Seed dispersal by deer : Endozoochorous seed dispersal by roe deer (Capreolus capreolus), red deer (Cervus elaphus) and fallow deer (Dama dama) in a semi-natural landscape

This report discusses a study on endozoochorous seed dispersal by roe deer (Capreolus capreolus), red deer (Cervus elaphus) and fallow deer (Dama dama) in a semi-natural landscape. In three areas on the Veluwe samples are taken of three different parts of the digestive tract to determine seed survival rate and potential dispersal by deer. In two areas droppings are collected to determine number of viable seeds and species in dung. In total 10 plant species are present in droppings and rectum samples and can be dispersed. Deer species dispersed mainly common plant species. No significant differences are found between digestive stages and between deer species for number of viable seeds and plant species. Seed survival rate (rectum/rumen ratio) was the highest in roe and red deer (>600%) and the lowest in fallow deer (>200%). Species survival rate was highest in roe deer (100%) and lowest in fallow deer (28.6%). Fallow deer droppings contained significantly more seeds than red and roe deer droppings and significantly more plant species than roe deer droppings. Based on the results of this research roe deer seem most selective of the three deer species, because absolute number of seeds and plant species is lowest. Fallow deer seem least selective. Seed and plant species survival is the highest in roe deer, which suggests that roe deer are most inefficient digesters. Based on this study endozoochorous seed dispersal by deer seems of little importance for dispersal of plant species in a semi-natural landscape, because only a small range of common species (n=10) is germinating in rectum samples and droppings.