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.
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.
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.
The increase in wild boar numbers in recent decades is partly due to the involvement of most young females in reproduction as early as their first year of life. After the rut of adult females is over, young females are still entering oestrous as they attain maturity, prolonging the rutting period by several months. This study aimed to evaluate the effect of seasonality on the growth rate of male wild boar bodies, the growth of piglet and yearling male wild boar gonads, and sperm concentration in the epididymides. We found that yearlings’ weight and body length were almost constant in summer and autumn, with a sharp increase in winter. Seasonality was also reflected in the body condition index, which rose by more than 41% between summer and winter. In terms of seasonality, the testimetric dimensions again differed significantly only in winter. Sperm were recorded in piglets weighing more than 15 kg. Regardless of the time of capture, 41% of piglets were examined as juveniles, only 6%, resp. 8% of piglets reached low or medium concentration values. While 10% of all yearling males were azoospermatic (juvenile), regardless of weight, there was evidence of seasonality in the proportion of males with measurable concentrations. These concentrations gradually increased from 62.5% in summer to 78.6% in winter. No sterile male over two years of age was noted. The results show that even in wild boars, there is a culmination not only of physical characteristics in winter but also a culmination of testimetric dimensions. Sperm already occur in 15 kg of piglets, which means they can theoretically participate in the fertilisation of female piglets.