107 research outputs found
On the Move â Do Domestic and Wild Ungulate Species Distributions Overlap in the Mongolian Gobi?
In the Great Gobi B Strictly Protected Area (Great Gobi B), wild and domestic ungulates seasonally share the forage of the semi-desert and desert habitat. Around 130 herder families are grazing their livestock, mainly goats and sheep, in the protected area in winter. Wild ungulates of global significance in Great Gobi B include the reintroduced Przewalskiâs horse (Equus ferus przewalskii),which had previously been extinct in the wild. To determine potential habitat overlaps between Przewalskiâs horses and livestock, we mapped the movements of 19 livestock herds monitored via GPS collars and ranger observations of Przewalskiâs horse herds over a one year period from September 2018 to August 2019. We additionally conducted focus group interviews with nomadic herders about their rangeland management. We found that pasture use in and around the Great Gobi B is still following the nomadic tradition, with herders moving camp locations on average eleven times per year, depending on forage availability. Our results show that the range of Przewalskiâs horses and livestock mostly overlap around permanent and ephemeral water points. However, the same resources are used in different seasons. The protected area was recently expanded to twice its size, now also including additional herder households and traditional pastures. For the ongoing discussion about concerning the new zonation of the enlarged protected area it is important to consider both, herder and wildlife movements patterns, to meet the conservation goals of the protected area but also meet the needs of the traditional pastoral herding community
The Danger of Having All Your Eggs in One BasketâWinter Crash of the Re-Introduced Przewalski's Horses in the Mongolian Gobi
Large mammals re-introduced into harsh and unpredictable environments are vulnerable to stochastic effects, particularly in times of global climate change. The Mongolian Gobi is home to several rare large ungulates such as re-introduced Przewalski's horses (Equus ferus przewalskii) and Asiatic wild asses (Equus hemionus), but also to a millennium-old semi-nomadic livestock herding culture
Comparative parasitological examination on sympatric equids in the Great Gobi âBâ Strictly Protected Area, Mongolia
Subspecies hybridization as a potential conservation tool in species reintroductions
Reintroductions are a powerful tool for the recovery of endangered species. However, their longâterm success is strongly influenced by the genetic diversity of the reintroduced population. The chances of population persistence can be improved by enhancing the population's adaptive ability through the mixing of individuals from different sources. However, where source populations are too diverse the reintroduced population could also suffer from outbreeding depression or unsuccessful admixture due to behavioural or genetic barriers. For the reintroduction of Asiatic wild ass Equus hemionus ssp. in Israel, a breeding core was created from individuals of two different subspecies (E. h. onager & E. h. kulan). Today the population comprises approximately 300 individuals and displays no signs of outbreeding depression. The aim of this study was a population genomic evaluation of this conservation reintroduction protocol. We used maximum likelihood methods and genetic clustering analyses to investigate subspecies admixture and test for spatial autocorrelation based on subspecies ancestry. Further, we analysed heterozygosity and effective population sizes in the breeding core prior to release and the current wild population. We discovered high levels of subspecies admixture in the breeding core and wild population, consistent with a significant heterozygote excess in the breeding core. Furthermore, we found no signs of spatial autocorrelation associated with subspecies ancestry in the wild population. Inbreeding and variance effective population size estimates were low. Our results indicate no genetic or behavioural barriers to admixture between the subspecies and suggest that their hybridization has led to greater genetic diversity in the reintroduced population. The study provides rare empirical evidence of the successful application of subspecies hybridization in a reintroduction. It supports use of intraspecific hybridization as a tool to increase genetic diversity in conservation translocations
Emergent Properties of Patch Shapes Affect Edge Permeability to Animals
Animal travel between habitat patches affects populations, communities and ecosystems. There are three levels of organization of edge properties, and each of these can affect animals. At the lowest level are the different habitats on each side of an edge, then there is the edge itself, and finally, at the highest level of organization, is the geometry or structure of the edge. This study used computer simulations to (1) find out whether effects of edge shapes on animal behavior can arise as emergent properties solely due to reactions to edges in general, without the animals reacting to the shapes of the edges, and to (2) generate predictions to allow field and experimental studies to test mechanisms of edge shape response. Individual animals were modeled traveling inside a habitat patch that had different kinds of edge shapes (convex, concave and straight). When animals responded edges of patches, this created an emergent property of responding to the shape of the edge. The response was mostly to absolute width of the shapes, and not the narrowness of them. When animals were attracted to edges, then they tended to collect in convexities and disperse from concavities, and the opposite happened when animals avoided edges. Most of the responses occurred within a distance of 40% of the perceptual range from the tip of the shapes. Predictions were produced for directionality at various locations and combinations of treatments, to be used for testing edge behavior mechanisms. These results suggest that edge shapes tend to either concentrate or disperse animals, simply because the animals are either attracted to or avoid edges, with an effect as great as 3 times the normal density. Thus edge shape could affect processes like pollination, seed predation and dispersal and predator abundance
Effects of body size on estimation of mammalian area requirements.
