Cent. Eur. J. Biol. • 8(1) • 2013 • 8-17 DOI: 10.2478/s11535-012-0108-2 Central European Journal of Biology Autumn-winter diet overlap of fallow, red, and roe deer in forest ecosystems, Southern Poland Research Article Artur Obidziński1,*, Piotr Kiełtyk2, Jakub Borkowski3,4, Leszek Bolibok5, Karolina Remuszko3,6 1Department of Forest Botany, Warsaw University of Life Sciences, 02-776 Warsaw, Poland 2Faculty of Biology and Environmental Sciences, Cardinal Stefan Wyszyński University, 01-938 Warsaw, Poland 3Department of Forest Ecology, Forest Research Institute, 05-090 Sękocin Las, Poland 4Department of Forestry and Forest Ecology, University of Warmia and Mazury, 10-727 Olsztyn, Poland 5Department of Silviculture, Warsaw University of Life Sciences, 02-776 Warsaw, Poland 6Forest Directorate Wielbark, 12-160 Wielbark, Poland Received 30 May 2012; Accepted 21 September 2012 Abstract: The wild population of fallow deer in Central Europe has grown considerably over the last decade. However, information on feeding habits of this alien species in relation to the indigenous red deer or roe deer, in areas of their co-occurrence, is scarce. A prevailing view maintains that their food-niches are distinct, although direct comparative studies have not been carried out. Therefore, the aim of the research was to compare the diets of fallow, red, and roe deer feeding in the same habitat. Research was based on the rumen contents of 242 animals hunted in the autumn-winter season in the forests of Southern Poland. The analyses demonstrated that fallow deer are moderate grazers in such conditions and eat more graminoids in comparison to red or roe deer (36.4% vs. 16.1% or 5.5%, respectively). On the other hand, it feeds on less browse (17.2% vs. 41.4%) or dwarf shrubs (8.4% vs. 19.0%) than red deer, and on less bramble (10.9% vs. 34.6%) or forbs (4.0% vs. 7.6%) in comparison to roe deer (P=0.05). Although the diets of the three deer species differ in terms of the proportion of each food type in their diet, overlapping of their food-niches is high (52.6%). Keywords: Ungulates • Feeding preferences • Dama dama • Cervus elaphus • Capreolus capreolus • Central Europe © Versita Sp. z o.o. 1. Introduction and regulation due to their role in the environment [e.g. 9-11]. Ungulates transform inhabited ecosystems to a great Roe deer, Capreolus capreolus, and red deer, Cervus degree. They influence species composition and elaphus, are the most common cervids in Europe. Their structure of plant communities [1-3]. They also have an ecology is researched and presented in various studies indirect impact on populations of invertebrates, birds, [e.g. 12,13]. Fallow deer, Dama dama, have been and even small mammals [e.g. 4-6]. Therefore, the historically less common and less well-studied. This significant growth of the number of ungulates recorded in species was introduced in southern Europe from Asia Europe [7,8] requires adequate examination, monitoring, Minor in antiquity and is presently spreading intensely * E-mail: [email protected] 8 A. Obidziński et al. across Central Europe [14]. For example, the number of In response to the aforementioned factors, we fallow deer has risen in Poland nearly fourfold in the years focused our research on the study of the autumn-winter 2000–2010 – from approximately 6500 to 23300, in spite diet of fallow deer, in comparison with the diet of roe and of a simultaneous increase of the hunting harvest from red deer, in the forest environment of Central Europe. 1700 to 5100 specimens yearly (Central Statistical Office. The following hypotheses were formulated based on the Forestry 2010, http://www.stat.gov.pl/gus/5840_1540_ premises listed above: 1) graminoids constitute the main PLK_ HTML.htm, Last access 15.04.2012). component of fallow deer autumn-winter diet in central The growth of the fallow deer population in Europe Europe; 2) percentage share of particular food types in and its subsequent impact on the environment, the diet of fallow deer differs from that in the diets of roe especially on forests, has resulted in keen scientific or red deer, so the overlap is small; 3) the diet of fallow interest. Results of a number of studies suggest little deer is more opportunistic, so it is more varied than that impact of fallow deer on tree stands [e.g. 15-18]. while of roe or red deer. others demonstrate significant economic damage and unfavourable environmental changes [e.g. 19-23], including inhibition of the natural regeneration of stands 2. Experimental Procedures and changes in the direction of vegetation succession [e.g. 24,25]. Fallow deer most frequently feed on 2.1 Study area graminoids [15,17,26-32]. However, occasionally their The research was carried out in the Raciborskie Forest diet is dominated by tree browse [19,23,28,30], acorns over an area of ~40 000 ha situated