Wild boar is an autochthonous animal species of the Czech Republic that has significantly increased its population density in recent years. There are concerns that there is an associated negative impact upon agricultural crop production however, objective methods for sustainable management of wild boar, especially for estimation of its population density and intensity of regulation are still lacking. Wild boar differs markedly from the other free-living ungulates in its spatial activity and food selection, which limits applicability of the experiences and methods used for other species. Two methods of wild boar population censusing in a forest environment were tested in this study. The density of wild boar was evaluated in an area of 2256 ha, circumscribed by both natural and man-made barriers that restrict wild boar migration. Wild boar abundance was estimated using traditional snow-track counting and photo trapping data analysis. Both field methods were used in the winter season 2009-2010. Wild boar abundance as assessed by snow-track counting was 6.3 ind./km2 and by phototrapping 6.8 ind./km2. The results have revealed that if correctly performed, both of the tested methods are applicable to estimate wild boar abundance. Photo trapping seems to be more accurate; it requires special equipment and is time-consuming, however, it provides additional information on the structure of the population and requires less experience to undertake. Combination of several methods is advisable.
Density and distribution of red deer (Cervus elaphus L., 1758) and roe deer (Capreolus capreolus L., 1758) in relation to habitat structure and distribution of food sources was studied using simple faeces transects and monitoring plots during winter in a floodplain forest along the Morava River. Deer densities detected on monitoring plots and parallel simple faeces transects were comparable, so we used the faeces transects, thus enabling us to gather data from a larger part of study area. Densities of both species were relatively high (red and roe deer; 9.6 and 7.0 ind./km2 respectively). Red deer preferred forest stands with dense (60–80 %) cover and a diversified shrub layer (more than three tree species). Roe deer mainly used old stands of age 50–99 years with a high cover of canopy layer and conversely low cover of herb layer, dominated by bramble. A positive relationship between the distributions of both species was detected. Inter-specific spatial interference was not observed, despite their high densities in the study area.
The relationship between faecal nitrogen (FN), dietary nitrogen (DN) and dietary metabolizable energy (DE) was studied in two localities in the region of the Jeseníky Mts, Czech Republic, during four seasons. The content of nitrogen in plants significant for nutrition ranged between 0.99 and 3.86 g/kg of dry matter and DE was from 7.8 to 10.7 MJ/kg of dry matter. The DN/DE ratio in individual plant species ranged from 1:2.49 (stinging nettle) to 1:9.05 (rowan). The content of nitrogen in vegetation samples correlated with the content of DE in all four seasons (p < 0.01). In both the red and roe deer the diet contained more DN and DE during the vegetation season (spring to autumn) than in winter. The content of FN corresponded to the changes in diet quality and was positively correlated with DN and DE contents in all cases. On the basis of the correlations found between FN and diet quality we conclude that the use of FN for evaluation of diet quality in ungulates is possible, on the condition that we know the composition of their diet in the studied environment. However, it is unwise to compare different feeding specialists or individuals of one species living in different habitats with different diet composition.
Differences in weight, nitrogen content and diaminopimelic acid (DAPA) content between individual pellets within pellet groups were assessed in red-deer (Cervus elaphus) faeces. Mean pellet weight in winter varied between pellet groups in 82% of cases. A 10 pellet subsample movided a 100% likelihood of getting a representative sample whereas 5 pellet subsample a 99.75% likelihood. Between pellet variations in nitrogen content, within a pellet group were smaller and not greater than experimental error. However, DAPA content varied greatly within pellet groups.
Deer are an important limiting factor for the growth of broadleaved trees in the forests of temperate zones. Their influence on vegetation was extensively studied in various forest types; however, data from floodplain forest is missing. The aim of this study was to confirm following hypothesis: The regeneration of the young tree stands in floodplain forest under high deer density is impossible without intensive protection by forestry management. Our hypothesis was confirmed only partially. Thanks to high production, the floodplain forest ecosystem is able to compensate for the lost biomass, so the browsing does not prevent the growth of natural tree regeneration. On the other hand, trees from artificial plantations are much more attractive for deer, their browsing is much more intensive, mainly during winter and regeneration is not possible without fencing.
