The amphibians of Monte Alén National Park

: bioacoustics, ecology and conservation

Abstract

Despite facing growing habitat degradation and loss, large swathes of central Africa have never been surveyed for amphibians, the most threatened Class of vertebrates. Small and highly biodiverse, the continental portion of Equatorial Guinea, Rio Muni, is one such region from which little published research on amphibians exists. Most notable is the absence of ecological studies, threat assessments and an up-to-date species inventory. To address this knowledge gap, amphibian species were surveyed in Monte Alén National Park using both visual and acoustic survey methods. This study aimed to update the regional species inventory and understand the effects of land use on amphibian species. To investigate the effect of conversion to agriculture, the leading cause of forest degradation in Rio Muni, amphibian species richness and composition between aquatic breeding habitats was contrasted in two different land use types, agriculture and primary rainforest. In this survey, 47 species are reported, including first time records for the country (four species), as well as for Rio Muni region and Monte Alén National Park. Visual and acoustic survey methods detected unique species assemblages, demonstrating the value of multi-method surveys when monitoring for amphibians. This study evidences the benefits of passive acoustic monitoring to survey for amphibians, an increasingly popular method which had never previously been used to survey amphibians in Equatorial Guinea. This study also confirms the persistence of the Endangered and regionally endemic Conraua goliath, the largest frog species in the world, and provides recommendations for its conservation. While there was no difference in species richness between agricultural and primary forest habitats, species composition was significantly altered through conversion to agriculture, likely through the loss of microhabitats and increased exposure to environmental extremes. These results indicate the value of conserving primary rainforest and diverse aquatic habitats for the maintenance of regional species diversity in Rio Muni.

Date of Award	5 Dec 2023
Original language	English
Awarding Institution	University of Bristol
Supervisor	Marc W Holderied (Supervisor)