in southern Poland: [15,16,33], dead leaves and lichens [34], or fruits [35]. N50º08’00”-23’10” and E18º11’50”-33’40”, at an altitude As fallow deer are an alien species in Central Europe, of 178–252 m above sea level (Figure 1). Arenosols it is of further value to establish whether there may be food prevail in the southern and western portions of the area. competition between fallow deer and indigenous cervids, They represent coniferous forest habitats with Querco and if so, to what extent. This is especially important roboris–Pinetum potential vegetation. Cambisols prevail considering observations that indicate that the growth in the north and east, and they represent broadleaved of the fallow deer population may cause a decrease in forest habitats with Galio–Carpinetum and Melico– the roe deer population [36,37]. Comparative studies Fagetum potential vegetation (Matuszkiewicz, J. M. of the diets of the above-mentioned cervids inhabiting 2008. “Potential natural vegetation of Poland – numeric the same areas simultaneously are scarce. They map”, IGiPZ PAN, Warszawa, http://www.igipz.pan.pl/ demonstrate that fallow deer eat less forbs or browse and more graminoids than roe deer [23,27], as well as KĘDZIERZYN- more graminoids, forbs, or acorn and less browse than KOŹLE red deer [28,32,38]. However, no comparative studies of all three – fallow, roe, and red deer – living in the same place at the same time have previously been published. Existing information on the fallow deer’s diet and its comparison with roe or red deer’s diets comes mostly from areas with mild winters [e.g. 15,16,19,28,33]. Odra River Snowy winters usually cause an increase in feeding on browse in all cervids [e.g. 28,39,40]. However, even seasonal differences in nutritional content in plants can cause alter the composition of the diet [41]. Long lasting snow cover, typical for the study area in Central Europe, N RUDY can cause different feeding behaviour in fallow deer from W E that described in the south and west of the continent. S It can be supposed that limited access to forest floor POLAND vegetation, due to a thick layer of snow, should result in 0 5 10km an increase of browse in the fallow deer’s diet, and more intense competition between the three cervids species research area multiaged managed forest for access to food supplies. Results of our study of the fallow deer’s diet can be of practical significance for main rivers even-aged thickets decision making on this species’ population size control in this part of the continent. Figure 1. Location of the study area. 9 Autumn-winter diet overlap of fallow, red, and roe deer in forest ecosystems, Southern Poland geoekoklimat/roslinnosc/prn_mapa/home_pl.htm. Last analysed. Material for analyses was collected during access 15.04.2012). The mean temperature is -1.2ºC the September–February hunting season from the years in January, and 18.1ºC in July. The mean annual 2004/5 to 2010/11. 242 rumina of hunted animals were precipitation level is approximately 630 mm and the used for the study. Collected material included 84 fallow vegetation period lasts about 224 days [42]. About deer, 93 red deer, and 65 roe deer. 127 specimens 9000 ha of the Raciborskie Forest stands were burnt were killed in autumn and 115 in winter. 86 samples in the year 1992. Over 6000 ha were replanted, mostly were obtained from large thickets and 157 samples with Scots pine. The remaining area regenerated on its were obtained from regular managed forest (Table 1). own, mainly with silver birch [43]. In the period of study, Samples were collected across the entire area of study regeneration reached the stage of thickets 11–18 years with a close to regular distribution. The distribution in age. of the sexes in each species sample was 37 males, Scots pine (Pinus sylvestris) dominates the forest as 37 females, and 10 calves in fallow deer; 36 males, a whole, occupying 68% of its area. Silver birch (Betula 38 females, and 19 calves in red deer; and 11 males, 48 pendula) occupies 13%, and pedunculate oak (Quercus females, and 6 fawns in roe deer. The lower number of robur) occupies 9%. Norway spruce (Picea abies), male specimens among the roe deer sample (caused by European beech (Fagus sylvatica), oak (Quercus robur), hunting laws in Poland) does not need to be considered, and black cherry (Prunus serotina) prevail in the shrub as differences between the diets of opposite sexes of layer of the unburnt parts of the forest. Common bracken roe deer are generally insignificant [e.g. 39,45,46]. The (Pteridium aquilinum), bilberry (Vaccinium myrtillus), ages of hunted specimens were determined by dentine reed grass (Calamagrostis epigeios), wavy hair grass layers, but was not always available as hunters did not (Deschampsia flexuosa), quaking grass sedge (Carex consistently described samples.