Local and seasonal variations of roe deer diet in relation to food resource availability in a Mediterranean environment

Abstract

Feeding behaviour patterns of European roe deer are well known but not in their southern range, where in contrast to Central and northern Europe the climate is characterised by mild winters, but hot and dry summer months. Spatial and temporal variations of the roe deer diet were investigated by analyses of 597 faecal samples in a coastal area in Italy. The aim was to evaluate the adaptive strategies of dietary intake to seasonal availability of different forage types in areas of fairly natural Mediterranean scrubwood and different areas dominated by agricultural habitats. A wide range of plant taxa (151 species/genera) was used, belonging to eight categories. A gradient was found from a diet dominated by woody plants and fruits in natural habitats to one characterised by cultivated plants in the agricultural areas. Usage of forage categories in areas dominated by woodland was proportional to their availability, whereas diet selection was found in the agricultural habitats, particularly marked in summer, the time at which food quantity and quality decreased due to harvest and drought. As to seasonal variation, the summer and autumn diets included more deciduous browse, whereas the winter diet was characterised by an increasing use of cereals and grass. In most areas, half-woody browse and fruit were preferred; grass and cereals were used less than expected by their availability. Most probably, selective behaviour patterns are linked to the difference of quality between plants together with their variable abundance, which is more evident in agricultural areas than in the woodland.

Seasonality, weather and climate affect home range size in roe deer across a wide latitudinal gradient within Europe

“…This also fits with the interpretation of reduced activity of animals at high temperature (Beier & McCullough 1990). The positive association between temperature and HR size in southern Italy, where plant productivity is mainly limited by summer temperature and water stress (Minder 2012), is also consistent with an effect of primary production. Overall, our results could support the prediction that species are limited at the northern edges of their range by abiotic conditions (e.g.…”

Dietary partitioning between European roe deer and European brown hare

“…It is commonly recognized as a browser, but it can exploit a large number of plant species, adapting its dietary niche to the spatiotemporal variation of food availability (e.g., Tixier and Duncan 1996;Duncan et al 1998;Wallach et al 2010;Minder 2012). In open and agricultural systems, the roe deer can become a grazer and it can feed largely on grass (e.g., Minder 2012).…”

“…Sixty-four fresh fecal samples/species were collected in the field (8 samples/species/season), in rectangular plots (4 × 20 m), randomly located in the habitats present in our study area (n = 20; Sangiuliano 2010). Samples were analyzed in the lab through micro-histological analyses (see Minder 2012;Lovari et al 2014). For each fecal sample, five pellets were ground in a mortar, washed with tap water through a 0.1 mm mesh sieve, clarified with household bleach (NaOCl <5 %), and washed again through the sieve.…”

“…Roe deer have been termed "concentrate selectors" (sensu Hofmann 1989), relying mainly on nutritious food items ). However, they are ecologically flexible and, especially in open and agricultural landscapes, they can behave as grazers, increasing their use of graminoids (Minder 2012). European brown hares exploit mainly spontaneous and cultivated herbaceous vegetation, relying especially on graminoids (e.g., Katona et al 2004;Reichlin et al 2006).…”

Influence of weather and phenotypic characteristics on pregnancy rates of female roe deer in central Italy

“…Early winter coincides with the last period of the embryonic diapause, which occurs in roe deer from August to December ; therefore, adverse weather conditions in this period are likely to limit female fecundity, increasing embryonic implantation failure (Hewison and Gaillard 2001). In contrast, Mediterranean winter months are characterized by mild conditions with abundant water supply, whereas summers are hot and dry, representing the harshest period of the year for ungulates owing to limited precipitation and reduced quantity and quality of food (Wallach et al 2007;Carvalho et al 2008;Minder 2012). Thus, rainfall can be expected to positively inluence food availability to females during lactation, weaning and rut, and consequently to increase the survival probability of fawns and the fecundity of females.…”