Lolldaiga Hills Mammal Survey, 2014 Anne-‐Marie C. Hodge
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Lolldaiga Hills Mammal Survey, 2014 Anne-Marie C. Hodge INTRODUCTION Here I describe the results of a combined live trapping and game camera monitoring survey for wild mammals, conducted within the Lolldaiga Hills Conservation Landscape (LHCL) from 22-28 February 2014. The rich and diverse habitats located within the LHCL facilitate the presence of a diverse assemblage of mammalian species, and the primary aim of this survey was to confirm the presence of as many of these species as possible, as well so to gain insights into which habitats within the LHCL are frequented by specific species of interest. Although capture rates were too low to provide accurate abundance estimates, the results of this study yield valuable insights into the presence and site occupancy of some rare and important species with the LHCL, and will help to guide repeated and/or expanded surveys in the future. METHODS Live trapping Survey grids were established at two different sites on Lolldaiga Hills Conservation Landscape (LHCL). The first trap grid consisted of a 400 x 300 grid of live traps positioned along the riverbank near the entrance gate of the property (N 00° 07.384’ E 37° 08.189’). The second trap grid covered 200 x 300 m from the base of a large kopje, through a meadow and across a series of small dam ponds (N 00° 10.022’ E 37° 06.693’). Each grid consisted of five transect lines, each of which contained four Tomahawk live-traps (12 x 10 x 36 in), spaced 100 m apart. At the river site, transect lines were spaced 100 m from each other, while at the dam grid the transect lines were spaced 50 m apart, in order to maximize trap intensity around the water sources. Sherman live traps (3 x 3.5 x 9 in) were positioned every 33 m along each transect with and between the Tomahawk traps, for a total of 20 Tomahawk and 50 Sherman traps on each grid. Each grid was baited for five 2 consecutive nights, resulting in 100 Tomahawk trap nights and 250 Sherman trap nights for each grid. Tomahawk traps were baited each afternoon with boiled eggs and raw beef fat. Sherman traps were baited each afternoon with a mixture of peanut butter and oats. Traps were checked each morning at dawn, and were left closed during the day to avoid heat mortalities. Small mammals captured in Sherman traps were weighed, and their hind foot lengths, sex, age (adult or juvenile), and reproductive status were recorded. Mesocarnivores captured in Tomahawk traps were given metal ear tags with identification numbers if they did not have individualized markings (spots or stripes). On the last two days of the trapping for each grid, mesocarnivores were given semi-permanent markings to avoid undue stress and damage to the animals caused by applying metal ear tags. Camera survey Camera surveys were also conducted at each live trapping site. Reconyx RM45 cameras were deployed across each grid. The cameras were set to “rapidfire” mode, taking one picture per second. Each stimulus of the camera’s sensors resulted in a series of five photographs, repeated until the animal left the view of the camera (ie, until it stopped stimulating the camera sensors). On the river grid, 14 cameras were positioned at a combined Tomahawk/Sherman trap site. On the dam grid, eight cameras were deployed. Fewer cameras were necessary on this grid due to the higher visibility in the more open habitat. Some cameras at the dam grid were positioned on these paired trap sites, while others were deployed strategically to capture images of the banks of the dam ponds. RESULTS Live trapping A variety of both mesocarnivores and small mammals were captured and identified on each grid. On the river grid (Table 1), eight species representing five families were captured. This included three carnivores: two from Herpestidae (Helogale parvula and Herpestes sanguinea) and one from Viverridae (Genetta 3 maculata). The other five species were all rodents, representing the Muridae (Aethomys hindei, Grammomys sp., and Mus sp.), Gliridae (Grammomys sp.), and Sciuridae (Euxerus erythropus). Table 1: Results of a live trapping survey conducted at a river site within the Lolldaiga Hills Conservation Landscape, 22-27 February 2014. Species Common Name Family Captures Individuals Aethomys hindei Bush rat Muridae 11 8 Euxerus erythropus Striped ground squirrel Sciuridae 1 1 Genetta maculata Blotched genet Viverridae 1 1 Narrow-footed woodland Grammomys sp mouse Muridae 4 3 Graphiurus sp African dormouse Gliridae 1 1 Helogale parvula Dwarf mongoose Herpestidae 3 3 Herpestes sanguinea Slender mongoose Herpestidae 2 2 Mus sp. Pygmy mouse Muridae 1 1 On the dam grid, eight species were captured, representing six families. Two of these were carnivores (Genetta maculata and Ictonyx