Abundance Of Terrestrial Mammals Research Articles

First photographic evidence of Indian Pangolin Manis crassicaudata Geoffroy, 1803 (Mammalia: Pholidota: Manidae), in Colonel Sher Jung National Park, Himachal Pradesh, India

The Indian Pangolin Manis crassicaudata is ‘Endangered’ on the IUCN Red List. We report the first photographic evidence of its presence in Colonel Sher Jung National Park of Paonta Valley in Himachal Pradesh. Camera-traps (n = 64) were used to assess the diversity and abundance of terrestrial mammals. Over 1,912 trap nights, we documented 16 mammals, of which the Indian Pangolin was photo-captured at a single camera-trap station with two independent records. Although the presence of species has been indicated in a few studies conducted in the study area, no photographic evidence of the Indian Pangolin from the National Park has previously been reported. We strongly recommend additional fieldwork in and around the protected area to learn more about the Indian Pangolin’s distribution, habitat use, and ecology.

First photographic record of marbled cat Pardofelis marmorata Martin, 1837 (Mammalia, Carnivora, Felidae) in Nepal

The marbled catPardofelismarmoratais a Near Threatened small felid. The cat’s presence in Nepal is based on an anecdote. A camera trap-based study to access diversity and abundance of terrestrial mammals in eastern Nepal accumulated 3,014 camera trap days and resulted in 5,176 photographs of 17 medium-large sized mammal species. Amongst them, a marbled cat was captured at a single camera trap station in January 2018. The camera trap-capturing the marbled cat was located in the secondary forest at an altitude of 2,750 m a.s.l., dominated by free-ranging cattle close to a permanent human settlement (1.4 km) and a temporary cattle herding camp (0.4 km). This is the first photographic evidence of a marbled cat in Nepal. In this survey, we also recorded three other felid species: common leopardPantherapardus, Asiatic golden-catCatopumatemminckiiand leopard catPrionailurusbengalensis. We recommend detailed year-round camera trap surveys in the mid-hills of eastern Nepal along with research on adaptation of the small felids to human-dominated areas and assessment of immediate threats for preparing sound conservation management plans of the marbled cat and its sympatric species. Initiation of conservation programmes engaging localdokpa(herders) is necessary.

Evaluating spatiotemporal trends in terrestrial mammal abundance using data collected during bird surveys

Information on the status of biodiversity is crucial for species conservation and management. Large scale assessments are only feasible through citizen science but some taxa are poorly monitored because few people specialise in them. We explore alleviating this problem by using data collected for poorly monitored species as an add-on to existing bird surveys. Since 1995, participants in the annual Breeding Bird Survey have recorded the abundance of mammals during their surveys. We demonstrate the value of these data by developing spatial models of relative abundance for nine common and easily detected mammal species. Rabbit, brown hare and mountain hare all showed widespread declines. Conversely, deer showed increases throughout their ranges, with the exception of the red deer whose population was predominantly stable. The grey squirrel continues to increase in several areas. The red fox, the only carnivore with enough data, showed significant large declines. The collection of data on taxa other than the primary target has particular merit where the secondary taxa can be detected effectively by methods devised for the core survey. In such cases the data are inexpensive and inherit some of the benefits of the underlying structure and power of the core survey. However, the efficacy of the primary study design may vary for the members of secondary taxa and may not be temporally or spatially suitable for all of them. Although more volunteer training may be required, there are also opportunities to engage and enthuse people about conservation issues of other species groups.

Long-term variation in abundance of terrestrial mammals and birds in eastern Ecuador as measured by photographic rates and occupancy estimates

Long-term studies from undisturbed forests provide a baseline by which to assess impacts of human activities, including climate change, on vertebrate population dynamics in lowland tropical forests. We use cameratrap data from January to March, 2005 to 2015, to examine patterns of variation in numbers of images and occupancy (proportion of cameras where images of a species were obtained), variables that may reflect changes in abundance or activity patterns of terrestrial mammals and birds in an undisturbed lowland forest of eastern Ecuador. We accumulated 1,961 independent records of 31 mammal species and 427 images of 17 bird species during 5,547 trap-days. Number of mammal species ranged from 15 to 25 per year (107 to 466 images), whereas birds ranged from 3 to 11 species per year (10 to 122 images). Capture rates varied both among species and among years but showed no evidence of declines; populations of several species appeared to increase (Priodontes maximus, Dasypus novemcinctus, Pecari tajacu, and Dasyprocta fuliginosa). Similarly, occupancy rates provided no indication of consistent declines; occupancy rates increased significantly for D. fuliginosa, D. novemcinctus, and P. maximus. There was no indication that variation in either capture rates or occupancy was related to variation in large-scale climate trends as represented by the Southern Oscillation Index. Results suggest that populations of most species that are well sampled by camera traps have remained relatively stable over 11 years. Long-term studies from other regions in the tropics are needed to evaluate the generality of this pattern.