Accurately quantifying species' area requirements is a prerequisite for effective area-based conservation. This typically involves collecting tracking data on species of interest and then conducting home range analyses. Problematically, autocorrelation in tracking data can result in space needs being severely underestimated. Based on the previous work, we hypothesized the magnitude of underestimation varies with body mass, a relationship that could have serious conservation implications. To evaluate this hypothesis for terrestrial mammals, we estimated home-range areas with global positioning system (GPS) locations from 757 individuals across 61 globally distributed mammalian species with body masses ranging from 0.4 to 4000 kg. We then applied blockcross validation to quantify bias in empirical home range estimates. Area requirements of mammals 1, meaning the scaling of the relationship changedsubstantially at the upper end of the mass spectrum
Behavioral responses of terrestrial mammals to COVID-19 lockdowns
COVID-19 lockdowns in early 2020 reduced human mobility, providing an opportunity to disentangle its effects on animals from those of landscape modifications. Using GPS data, we compared movements and road avoidance of 2300 terrestrial mammals (43 species) during the lockdowns to the same period in 2019. Individual responses were variable with no change in average movements or road avoidance behavior, likely due to variable lockdown conditions. However, under strict lockdowns 10-day 95th percentile displacements increased by 73%, suggesting increased landscape permeability. Animals' 1-hour 95th percentile displacements declined by 12% and animals were 36% closer to roads in areas of high human footprint, indicating reduced avoidance during lockdowns. Overall, lockdowns rapidly altered some spatial behaviors, highlighting variable but substantial impacts of human mobility on wildlife worldwide.acceptedVersio
Behavioral responses of terrestrial mammals to COVID-19 lockdowns
COVID-19 lockdowns in early 2020 reduced human mobility, providing an opportunity to disentangle its effects on animals from those of landscape modifications. Using GPS data, we compared movements and road avoidance of 2300 terrestrial mammals (43 species) during the lockdowns to the same period in 2019. Individual responses were variable with no change in average movements or road avoidance behavior, likely due to variable lockdown conditions. However, under strict lockdowns 10-day 95th percentile displacements increased by 73%, suggesting increased landscape permeability. Animals' 1-hour 95th percentile displacements declined by 12% and animals were 36% closer to roads in areas of high human footprint, indicating reduced avoidance during lockdowns. Overall, lockdowns rapidly altered some spatial behaviors, highlighting variable but substantial impacts of human mobility on wildlife worldwide.acceptedVersio
Moving in the anthropocene: global reductions in terrestrial mammalian movements
Animal movement is fundamental for ecosystem functioning and species survival, yet the effects of the anthropogenic footprint on animal movements have not been estimated across species. Using a unique GPS-tracking database of 803 individuals across 57 species, we found that movements of mammals in areas with a comparatively high human footprint were on average one-half to one-third the extent of their movements in areas with a low human footprint. We attribute this reduction to behavioral changes of individual animals and to the exclusion of species with long-range movements from areas with higher human impact. Global loss of vagility alters a key ecological trait of animals that affects not only population persistence but also ecosystem processes such as predator-prey interactions, nutrient cycling, and disease transmission
To eat or not to eat? The diet of the endangered iberian wolf (Canis lupus signatus) in a human- dominated landscape in central Portugal
Livestock predation by large carnivores and their persecution by local communities are
major conservation concerns. In order to prevent speculations and reduce conflicts, it is crucial
to get detailed and accurate data on predatorsâ dietary ecology, which is particularly important
in human dominated landscapes where livestock densities are high. This is the case
of the endangered Iberian wolf in Portugal, an endemic subspecies of the Iberian Peninsula,
which has seen its population distribution and abundance decline throughout the 20th century.
Accordingly, the diet of the Iberian wolf was analyzed, using scat analysis, in a humanized
landscape in central Portugal. From 2011 to 2014, a total of 295 wolf scats were
collected from transects distributed throughout the study area, prospected on a monthly
basis. Scat analysis indicated a high dependence of Iberian wolf on livestock. Domestic
goat predominated the diet (62% of the scats), followed by cow (20%) and sheep (13%); the
only wild ungulate present in the scat analysis was the wild boar (4% of the scats). Our results
show that even though livestock constitute most part of wolves diet, different livestock
species may represent different predation opportunities. We conclude that the high levels
of livestock consumption may be a result of low diversity and density of wild ungulates
that settles livestock as the only abundant prey for wolves. Our findings help on the understanding
of the Iberian wolf feeding ecology and have implications for conflict management
strategies. Finally, management implications are discussed and solutions are
recommended
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