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Forest Environmental Conditions Shape Carcass Mass but Not Antler Investment of Red Deer Stags (Cervus elaphus L.)—Study from Western European Populations
Population stability depends on environmental conditions and their changes, as well as the availability of energy resources. Animals allocate their energy to maintenance, growth, reproduction, and energy storage; therefore, trade-offs are expected between life history traits. Access to abundant resources is expected to manifest itself in the investment of male individuals in sexually selected traits, such as carcass mass and antler size. The study aimed to analyze environmental climate conditions on the carcass and antler mass, as well as on antler form in red deer (Cervus elaphus L.) populations. We analyzed the carcasses and the antler masses and forms of 550 red deer stags from three populations in Central–Western Europe that differ in climate conditions that were hunter-harvested between the 2017 and 2021 hunting seasons. Our data indicated that carcass mass was shaped by the location of the population, stag age, precipitation, and temperature, as well as the number of frost days from January to the harvest date. Antler mass and antler investment depended on stag age but not climatic factors. Regular antler forms were more often observed in the harsh environmental conditions. Our observation confirms that resource trade-off is related to carcass mass of red deer.
Application of the tyraliera counting method to the large-scale inventory of red deer Cervus elaphus in the northern part of Western Pomerania, Poland
Game animal damage in the forests and fields of Central Europe, which dramatically increased at the turn of the 21st century, has undermined the reliability of the size of game population estimates. It is hypothesized that this problem can be attributed to errors in the assessment of animal density. This study conducted game inventories in a region characterized by a large ungulate population using a count method with drivers in line formation (direct counts in control plots). The size of the red deer population in the investigated area was estimated using generalized linear models assuming a negative binomial distribution based on the compound distribution (including the zero-inflated model). The mean red deer density in spring 2012 was 21.5 animals/km2 of forest. The number of red deer determined during this study is often higher that hunters indicated in annual game management plans. For the rational management of populations, it is therefore necessary to verify those estimates periodically, e.g. every five years. The statistical analysis of data from tyraliera method counts may show the actual population size during spring. Thus, it can be the basis for adequately planning hunting bags. Adjusting the population density to the carrying environmental capacity should make it possible to reduce the pressure of red deer on forests and agricultural land.
Red Fox (Vulpes vulpes) and Wolf (Canis lupus) as a Reservoir of Cryptosporidium spp. and Giardia intestinalis in Poland
Infections with zoonotic pathogens have received increasing attention in recent years, as reflected in the literature of both veterinary and human medicine. Cryptosporidium and Giardia are recognised as the principal causes of waterborne outbreaks worldwide, but there is still limited data on the role of wild carnivores, such as red foxes and wolves, as reservoir hosts and in disseminating these pathogens in the environment. The aim of the current project was to analyse the prevalence and abundance of Cryptosporidium and Giardia infections in foxes from seven voivodeships and in wolves from the Warmia-Masuria Voivodeship in Poland and to conduct a phylogenetic analysis of the detected parasites. For the detection of both parasites, we used the commercial immunofluorescent assay MeriFluor Cryptosporidium/Giardia. For Cryptosporidium detection we also applied modified Ziehl–Neelsen (ZN) staining of faecal smears and, following PCR amplification, sequenced the 18S rDNA locus. For Giardia detection, we sequenced the glutamate dehydrogenase (gdh) gene. In total, 117 and 69 faecal samples obtained from red foxes and wolves, respectively, were screened for the presence of Cryptoporidium/Giardia. In red foxes, prevalence was 38.5% and 15.4% for Cryptosporidium spp. and G. intestinalis, respectively. In wolves, the prevalence of Cryptosporidium spp. was 14.5%, and only one sample was Giardia-positive. Cryptosporidium canis, Cryptosporidium sp. vole genotype, C. baileyi and Cryptosporidium sp. were identified in red foxes, while C. canis and Cryptosporidium sp. were detected in wolves. Our results indicate that red foxes and grey wolves act as reservoir hosts of Cryptosporidium spp. and G. intestinalis in natural areas in Poland.