Feeding patterns by roe deer and rabbits on pine, willow and birch in relation to spatial arrangement

Abstract

2005. Feeding patterns by roe deer and rabbits on pine, willow and birch in relation to spatial arrangement. Á/ Oikos 109: 513 Á/520.The location of a plant and its association with the surrounding vegetation may be a strong determinant of herbivore foraging decisions. The attractiveness of a food plant may be reduced if associated with a less preferred one (repellent Á/plant hypothesis) or, conversely, it may escape herbivory via association with a more preferred species (attractant Á/decoy hypothesis). In this study we tested the hypothesis that selection of the same food plants by two herbivore species with different body mass, i.e. roe deer and rabbits, is affected by the spatial disposition of preferred plants in relation to less preferred ones. We planted willows, birches and pines, representing food species of higher, intermediate and lower preference, respectively, in different spatial arrangements, to manipulate patch quality and accessibility to herbivores. Contrasting patches were constructed by planting willows or pines in the midst of birches and single-species arrays of all three species, in a blocked design, replicated six times in an area occupied by both roe deer and rabbits. Preference patterns were studied by recording browsing on current years' shoots and older plant parts. Across all trees in the experiment, we confirmed that roe deer clearly preferred willow over birch, pine was not browsed at all. There was greater herbivory by roe deer on birches occurring peripherally in an array, when the associated central species was willow or pine, as compared to birches in a single-species birch patch. Therefore food choices by roe deer appear to be determined by both patch and individual level selection. The rabbits only showed preference at a species level and did not respond to spatial arrangement of trees. The results from this study indicate that the location and association of trees can strongly affect foraging patterns of roe deer, but not in a manner wholly consistent with the repellent Á/plant or the attractant Á/decoy hypotheses.

Palatability mapping: a koala's eye view of spatial variation in habitat quality

“…The associational susceptibility of trees in high-quality neighborhoods can be explained if koalas also make foraging decisions at a larger ''patch'' scale resulting in a preference for ''good'' neighborhoods. Other studies have also shown that herbivores make simultaneous foraging decisions at multiple scales in experimental arenas (Hja¨lte´n et al 1993, Bergman et al 2005, but the success of this study in describing these processes in natural, continuous vegetation illustrates the value of this fine-scale mapping approach.…”

Roe deer (Capreolus capreolus L.) browsing effects and use of chestnut and Turkey oak coppiced areas

“…Additionally, roe deer were reported to feed highly selectively (Bergman et al 2005;Moser et al 2008;Jarni et al 2004). Given that the selection of browsing sites can be explained by differences in the food quality (Jarni et al 2004), the different taste of Turkey oak and chestnut sprouts could accordingly likely contribute to the observed browsing pattern.…”

Scenario analysis of planting density and pre-commercial thinning: will the mixed forest have a chance?

“…For instance, in Scandinavian forests aspen, pine and birch are more attractive to moose (Alces alces) than Norway spruce (Jalkanen 2001;Kullberg and Bergstrom 2001). However, not only specific preferences but also the surrounding landscape matrix will affect the probability of an individual seedling being browsed (Hornberg 2001;Edenius et al 2002;Bergman et al 2005). Browsing tends to be more intense in mixed species stands and, unsurprisingly, most severe in stands dominated by mixtures of attractive species (Vehviläinen and Koricheva 2006;Milligan and Koricheva 2013).…”