striatus), of the Viverridae and Mustelidae, respectively. Three rodents from the Muridae were captured (Aethomys hindei, Lemniscomys sp., and Lophiomys imhausi), in addition to one rodent from the Gliridae (Graphiurus sp.) and one shrew from the Soricidae (Crocidura sp.). The capture of L. imhausi was especially noteworthy, as this is an elusive and little-known species. Table 2: Results of a live trapping survey conducted at a dam site within the Lolldaiga Hills Conservation Landscape, 23-28 February 2014. Species Common Name Family Captures Individuals Aethomys hindei Bush rat Muridae 3 3 Crocidura sp. White-toothed shrew Soricidae 1 1 Genetta maculata Blotched genet Viverridae 1 1 Graphiurus sp African dormouse Gliridae 1 1 Ichneumia albicauda White-tailed mongoose Herpestidae 1 1 Ictonyx striatus Zorilla Mustelidae 4 3 Lemniscomys sp Zebra mouse Muridae 2 2 Lophiomys imhausi African crested/maned rat Muridae 1 1 4 Camera survey The camera surveys detected many large mammals that were not amenable to live trapping. The cameras on the river grid recorded eight species representing six families (Table 3). This included two primates from the Cercopithecidae (Papio anubis and Erythrocebus patas). In addition, there were two members of the Bovidae (Syncerus caffer and Madoqua guentheri), one from the Leporidae (Lepus saxatilis), and one from the Elephantidae (Loxodonta africana). Two carnivores were recorded: one from the Hyaenidae (Crocuta crocuta) and one from the Herpestidae (Herpestes sanguinea). Table 3: Results of a camera-monitoring survey conducted at a river site within the Lolldaiga Hills Conservation Landscape, 22-27 February 2014. Species Common name Family Captures Individuals Papio anubis Olive baboon Cercopithecidae 6 26 Syncerus caffer Cape buffalo Bovidae 3 3 Madoqua guentheri Günther's dik-dik Bovidae 1 Loxodonta africana African elephant Elephantidae 1 Erythrocebus patas Patas monkey Cercopithecidae 2 3 Lepus saxatilis Scrub hare Leporidae 2 2 Herpestes sanguinea Slender mongoose Herpestidae 2 2 Crocuta croctua Spotted hyena Hyaenidae 4 4 On the dam grid, the cameras recorded eight species from four families (Table 4). This included four members of the Bovidae (Tragelaphus scriptus, Syncerus caffer, Raphicerus campestris, and Kobus ellipsiprymnus). Two members of the Hyaenidae were recorded (Crocuta crocuta and Hyaena hyaena), in addition to one member of the Leporidae (Lepus saxatilis) and one from the Elephantidae (Loxodonta africana). 5 Table 4: Results of a camera-monitoring survey conducted at a dam site within the Lolldaiga Hills Conservation Landscape, 23-28 February 2014. Species Common name Family Captures Individuals Tragelaphus scriptus Bushbuck Bovidae 1 1 Syncerus caffer Cape buffalo Bovidae 3 9 Loxodonta africana Elephant Elephantidae 1 7 Lepus saxatilis Scrub hare Leporidae 1 1 Crocuta crocuta Spotted hyena Hyaenidae 1 1 Raphicerus campestris Steinbuck Bovidae 1 1 Hyaena hyaena Striped hyena Hyaenidae 1 1 Kobus ellipsiprymnus Waterbuck Bovidae 1 3 CONCLUSIONS Each of the four individual surveys—camera and live trapping surveys at both grid sites—resulted in detections of eight species over the course of five sampling nights. A total of 14 species were live-trapped across the two grid sites, and game cameras detected a total of 12 species across both grid sites. Only one species, the slender mongoose (H. sanguinea) was detected using both methods, resulting in a total of 25 individual species detections across all the surveys at both sites (Table 5). Despite the equivalent species diversity (8 species) detected over the course of each survey, the species detected by the two methods at each site varied considerably, primarily due to the fact that large species cannot be live-trapped and small species easily evade detection by game cameras. These results indicate that the habitat diversity of the LHCL facilitates high species abundance. Of the 14 species detected via live trapping across the two grid sites, only two appeared at both of the sites. Only four of the 12 species detected by game cameras were present at both sites. It is clear that the diversity of habitats included within the borders of the LHCL facilitates the presence of a very diverse mammal assemblage. 6 Table 5: Summary of species detected using both live trapping and camera survey methods at the Lolldaiga Hills Conservation Landscape, 22-28 February 2014. Species Common Name Family Aethomys hindei Bush rat Muridae Arvicanthus niloticus Grass rat Muridae Crocidura sp. White-toothed shrew Soricidae Crocuta crocuta Spotted hyena Hyaenidae Erythrocebus patas Patas monkey Cercopithecidae Euxerus erythropus Striped ground squirrel Sciuridae Genetta maculata Blotched genet Viverridae Narrow-footed woodland Grammomys sp mouse Muridae Graphiurus sp African dormouse Gliridae