Vertebrate surveys in the ancient and endemic-rich Afromontane forests of Tanzania continue to reveal new species and range extensions. Here we report on a survey conducted during October–November 2013 in the Udzungwa Mountains, the southernmost and largest block within the renowned Eastern Arc Mountains. The target forest, Iyondo, is part of the Kilombero Nature Reserve, which was gazetted in 2007 to allocate upgraded protection status to a number of forest reserves to the west and south of the Udzungwa Mountains National Park (Oryx, 41, 429–430). Within this protected area Iyondo is the south-westernmost forest patch, with an extension of 28 km2, comprising mostly pristine montane moist forest at elevations of 1,200–1,900 m. As far as we are aware only one biological survey has been conducted previously in this forest, targeted mainly at primates.
Our survey targeted medium–large mammals and forest birds. For mammals we used camera-trapping and opportunistic observations. We deployed 16 digital camera-traps each for a maximum of 40 days, resulting in a total sampling effort of 635 camera-days. To maximize captures, cameras were set opportunistically along wildlife trails. Forest birds were surveyed using a combination of mist netting and observations. Netting was carried out for 7 days, using 12 12-m-long nets. After identification the birds were released.
Camera-trapping yielded 2,320 photographs or video-clips of 12 species of mammals belonging to 11 genera. The most significant record was of Abbott's duiker Cephalophus spadix, which was captured on three occasions. This is a large, Endangered duiker endemic to Tanzania, restricted to a few montane forests, with Udzungwa being considered the species' stronghold (Oryx, 46, 14–15). In Udzungwa Abbott's duiker occurs in most of the largest forest blocks but is known to be heavily hunted in unprotected sites, and thus this additional record is of considerable conservation relevance. Among the other forest mammals detected was Lowe's servaline genet Genetta servalina lowei, which was captured on camera-traps on 14 separate occasions. This genet subspecies is endemic to moist forests in the Eastern Arc Mountains (Oryx, 40, 468–471). Besides the camera-trapped species we also sighted a galago whose identification requires confirmation but which may be a new record of the mountain galago Galagoides orinus. We also confirmed the presence of the Udzungwa-endemic red colobus monkey Procolobus gordonorum, along with the Angolan colobus Colobus angolensis and Sykes' monkey Cercopithecus mitis monoides/moloneyi.
Sixty species of montane forest birds were recorded, including the Vulnerable Udzungwa-endemic rufous-winged sunbird Nectarinia rufipennis. Other Red-Listed bird species recorded were the white-winged apalis Apalis chariessa, dapple-throat Arcanator orostruthus and Swynnerton's robin Swynnertonia swynnertoni (all Vulnerable) and the Endangered Usambara weaver Ploceus nicolli.
Overall our survey confirmed that Iyondo is a typical Eastern Arc montane forest, with many restricted-range species. Despite being remote and comprising predominantly steep terrain, we found signs of human encroachment in the form of hunting, tree logging and pole cutting. We found several snares and obtained some images of poachers with the camera-traps. The forest surroundings have been cleared for subsistence agriculture by communities living in villages to the north and west of the forest. Despite the forest being fully inside a Nature Reserve, and the communities being aware of its borders and regulations, there is no active protection, mirroring the condition of other forests in the southern and western part of the Udzungwa Mountains. We recommend that appropriate measures are enacted to ensure the protection of this important forest.
