Diversity and Abundance Patterns of Amphibians in Rehabilitated Quarries of Bamburi Near Mombasa (Kenya)

Abstract

Amphibians are sensitive to changes in the environment and are, therefore, excellent indicators of success in restoring degraded habitats. As such, a clear understanding on how amphibian populations respond to changes in the environment is required. In order for conservationists to establish if the declining trends are changing, biodiversity recovery studies are essential especially in reclaimed habitats. This study focused on the recovery of amphibians, particularly on frogs, in reclaimed quarries of the Bamburi Cement Plant near Mombasa whereby the diversity, species abundances and composition at different stages of quarry re-establishment were assessed. The study area was divided into three zones based on the 13-year interval since the beginning of the rehabilitation process. Transect surveys and time-constrained search and size method were used for sampling 20 randomly selected sites. Sampling was done during the rainy and the dry seasons, with searches conducted between 900 and 1,600 hours during the day and between 1,800 to 2,100 hours at night. Recording of basic morphological data of collected specimens was done in the field to aid in grouping specimens before voucher materials were preserved in 10% formalin and stored in 70% alcohol. Further identifications and confirmations matching specimens to species were carried out using specialized classification keys from the National Museum of Kenya. Twelve species were encountered across the three zones, with Ptychadena anchietae and Phrynobatrachus acridoides, respectively, the most abundant. It was also noted that amphibian diversity across the quarries was independent of the age of ecological reestablishment (r = -0.5). This is indicated by the higher amphibian diversity in the south and north quarries (N = 1050 and 506 respectively) despite their relatively younger age since reestablishment compared to the central quarry (N = 438). Lower diversity in the central quarry, although the oldest, may be largely attributed to human disturbance. Additionally, exotic plantations across the study area are poor in species since they are monocultures and, thus, not heterogeneous enough to support higher anuran diversity. Since amphibians act as one of the best measure of environmental health, rehabilitation process in the quarries need to embrace mechanisms that support maximum biodiversity recovery such as replanting of more indigenous tree species as opposed to only exotic monocultures.

Breeding Ecology and Population Status of Kenyan Amphibians

“…From the assessment done, there was strong association of two species Phrynobatrachus acridoides (46%) and P. anchietae (44%) with rehabilitated mines in Bamburi mines near Mombasa as shown by their dominance. Although the alpha diversities were higher among these species in central areas of Mombasa, the species abundances were relatively low (compared to SHNR and Taita Hills) and distribution was uneven due to fluctuations in resource, quality of breeding sites, among other factors [18] as shown in Table 3.…”

“…In comparison to these two amphibian rich ecosystems, the survey done in coastal ecosystem that represent a secondary growth after rehabilitation shows low diversity and species richness. In survey conducted in 2013 in rehabilitated mines in Bamburi, central areas of the coast, 12 species were found [18] distributed across nine genera (N = 1994). From the assessment done, there was strong association of two species Phrynobatrachus acridoides (46%) and P. anchietae (44%) with rehabilitated mines in Bamburi mines near Mombasa as shown by their dominance.…”

Anthropogenic effects of habitat modification on anuran species diversity in a swamp forest area, Kenya

“…Appropriate anuran species conservation and management measures in protected and non‐protected areas rely on the knowledge of their biodiversity and habitat preferences (Boyd et al., 2008; Nneji et al., 2021; Rahman et al., 2020), therefore, understanding the consequences of habitat change for biodiversity is critical. Currently, protected area network is insufficient to safeguard the majority of species in the World (Stuart et al., 2004), and their persistence depends upon the effectiveness of conservation action plans (Daily, 2001; Onga'oa et al., 2013; Vandermeer & Perfecto, 2007). To date, there is a little information on the diversity and distribution patterns comparison of anuran species in some protected and non‐protected areas of Kenya.…”

Herpetofauna of the opencast mines in Lower Silesia (Poland)

“…Bąbelewska et al 2014), long-term research of amphibian and reptile colonisation in abandoned opencast mines (e.g. Galán 1997, Ong'oa et al 2013 as well as in the study of bioindication (e.g. Zhelev et al 2014).…”