scholarly journals Estimating population densities and biomass of ungulates in the temperate ecosystem of Bhutan

Oryx ◽  
2010 ◽  
Vol 44 (3) ◽  
pp. 376-382 ◽  
Author(s):  
Sonam Wangyel Wang

AbstractIn this study I estimate population densities and biomass of the major prey species of tiger Panthera tigris, leopard Panthera pardus and dhole Cuon alpinus in Bhutan’s temperate ecosystem and recommend measures for reducing crop damage whilst simultaneously protecting ungulate populations. Thirty-two transects totalling 849 km were walked to estimate densities and biomass of ungulates and primates in Bhutan’s Jigme Singye Wangchuck National Park during 2005–2006. Adequate detections (> 40 sightings) for analysis using Distance were obtained for wild pig Sus scrofa (n = 54), muntjac Munticus muntjac (n = 102) and sambar Cervus unicolor (n = 48). Because of similarity in morphology and habitat use, density of serow Capricornis sumatraensis was estimated using the detection probability for sambar. Detections for langur Trachypithecus geei and macaque Macca mulatta were combined (n = 39) to estimate primate density. Mean estimated densities were 3.68 wild pig, 2.17 muntjac, 1.19 sambar, 2.37 primates and 0.36 serow km-2. The three primary prey species of large predators, wild pig, sambar and muntjac, provided a biomass of 379 kg km-2, which could support up to 1.2 tigers per 100 km2. However, the presence of other sympatric carnivores competing for prey in the same area suggests that the actual number of tigers that could be supported is lower. Livestock (density, 6.0 km-2; biomass, 615 kg km-2) apparently supplement prey availability. Ungulate density in the study area is generally low compared to other areas in the Indian sub-continent, and this may be due to conflicts with farmers, excessive grazing of livestock in the forest and the rugged terrain.

2017 ◽  
Vol 3 (1) ◽  
pp. 80-84 ◽  
Author(s):  
Shivish Bhandari ◽  
Mukesh Kumar Chalise ◽  
Chiranjibi Prasad Pokharel

AbstractWe studied the diet of the Bengal tigers (Panthera tigris tigris) in Chitwan National Park, Nepal, by identifying 109 prey items from 85 tiger scats. Tigers in this region fed upon eight different mammal species. Chital (Axis axis) was the major prey with a frequency of 45% of the Tigers’ diet. The occurrence of other prey species included sambar (Cervus unicolor, 23%), wild pig (Sus scrofa, 15%), hog deer (Axis porcinus, 9%), barking deer (Muntiacus muntjak, 4%), and gaur (Bos gaurus, 2%). Tigers also hunted livestock, but this prey comprised a small component of the relative biomass (buffalo 5% and cow 2%). Our study suggests that the tiger depends mostly upon wild prey for its subsistence in the Chitwan National Park, but will also sporadically hunt livestock.


2020 ◽  
Vol 43 ◽  
pp. 65-73
Author(s):  
MA Aziz ◽  
MA Islam ◽  
J Groombridge

The Sundarbans is the only mangrove habitat in the world to support tigers Panthera tigris, whose persistence there is believed to be dependent on a very limited number of prey species. Conservation managers therefore need to understand how tigers utilise available prey species on a spatial scale in order to formulate a prey-based protection strategy for this global-priority tiger landscape. A total of 512 scat samples were collected during a survey of 1984 km2 of forest across 4 sample blocks in the 6017 km2 of the Bangladesh Sundarbans. Analysis of scat composition and prey remains reliably identified 5 major prey species, of which spotted deer Axis axis and wild pig Sus scrofa contributed a cumulative biomass of 89% to tiger diet. Tiger preference for prey species was highly skewed towards spotted deer and wild pig, but the relative contribution of these 2 species differed significantly across the 4 study areas, which spanned the Sundarbans, demonstrating important spatial patterns of tiger prey preference across the Sundarbans landscape. Given the comparatively limited number of prey species available to support the dwindling tiger population, different strategies are needed in different parts of the Sundarbans to support tiger populations and to protect spotted deer and wild pig populations from unabated poaching.


