Impact of anthropogenic disturbance on the density and activity pattern of deer evaluated with respect to spatial scale-dependency

Abstract

Anthropogenic disturbance modifies various ecological traits of wildlife. The magnitude of the effects will change depending on spatial scale. Therefore, for wildlife conservation, the effective spatial scale at which the disturbance has the greatest effects on wild populations must be determined. This study examined the influence of anthropogenic disturbance on two ecological traits (population density and daily activity pattern) of deer. We quantified the effects of land use (broad-leaved forest, mixed coniferous/broad-leaved forest, natural grassland, subalpine vegetation, forestry area, and agricultural land), hunting risk, and densities of feral domestic dogs and wild monkeys. The effects of land use were analyzed at various spatial scales and a model selection procedure (generalized mixed model) was used to examine significant variables on the two ecological traits at each spatial scale. Combinations of selected variables differed with ecological traits and spatial scales. The spatial scale of the best model was defined as the most effective spatial scale for each ecological trait. Deer density was affected positively by areas of natural grassland and monkey density, and negatively by areas of forestry, mixed forest and agricultural land at the most effective spatial scale. For the daily activity pattern, larger areas of agricultural land, smaller natural grassland areas and higher hunting risk reduced diurnal and induced nocturnal activity. The most effective spatial scale explaining population density was smaller than that of daily activity pattern. This study showed that agricultural land, forestry areas and hunting risk affected deer ecology as anthropogenic disturbance. However, each disturbance factor modified different ecological traits or modified both ecological traits at different spatial scales. Detecting the appropriate spatial scales at which anthropogenic disturbance should be managed is essential for wildlife conservation. © 2013 Deutsche Gesellschaft für Säugetierkunde.