Impact of land use on occupancy and abundance of terrestrial mammals in the Drakensberg Midlands, South Africa

Better management and knowledge regarding the effect of land use intensification on mammal abundance and occupancy is crucial for species conservation. This is particularly true in dynamic forest-farmland mosaics subjected to rapid human-induced habitat alterations for agricultural practices. We conducted camera-trap surveys at 44 locations across farmland use gradients between October 2012 and January 2013. We estimated occupancy and relative abundance of 10 terrestrial mammals in response to farmland use in the Drakensberg Midlands, South Africa. Occupancy modelling revealed the importance of available forest and wetland to several mammals. Occupancy estimates for Leptailurus serval were lower in cropland than for Herpestes ichneumon, Atilax paludinosus and Potamochoerus larvatus. Occupancy of Leptailurus serval and Redunca rundinu increased with relative human abundance while the relationship was inverse for Hystrix cristata and Potamochoerus larvatus. Livestock-related activity influenced occupancy of Potamochoerus larvatus positively and Hystrix cristata negatively. Pesticide usage had a negative impact on detection of several mammals, and occupancy of Atilax paludinosus. Commercial plantation influenced occupancy of Tragelaphus scriptus and Potamochoerus larvatus positively. Plantation supported the abundance of five species positively. Wetland influenced relative abundance of Leptailurus serval positively. Pesticide use significantly decreased relative abundance of Leptailurus serval and Atilax paludinosus. Livestock and human relative abundance were positively associated with relative abundance of Leptailurus serval and Canis mesomelas and negatively for other species. Our models proved the sensitivity of some mammals towards the natural habitat loss due to agricultural practices while others appeared to be tolerant to such human-modified habitats. We suggest feasible management implications for conserving diverse mammalian assemblages in farmland mosaics.

Variation in terrestrial mammal abundance on pastoral and conservation land tenures in north‐eastern Australian tropical savannas

AbstractThe introduction of domestic cattle into systems that have had little historical grazing by large herbivores, such as the case in Australia, can lead to both direct and indirect changes in native flora and fauna. In this study, we investigate the differences in native mammal abundance between pastoral land managed for cattle production and conservation land in Australian tropical savannas. We systematically sampled 68 sites for mammals in north‐eastern Queensland representing the two land tenures, which represent land with introduced stock and native herbivores present, and land where only native herbivores occur. We recorded 17 species of mammals representing five families and two functional groups (small mammals and macropods). Generalized linear mixed effects models identified that there was a significant positive relationship between increasing total ground cover and small mammal abundance and also the abundance of two species, Pseudomys desertor and P. gracilicaudatus. We recorded a reduction in abundance on pastoral land for macropods and small mammals, and four species, M. robustus, M. rufus, Leggadina lakedownensis, P. gracilicaudatus. Total ground cover and perennial grass cover was lower on pastoral land. Small mammal abundance on pastoral land was less even with increasing ground cover. Our results suggest that on pastoral land, native mammal abundance is affected and this has some relationship to ground cover changes. We recognize that there are other confounding management differences between pastoral and conservation lands such fire use, dingo baiting, and the manner of weed invasion and control that could influence mammal pattern. We conclude that conservation strategies for mammals in Australia's tropical savannas need to include a variety of land management schemes and tenures including land free from grazing by domestic livestock.

Response of wild mammals to seasonal shrinking-and-expansion of habitats due to flooding regime of the Pantanal, Brazil

The Pantanal is a large savanna wetland (138,183 km2 in Brazil), important for its wildlife, fed by tributaries of the upper Paraguay River, center of South America (Brazil, touching Bolivia and Paraguay). Uplands are plateaus (250-1,200 m high, 215,000 km2 in Brazil) and flatland is the Pantanal (80-150 m high, 147,574 km2 in Brazil). Rivers are slow moving when they meet the flatland (slope 0.3-0.5 m/km east-west; 0.03-0.15 m/km north-south), periodically overflowing their banks, creating a complex seasonal habitat range. Recurrent shallow flooding occupies 80% of the Pantanal; during the dry season flooded areas dry up. Fluctuating water levels, nutrients and wildlife form a dynamic ecosystem. A flooding regime forms distinct sub-regions within the Pantanal. A mammal survey was carried out in the sub-region of the Rio Negro from April, 2003 through March, 2004 to study the diversity and abundance of terrestrial mammals during the dry and flooding seasons. A total of 36 species were observed in the field. The capybara Hydrochaeris hydrochaeris was the most frequent species, followed by the crab-eating-fox Cerdocyon thous and the marsh deer Blastocerus dichotomus. The highest abundance of species was observed during the dry season (August and September), when there is a considerable expansion of terrestrial habitats, mainly seasonally flooded grassland. Animal abundance (in terms of observed individual frequencies) varied during the dry and wet seasons and the seasonally flooded grassland was the most utilized habitat by mammals in the dry season.