2016 ◽  
Vol 3 (8) ◽  
pp. 160252 ◽  
Author(s):  
Christopher Wolf ◽  
William J. Ripple

Large terrestrial carnivores are an ecologically important, charismatic and highly endangered group of species. Here, we assess the importance of prey depletion as a driver of large carnivore endangerment globally using lists of prey species for each large carnivore compiled from the literature. We consider spatial variation in prey endangerment, changes in endangerment over time and the causes of prey depletion, finding considerable evidence that loss of prey base is a major and wide-ranging threat among large carnivore species. In particular, the clouded leopard ( Neofelis nebulosa ), Sunda clouded leopard ( Neofelis diardi ), tiger ( Panthera tigris ), dhole ( Cuon alpinus ) and Ethiopian wolf ( Canis simensis ) all have at least 40% of their prey classified as threatened on the International Union for the Conservation of Nature (IUCN) Red List and, along with the leopard ( Panethra pardus ), all of these species except the Ethiopian wolf have at least 50% of their prey classified as declining. Of the 494 prey species in our analysis, an average of just 6.9% of their ranges overlap protected areas. Together these results show the importance of a holistic approach to conservation that involves protecting both large carnivores directly and the prey upon which they depend.


Oryx ◽  
2013 ◽  
Vol 47 (4) ◽  
pp. 544-552 ◽  
Author(s):  
Chanthavy Vongkhamheng ◽  
Arlyne Johnson ◽  
Melvin E. Sunquist

AbstractLarge ungulates across South-east Asia have been experiencing a rapid decline in recent decades because of overexploitation by humans. An absence of reliable data on the abundance and distribution of ungulates makes it difficult to assess the effectiveness of conservation efforts to recover their populations. As the principal prey for Endangered tigers Panthera tigris, depletion of wild ungulates is a major threat to the species' persistence and recovery across its range. This study estimated abundance and distribution of five ungulate taxa using a grid-based occupancy survey across a 3,000 km2 core zone within the 5,950 km2 Nam Et–Phou Louey National Protected Area in northern Lao. The results show an abundance index of 5.29 ± 0.30 ungulates per km2, with muntjac Munticus spp. and wild pig Sus spp. being most common, moderate levels of serow Capricornis milneedwardsii and sambar Cervus unicolor but few gaur Bos gaurus. This low abundance of medium- and large-sized ungulates at the site strongly suggests that strict control of hunting of these ungulates is important for securing their long-term survival as well as that of the tiger population that depends on them, which is currently the only known breeding population remaining in Indochina.


2019 ◽  
Vol 46 (7) ◽  
pp. 628
Author(s):  
Chidanand S. Reddy ◽  
Reuven Yosef ◽  
Gianpiero Calvi ◽  
Lorenzo Fornasari

Abstract ContextTiger (Panthera tigris), leopard (Panthera pardus) and dhole (Cuon alpinus) represent a typical multi-predator system of species of conservation concern. Several studies have addressed this system, with heterogeneous results, and there’s a lack of information on population dynamics of multi-species assemblages. We studied a time series (1998–2009) of abundance indices for three predators and five prey species in Bor Wildlife Sanctuary (BWS), Maharashtra, India, before it was declared as Bor Tiger Reserve (BTR) in 2009. AimsTo analyse the complex relationships within a predator–prey system in a dynamic fashion, to analyse data collected in a stable and undisturbed area and to form a comparison basis for future studies within the sanctuary after its declaration as a Tiger Reserve. MethodsA 24-h effort was made annually to census the BWS. Predators were counted at waterholes from arboreal hideouts. The prey populations were censused along 353-km line-transects. For each species, we analysed the yearly growth rate, testing the effect of inter-species abundance. Key resultsTiger growth rate did not depend on any particular prey, whereas mesopredators seemed to depend on medium-sized prey. A die-out of dholes in 2001 was followed by an increase in tiger populations (from 4 to 11), which, in turn, negatively affected leopard numbers (from 6 to 2).We found no direct evidence of top-down effect, but the density dependence for three of five prey species could be linked to predation pressure. We found some evidence of interspecific competition among prey species, especially among ungulates, potentially being mediated by predation pressure. ConclusionsThe relationships among species in a predator–prey system are very complex and often could be explained only by more-than-two-species interactions. The disappearance of one predator, not necessarily the top predator, could bring multiple effects, for which it could be difficult to detect causal relationships. ImplicationsAll subsequent changes in human activities in the sanctuary, as a consequence of its designation as the BTR in 2009, should be evaluated with respect to the results of the present study. The conservation of large predators should rely on the maintenance of a rich and abundant prey base, in which different-sized prey could lessen interactive-competition among the predators.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bryan Andrew Lazarus ◽  
Azlan Che-Amat ◽  
Muhammad Muzammil Abdul Halim Shah ◽  
Azwan Hamdan ◽  
Hasliza Abu Hassim ◽  
...  

