Monday, 3 December 2018

The mammal team wraps up its operations

By Zoe Woodgate

As 2018 draws to a closer to the end, the mammal team wraps up its operations. The last two years have been filled with fieldwork, data processing and analysis. The mammal team, led by Nadine Hassan and Zoe Woodgate, have dedicated months to the project. Medium to large mammals (such as impala) were surveyed at 30 sites, whilst small mammals (like elephant shrew) were surveyed at 25 sites. Sadly, as sampling for small mammals requires live trapping, it is far more dependent on climatic conditions and so we were unable to sample the final five sites. However, the small mammal dataset was bolstered by key museum and institutional databases. 21 400 records were used to investigate historical patterns of small mammal diversity in South Africa.

Zoe Woodgate and Nadine Hassan

41 larger mammal species were recorded across the 30 sites using camera trapping. 270 cameras were operational for a minimum of 30 days across all the sites, producing a dataset of over 70 000 photographic captures. These included the more common karoo species, such as steenbok or meerkat, and some rarities like black-footed cat. We did not get any photographs of the critically endangered riverine rabbit, to the disappointment of Zoe. However the diversity of species captured was astounding, and the many antics caught on camera were a delight to all. There was the notable absence of large carnivores (such as leopards and hyenas) from any of the sites that were visited. Of course this is unsurprising, given that commercial farming dominates the karoo landscape. Preliminary work on the dataset suggests that this land use has little impact on the diversity of mammal species, as species diversity was not affected by live stocking rates. More complex models will tease apart the drivers of diversity in the upcoming months.

Having a quick munch after release
Elephant shrew perched on Nadines leg

Nadine’s work on the small mammal dataset has been encouraging. There have been many new and exciting discoveries A total of 11 rodents, 4 elephant-shrews and 1 shrew species were recorded. However initial DNA work has uncovered cryptic species not thought to occur at the 25 sites. One was the addition of two novel locations for a recently described species- Elephantulus pilicaudus. Nadine is currently investigating whether historical land use in the karoo shaped the present small mammal community. 

All this work would not have been possible without the kindness and generosity of the karoo farmers. Their compassion cannot be understated, and their love for the land was beautiful to behold. We wish to thank them for opening their homes to us and allowing us to work on their property. The BioGaps team have been fantastic as well, and in particular we thank Gigi Laidler and Carol Poole for their hard-work and assistance.

A sneaky aardwolf answering the call of nature


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