragments within the urbanizing landscape are important for maintaining the local small mammal species. For the conservation of local small mammals in urbanizing landscapes, it is important to maintain the greatest possible number of small forest fragments and establish policies that prevent forest remnants from being further depleted.

Composition and diversity of bat assemblages at Arabuko-Sokoke Forest and the adjacent farmlands, Kenya

Recognized as a global biodiversity hotspot, coastal forests in eastern Africa are currently reduced to fragments amidst human modified habitats. Managing for biodiversity depends on our understanding of how many and which species can persist in these modified areas. Aiming at clarifying how habitat structure changes affect bat assemblage composition and richness, we used ground-level mist nets at Arabuko-Sokoke Forest (ASF) and adjacent farmlands. Habitat structure was assessed using the point-centered quarter (PCQ) method at 210 points per habitat. We captured a total of 24 bat species (ASF: 19, farmlands: 23) and 5217 individuals (ASF: 19.1%, farmlands: 82.9%). Bat diversity was higher at ASF (H′, ASF: 1.48 ± 0.2, farm: 1.33 ± 0.1), but bat richness and abundance were higher in farmlands [Chao1, ASF: 19 (19–25), farmlands: 24 (24–32) species (95% confidence interval [CI])]. Understory vegetation and canopy cover were highest at ASF and the lower bat richness and abundance observed may be the result of the under-sampling of many clutter tolerant and high flying species. Future surveys should combine different methods of capture and acoustic surveys to comprehensively sample bats at ASF. Nonetheless, the rich bat assemblages observed in farmlands around ASF should be valued and landowners encouraged to maintain orchards on their farms.