Influence of fawning on the spatial behaviour and habitat selection of female fallow deer (Dama dama) during late pregnancy and early lactation


Marco Apollonio, Dipartimento di Zoologia ed Antropologia Biologica, Università degli Studi di Sassari, Via Muroni 25, I-07100 Sassari, Italy
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Home-range sizes and habitat selection among calving and non-calving female fallow deer Dama dama were analysed during the last months of pregnancy and following parturition. The study was carried out in central Italy using radio-tracking techniques. It was based on data collected on 23 adult females (calving n=15, non-calving n=8) from March 2003 to August 2003. Seasonal and bimonthly home-range analyses showed marked differential spatial behaviour between calving and non-calving females only when fawns were present. These were born during June, and the summer and July–August home ranges of calving females were significantly lower than those recorded for non-calving ones. Although differences between spatial use of calving and non-calving females became significant only after the birth of fawns, habitat choices were significantly different from late pregnancy, when females had already reached parturition sites. Therefore, whereas during March–April calving and non-calving females showed similar habitat choices, from May, habitat selection proved to be significantly different between the two classes of females. In particular, major differences were detected in the use of marshes and meadows. That female fallow deer adopt anti-predator tactics during the calving season was shown by their higher use of marshes, the habitat that offers the greatest cover and provides good concealment for fawns. Calving females avoided meadows, because these are open areas without any concealment for fawns; however they were selected by non-calving females as a function of their high productivity, as shown by analysis of the grass quality of the study site. The use of sub-optimal habitats by calving females because of the presence of fawns confirmed the findings of previous studies. These showed that ungulate mothers may move to poorer but safer habitats, compromising their energy intakes, to reduce the predation risk to their neonates.