Camera trapping observations of the Kloof Frog, Natalobatrachus bonebergi, in South Africa, reveals effects of environmental conditions on breeding behaviour patterns

The threatened Kloof Frog (Natalobatrachus bonebergi) is associated with coastal forested rocky streams in the KwaZulu-Natal and Eastern Cape provinces, South Africa. Their expanded toe tips allow them to navigate rocks, branches and leaves, where the species lays distinct egg clumps that overhang slow-flowing streams, into which hatching tadpoles drop to complete their development. A decade of implementation of a provincial monitoring and surveillance protocol led to the observation that there were regular egg clump laying sites, suggesting that this species was an ideal candidate to examine behaviour in relation to environmental factors using camera traps. The main objective of the study was to determine the efficacy of using camera trap imagery to understand this species’ behaviour to inform conservation management. From January to December 2021, a camera trap was installed at a site where egg clumps are regularly laid in Vernon Crookes Nature Reserve, KwaZulu-Natal, South Africa. Data on breeding and non-breeding behaviour were captured from camera trap images. Data on environmental variables, including temperature, rainfall and lunar albedo, were also collected. Results showed that the temperatures of habitats used by N. bonebergi were significantly cooler than the surrounding areas. Natalobatrachus bonebergi was active throughout the year and bred from September to April. Breeding activity duration decreased as lunar albedo increased while activity duration increased as temperature decreased. This is the first use of camera trapping to observe amphibian behaviour in South Africa and proved valuable for documenting ethological patterns that could be used to predict how changes in habitat and climate could impact the species.