AbstractNatural salt lick (sira) is a strategic localisation for ecological wildlife assemblage to exhibit geophagy which may act as a population dynamic buffer of prey and predators. Undoubtedly, many agree that geophagy at natural licks is linked to nutritional ecology, health and assembly places facilitating social interaction of its users. Overall, natural salt licks not only save energy of obtaining nutrient leading to health maintenance but also forms the basis of population persistence. The Royal Belum Rainforest, Malaysia (Royal Belum) is a typical tropical rainforest in Malaysia rich in wildlife which are mainly concentrated around the natural salt lick. Since this is one of the most stable fauna ecology forest in Malaysia, it is timely to assess its impact on the Malayan tiger (Panthera tigris) home range dynamics. The three-potential home ranges of the Malayan tiger in this rainforest were selected based on animal trails or foot prints surrounding the salt lick viz (e.g. Sira Kuak and Sira Batu; Sira Rambai and Sira Buluh and Sira Papan) as well as previous sightings of a Malayan tiger in the area, whose movement is dependent on the density and distribution of prey. Camera traps were placed at potential animal trails surrounding the salt lick to capture any encountered wildlife species within the area of the camera placements. Results showed that all home ranges of Malayan tiger were of no significance for large bodied prey availability such as sambar deer (Rusa unicolor), and smaller prey such as muntjacs (Muntiacus muntjac) and wild boar (Sus scrofa). Interestingly, all home range harbour the Malayan tiger as the only sole predator. The non-significance of prey availability at each home range is attributed to the decline of the Malayan tiger in the rainforest since tigers are dependant on the movement of its preferred prey surrounding natural salt licks. Thus, the information from this study offers fundamental knowledge on the importance of prey-predator interaction at salt lick which will help in designing strategy in rewilding or rehabilitation programs of the Malayan tiger at the Royal Belum Rainforest.


Oryx ◽  
2013 ◽  
Vol 47 (3) ◽  
pp. 420-426 ◽  
Author(s):  
Kae Kawanishi ◽  
Gopalasamy Reuben Clements ◽  
Melvin Gumal ◽  
Gareth Goldthorpe ◽  
Mohd Nawayai Yasak ◽  
...  

AbstractTiger Panthera tigris populations are under threat from poaching and depletion of their prey populations. The National Tiger Action Plan for Malaysia contains several actions addressing the threat of legal and illegal hunting of tiger prey species. One action in this plan required an investigation of whether urgent policy changes were needed to improve the protection of the prey of tigers, based on existing data. As the lack of reliable baseline data prevented us from determining population trends accurately, we compiled camera-trapping data from 23 studies conducted between 1997 and 2008 on four principal tiger prey species (sambar Rusa unicolor, barking deer Muntiacus muntjac, wild boar Sus scrofa and bearded pig S. barbatus) and two potential prey species (gaur Bos gaurus and Malayan tapir Tapirus indicus) and compared their distributions and relative abundances. From 10,145 wildlife photographs spanning 40,303 trap-nights, sambar, bearded pig and gaur appeared to be most threatened given their restricted distribution and low relative abundance. Among these, the gaur has full legal protection and has received more conservation attention than the other two species. Following our assessment and advocacy a 6-year moratorium on hunting both sambar and barking deer was imposed by the Malaysian government and the highest protection status possible was afforded the bearded pig. This case study illustrates how best available data (BAD), in this case from camera-trapping studies, can be harnessed to effect precautionary policy changes to curb the impacts of hunting on threatened predator and prey populations that could crash well before resources would otherwise be available for rigorous scientific assessments.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3014 ◽  
Author(s):  
Peter Caley ◽  
Geoffrey R. Hosack ◽  
Simon C. Barry