Altogether 701 adult barbel, Barbus barbus were captured by electrofishing and individually tagged to study their local displacement and movements in a stretch of the River Jihlava (Czech Republic). A total of 149 fish were recaptured and 105 of them (70.47 %) were considered as ”resident” because they were always recaptured in the same, relatively restricted (250 - 780 m) stream section, which always contained a pool and was demarcated naturally by riffles on both edges. The remaining 44 recaptured specimens (29.53 %) belonged to the “mobile” part of population, their movements encompassing two (or exceptionally more) adjacent stream sections and at maximum a distance of 1680 m downstream or 2020 m upstream. The proportion of mobile barbel, relatively low in smaller and middle size classes, increased in the largest size classes (451–550 mm of SL). A rather limited extent of movements also suggests a relatively small area of home range in the studied stretch, which nevertheless provides satisfactory resources and favourable conditions required by barbel over their entire life cycle. The extent of movements and corresponding proportion of mobile fish appear to be increasing with diminishing habitat patchiness. In the stretch of River Jihlava studied, with a rich patchy heterogenous habitat and well developed riffle-pool-raceway structure, each section (pool) can be considered as a more or less isolated spatial unit containing its own, and in a certain degree, isolated component of a metapopulation.
Norway spruce is a wide-spread food resource and its utilisable biomass exceeds the needs of herbivores. Needles seem to be a generally ignored food component in temperate forests that is consumed only when there are no better food sources. It is used especially during winters with deep snow cover. The aim of this study was to test presumption of needles as nutritive poor component of ungulate diets through botanical diet analyses and chemical nutrition estimation (content of crude protein and metabolizable energy volume in faeces) and elaborate the calibration curve on indirect estimation of quality food resources for ungulates in environment (NIRS needle content in faeces). High content of spruce needles corresponded well with a low quality winter diet of wild ungulates and may reflect animal nutritional constraints. As a consequence, the content of spruce needles may be used as an easy index of animal performance in a particular environment in forested area with coniferous forests in temperate zone. Needle content can be determined from the faeces by near infrared spectrophotometer and this easy technique can be recommended as indicator of the food resources quality for ungulates.
An experiment was conducted to monitor the effect of the length of environmental exposure of faeces on the content of nitrogen and diaminopimelic acid. We used samples of the droppings of wild red deer and examined them for the content of N and DAPA upon exposure to field conditions for 0–7 days during the growing season and for 0–30 days in winter, and after a year of storage in dried and frozen state. In relation to nitrogen level, there were no differences between the samples of fresh droppings and those after different lengths of exposure to ambient conditions before analysis and no differences between fresh and stored samples. As to DAPA level, there were no differences between the samples of fresh droppings and those after exposure. Nitrogen and DAPA levels in the droppings were stable and can be measured in both fresh samples and samples that have been exposed to ambient conditions for one week in summer or one month in winter.
White-tailed deer were introduced into the Czech Republic about one hundred years ago. Population numbers have remained stable at low density despite almost no harvesting. This differs from other introductions of this species in Europe. We presumed that one of the possible factors preventing expansion of the white-tailed deer population is lack of high-quality food components in an area overpopulated by sympatric roe, fallow and red deer. We analyzed the WTD winter diet and diets of the other deer species to get information on their feeding strategy during a critical period of a year. We focused primarily on conifer needle consumption, a generally accepted indicator of starvation and on bramble leaves as an indicator of high-quality items. We tested the following hypotheses: (1) If the environment has a limited food supply, the poorest competitors of the four deer species will have the highest proportion of conifer needles in the diet ; (2) the deer will overlap in trophic niches and will share limited nutritious resource (bramble). White-tailed, roe, fallow, and red deer diets were investigated by microscopic analysis of plant remains in their faeces. The volume of bramble decreased in the diet of all four deer species from November to March. The content of conifer needles in the diet of white-tailed and roe deer was negatively correlated with bramble and in spring made up 90 % of their diet volume. On the other hand conifer needles in the diet of red and fallow deer occurred only in January with snow cover. Fallow and red deer started the compensation of winter starvation at least one monthearlier than both roe and white-tailed deer. a high content of conifers in white-tailed deer diet in the second half of the winter fully support the presumption about low nutritional food supply and its diet. It can lead to a markedly impaired condition for white-tailed and roe deer and negatively affect their condition. The dietary overlap of four sympatric deer species was extensive in winter. All species share a limited good quality food supply (bramble) when food is scarce, suggesting that interspecific competition may occur.