Thirty years of amphibian surveys in the Ukagurus Mountains of Tanzania reveal new species, yet others are in decline

ABSTRACT

Records of biodiversity over time are important resources for assessing conservation priorities. However, such baseline data are missing for regions of key biodiversity importance. The Eastern Arc Mountains of Tanzania are known for their species richness and endemism, but not all mountain blocks have received the same attention. The Ukaguru Mountains, for example, have only infrequently been surveyed by herpetologists, with the first known herpetological survey in 1990. Here we compile and quantify all amphibian survey efforts in the Ukaguru Mountains in the past 30 years, publish an updated species list and comment on the health of amphibian populations and their habitat. We report on fourteen described species of amphibians, with potentially three additional species awaiting formal description. Of these seventeen lineages, seven are endemic to the Ukaguru Mountains. Although total species numbers remain low, compared with other Eastern Arc Mountains, surveys frequently recorded new species for the Ukaguru Mountains and for science. Worryingly, however, endemics, such as the monotypic bufonid Churamiti maridadi, have not been recorded in the past fifteen years. Our analyses show the region is becoming warmer and drier and is experiencing an alarming rate of deforestation. We find that over the past 30 years, dense forest cover inside the boundaries of the forest reserves has reduced by 8.4%.

KEYWORDS:

• caecilians
• climate change
• deforestation
• endemism
• frogs
• Mamiwa-Kisara

Acknowledgements

We thank the Tanzania Commission for Science and Technology (COSTECH research permits RCA 2001-272, 2002-319-ER-99-40, 2011-03-ER-2007-153, 2018-76-NA-2007-153, 2019-34-NA-2009-19), the Tanzania Wildlife Research Institute (TAWIRI) and the Wildlife Division and Tanzania Forest Service agency (TFS) for issuing necessary permits. We thank a number of people for assisting in the fieldwork in the Ukaguru Mountains (especially Charles Kilaita and Wilson Meshack) and the Society for Environmental Exploration / Frontier Tanzania for use of data on their collections. We are also grateful to Nike Doggart, David Gower, Kim Howell and Charles Msuya for providing assistance in the field, advice and support. We thank Alan Resetar, Abigail Wolf, Kathleen Kelly, Harold Voris (FMNH), Neftali Camacho and Greg Pauly (LACM), Andreas Schmitz (MNHG) for access to specimens and information held in their respective collections. The 2001 and 2011 fieldwork was funded in part by a Systematics Association Research Fund grant, the Natural History Museum, London, and a NERC studentship to SPL. The 2012 fieldwork was funded by a Fulbright Scholarship to JGL. The 2013 fieldwork by Václav Gvoždík was funded by the Freiwillige Akademische Gesellschaft Basel. The 2019 fieldwork by HCL and colleagues was funded by the Mohamed bin Zayed Species Conservation Fund (Project Number 180518076). Finally, we would like to dedicate this work to Dr Bill Stanley who made a huge impact on our understanding of African biodiversity, as well as with the people he worked with. In particular, Bill’s surveys in the Ukaguru Mountains were pivotal in highlighting the importance of Tanzanian forests with the collection of the remarkable species Churamiti mardidadi. He is sorely missed.