M. van 't Zelfde

An expert habitat suitability model for the disaggregation of bird survey data: Bird counts in the Netherlands downscaled from atlas block to kilometre cell

Fauna distribution data are often inadequate for the purposes of physical planning at a national scale, because of their lack of detail or incomplete spatial coverage. A method is presented in which an expert habitat suitability model is used for data disaggregation, the opposite of aggregation, and interpolation. Using this method, in this article the data on breeding birds available in the Landscape Ecological Mapping of the Netherlands (LKN) database have been downscaled from atlas blocks to kilometre cells and validated for 14 species with contrasting ecologies. The first step in this procedure is definition of the ecological profile of each species, comprising its habitat requirements and its sensitivity to disturbance. A limited number of conditioning habitat factors are used to describe the ecological profile. The ecological profile is based mainly on expert judgement. The second step involves deriving the habitat characteristics of each kilometre cell that are compatible with the habitat requirements. By comparing the ecological profile with the habitat characteristics of each grid cell, the habitat suitability of every kilometre cells is established. The third step comprises completion and modification of the distribution data. The main change involves an estimation of numbers, based on interpolation, for those atlas blocks for which only the presence of a species has been established. The final step is disaggregation of the counted and interpolated atlas block data over the 25 constituent kilometre cells on the basis of the suitability of each cell. For each step of the disaggregation method, tables and maps of the results are presented. The limitations of the model and of the dataset used are considered and some promising applications of the method discussed.

Wild versus domestic prey in the diet of reintroduced tigers (Panthera tigris) in the livestock-dominated multiple-use forests of Panna Tiger Reserve, India

Grazing livestock in openly accessible areas is a common practice in the multiple-use forests of India; however, its compatibility with the reintroduction of tigers to these areas requires examination. Here, we investigated the diet of tigers in a livestock-dominated multiple-use buffer zone of the Panna Tiger Reserve, India. We hypothesised that the presence of feral cattle, along with open-access grazing practices in multiple-use forests, would increase the incidence of predation on livestock by tigers, even when wild prey are available. We used generalised linear models to test whether predation of livestock versus wild animals was influenced by (1) the sex and age class of tigers, (2) season, and (3) the distance of prey from the core-zone boundary of the reserve. Overall, sub-adult tigers and male tigers killed more livestock than wild prey, even when wild prey was available. In the winter and rainy seasons livestock were killed in higher numbers in the buffer zone than in summers, this may be because of the seasonally changing livestock herding patterns in the area. Further, with increasing distance from the core-zone boundary, all tigers killed more livestock, possibly because livestock were more easily accessible than wild prey. Our results show that open-access and unregulated livestock grazing is not currently compatible with large carnivore conservation in the same landscape. Such practices will lead to an increase in negative tiger-human-livestock interactions. In conclusion, we suggest the need to encourage locals to corral valuable cattle, leaving feral/unwanted livestock for tigers. This simple strategy would benefit both local inhabitants and tiger conservation in the multiple-use forests of India.

New insights into the factors influencing movements and spatial distribution of reintroduced Bengal tigers (Panthera tigris tigris) in the human-dominated buffer zone of Panna Tiger Reserve, India

Abstract The influence of tiger-specific (sex, age group), environmental (seasons, photoperiod) and anthropogenic (human use regimes) factors on the movements and spatial distribution of tigers using the human-dominated buffer zone of the Panna Tiger Reserve, India was studied. Generalised linear mixed models were used to test the significance of the relationships between the covariates influencing tiger presence. We report that tiger-specific factors – age group (generation) and sex – and environmental factors – seasons and day/night – significantly explain the observed variations in tiger use of the human-dominated buffer zone. For instance, second-generation tigers (sub-adults) spent 40% of their time in the human-use areas, compared to 10% spent by first-generation tigers (adult). When in human-use areas, sub-adult tigers approached areas near villages and spent 30% less time in areas close to water than adult tigers. Our study concludes that, in addition to tiger-specific factors, human factors, including livestock practices and peoples’ activities, influence tiger behaviour and their use of shared spaces. These unchecked human practices may lead to increased negative tiger-human interactions and restricts tigers from exploiting the resources in multiple-use areas.