Wildlife collision data are ubiquitous, though challenging for making ecological inference due to typically irreducible uncertainty relating to the sampling process. We illustrate a new approach that is useful for generating inference from predator data arising from wildlife collisions. By simply conditioning on a second prey species sampled via the same collision process, and by using a biologically realistic numerical response functions, we can produce a coherent numerical response relationship between predator and prey. This relationship can then be used to make inference on the population size of the predator species, including the probability of extinction. The statistical conditioning enables us to account for unmeasured variation in factors influencing the runway strike incidence for individual airports and to enable valid comparisons. A practical application of the approach for testing hypotheses about the distribution and abundance of a predator species is illustrated using the hypothesized red fox incursion into Tasmania, Australia. We estimate that conditional on the numerical response between fox and lagomorph runway strikes on mainland Australia, the predictive probability of observing no runway strikes of foxes in Tasmania after observing 15 lagomorph strikes is 0.001. We conclude there is enough evidence to safely reject the null hypothesis that there is a widespread red fox population in Tasmania at a population density consistent with prey availability. The method is novel and has potential wider application.


2021 ◽  
Vol 912 (1) ◽  
pp. 012105
Author(s):  
E Jumilawaty ◽  
N Namira ◽  
A Anggelicha ◽  
A Hartanto

Abstract Cattle egret (Bubulcus ibis) is a widespread avian species inhabiting a variety of natural and artificial sites. Asam Kumbang Crocodile Park is one of establishments that occupied some portions of B. ibis habitat with no recent information on the food resource and prey availability for the viability of B. ibis. To this aim, we collected 10 random individuals of B. ibis to be sacrificed for gut content analysis of prey species. A total of 19 taxa was found as prey items in the gut of B. ibis with the dominant group from insects (Orthoptera, Scolopendromorpha). The diversity of prey species was categorized as moderate with intraspecific diet variation which formed four guilds that fed on specific taxa namely Group 1 (Haplotaxida, Lepidoptera, Anurans), Group 2 (Blattodea, Coleoptera, Araneae), Group 3 (Orthoptera, Scolopendromorpha); and Group 4 (Dermaptera, Squamata). Oxya chinensis and Oxya velox are important rice grasshopper pests that were also found in the gut of B. ibis reflecting their potential function as biological control agent.


1988 ◽  
Vol 66 (2) ◽  
pp. 334-344 ◽  
Author(s):  
K. G. Poole ◽  
D. A. Boag

Diet and aspects of feeding behaviour in a population of gyrfalcons (Falco rusticolus) in the Northwest Territories were examined between 1984 and 1986. Three prey species, rock ptarmigan (Lagopus mutus), arctic ground squirrel (Spermophilus parryii), and arctic hare (Lepus arcticus), composed 96.5% of total prey biomass identified. Ptarmigan and hares were taken in May and June of all years (98.2% of biomass). Juvenile squirrels were used extensively in July and August of 1984 and 1985 but not in 1986, when squirrel production fell to almost zero; ptarmigan continued to be the dominant prey species throughout that summer. Because densities of breeding ptarmigan remained relatively constant during the study, but those of juvenile ground squirrels did not, it appeared that gyrfalcons responded functionally to varying availability of prey. Mean weight (250 g) of prey taken by male gyrfalcons was significantly less than the weight (330 g) of prey taken by females. As predicted by optimal foraging theory, average size of prey brought to the nest increased as time away from the nest increased. Conditions of food abundance were observed at most nests, suggesting that the amount of food available during the nestling period was not limiting production. We suggest that annual production is a function of spacing of pairs, which is set during courtship and prelaying, when prey availability is at its yearly low and when males must forage for both members of the pair. The fact that most gyrfalcon pairs initiated laying only after the spring arrival of migrating ptarmigan is consistent with this conclusion.


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