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Recent studies have shown that an increase in the population size of sika deer (Cervus nippon) decreases the abundance of rodents but increases that of several invertebrates (Scarabaeidae, Rhaphidophoridae, and earthworms) outside a deep-proof fence in Oku-Nikko, Japan. Therefore, the diet of red foxes (Vulpes vulpes) feeding on these animals is expected to vary according to changes in prey abundance. As red foxes also scavenge deer carcasses, an increase in the number of deer is expected to lead to changes in the red fox diet. In this study, the diet and sightings of red foxes inside and outside the fence were compared. Generalized linear mixed models indicate that the sika deer remains, ground-dwelling insects (Scarabaeidae and Rhaphidophoridae as a group, and Carabidae), and earthworms increased in the fox diet outside the fence, while the ingestion of voles decreased. The difference in prey consumption by red foxes was probably caused by differences in prey availability inside and outside the fence or the presence of available alternative food. These results suggest that red foxes demonstrate dietary plasticity in areas where habitat structure has been substantially modified by deer grazing. Although the abundance of voles, the primary food of red foxes, decreased outside the fence, the sighting rates of red foxes obtained by spotlight count were not significantly different between inside and outside the fence, suggesting that the presence of the others increased or available alternative food may have compensated for the negative effects of decreasing vole abundance.

It was thought by the author of the present study that if both automatic cameras and LARS were used, instead of one or the other, then it would be possible to efficiently gain knowledge that could be applied in the strategic management of deer in wetlands. In the Mizorogaike wetland, deer (Cervus nippon) graze plants throughout its entire area. Aerial images taken in the winter were used in the deer trail survey, as the vegetation would be withered, and the deer trails become easier to identify. The rare species selected to evaluate the effect of deer on vegetation was Menyanthes trifoliata, which was reported to be on the decline in the Mizorogaike wetland. The deer trails were identified visually. M. trifoliata was detected in the images using deep learning. I investigated the relationship between increases and decreases in areas covered by M. trifoliata during the period from 2016 to 2019 and the distance of these areas from deer trails. Three routes were selected where the deer trails indicated that the deer might be crossing the water. Four camera traps were set up on the land side facing the water. In the Mizorogaike wetland, during the period from 2015 to 2019, the area where deer trails could be observed spread to every corner of the wetland. Deer trails became conspicuous at the southwest edge of the Mizorogaike wetland. Although in 2015 the deer trails were limited to the northern half of the floating mat, by 2019, they had spread down into the southern half. Although camera traps were only used to investigate the wetland in 2019, it is thought that deer began to regularly swim across the water during the period from 2015 to 2019 and that this led to trails forming in the south of the floating mat. The area covered by M. trifoliata decreased by 20% from 2016 to 2019. The areas where M. trifoliata cover decreased tended to be nearer to deer trails than the areas where it increased.

At the landscape scale, localised culling is often conducted to achieve various deer management aims. However, few studies have assessed the effects of localised culling on deer population dynamics, owing to the spatially and temporally insufficient datasets of deer abundance that are derived from limited survey efforts. In this study, we estimated the population dynamics of a sika deer (Cervus nippon) population in the Tanzawa Mountains, central Japan, by Bayesian state-space modelling using spatiotemporally insufficient abundance indices and evaluated the effects of unit-specific culls on subsequent density changes in 56 units. The responses of deer density to unit-specific culls differed greatly among units, and a very weak correlation was observed between the intensities of unit-specific culls and the reduction in density. Deer populations in some units tended to resist density decreases despite high culling pressure, whereas those in other units were susceptible to density decreases with little to no culling pressure. Because the spatial scales of each unit were relatively small, annual density changes in each unit were largely influenced by deer movement in this estimation. The obscured effects of unit-specific culls, which were probably derived from deer movement among units in this case study, re-emphasized that deer migration should be incorporated into the planning of localised culling and that deer management should be coordinated over a wide area beyond landscape components and landownerships. Thus, we conclude that Bayesian state-space modelling is valuable for practical deer management programs at a large spatial scale even if different abundance indices are used.

A nickel (Ni)-plated copper-solid bullet type released up to 93 μg Ni /10 g bullet mass when immersed into meat juice for 7 days (to simulate fragments remaining in venison). A non-nickel-plated counterpart of identical construction released no Ni, but up to 250 μg copper. During thermal processing of pork cubes with embedded bullets, an average of 2.8 and up to 4.3 (maximum) μg Ni were released from the Ni-plated bullet to the surrounding meat. Average nickel and copper content in meat samples (taken in 2–3 cm distance from the shot wounds) from 30 roe deer (Capreolus capreolus) and 3 sika deer (Cervus nippon) killed with nickel-plated copper bullets did not differ significantly from those in controls (roe deer haunch). Contamination scenarios would Cu and Ni contents per portion increase moderately by 20 and 3.3 μg, respectively. In order to limit alimentary Ni uptake, the technological need for Ni-plating of bullets should be carefully evaluated.

The tick-transmitted Anaplasma phagocytophilum has been recorded in a range of mammal species and causes granulocytic ehrlichiosis in humans, horses, and companion animals as well as tick-borne fever in ruminants. Although deer and other ruminant species are known to be natural hosts, the distribution among sympatric deer populations is unexplored. Blood from 80 deer of four species were screened using an A. phagocytophilum-specific real-time polymerase chain reaction. Overall, 29% (19–40) of deer tested positive. Fallow deer (Dama dama), the most numerous species, had significantly lower prevalence (21%) than roe (Capreolus capreolus), red (Cervus elaphus), or sika (Cervus nippon) deer (average 50%). It is suggested that patterns of habitat use influence infection levels in different deer species. The role of deer as reservoirs of anaplasmosis remains unknown; however, prevalence in deer could be a useful index of local infection pressure and the risk of disease in domestic animals and humans.

To determine the geographical origin of the sika deer (Cervus nippon) naturalized in Germany and Austria, we sequenced the mitochondrial control region for 214 individuals. Adding these sequences to previously published data from native sika deer across its natural geographic range, the total comes to 245, extending what is already known about the geographical variation in this sequence in Cervus nippon. From these sequences, a neighbour-joining tree was constructed. This tree showed that the 49 different mitochondrial (mt)DNA types are grouped into three distinct phylogenetic clusters, which correspond to different geographic areas. Similarities between sequences of the naturalized sika deer and those described from native sika deer from both southern Honshu, Kyushu with associated islands, and northern Honshu suggest that the ancestors of the sika deer populations in Germany and Austria originated from the Japanese archipelago. In contrast, there is no evidence that female sika deer of Chinese, Taiwanese or north Vietnamese origin were involved in the ancestry of the present sika population in Germany and Austria.

The relationships among 214 wild-living sika deer from five locations in Germany and two in Lower Austria were examined using mitochondrial DNA (mtDNA) control region sequence. A total of 18 haplotypes are grouped consistently into two major divergent clades, A and B, which differ by a mean of 8.4% sequence divergence. Recently introduced sika deer showed a complex pattern of population structuring, which probably results from historical vicariance in at least two unknown source populations from southeastern Asia (as previously described by morphological and mtDNA findings), and subsequent population admixture as a result of human-mediated restocking. A strong genetic differentiation among populations was indicated by a global ΦST value of 0.78 reflecting mainly the differential distribution of clades A and B haplotypes. There was no association between related haplotypes and their distribution among local populations. These indicate that genealogy is a better predictor of the genetic affinity among most sika deer populations than their present-day locations. The abundant mitochondrial divergence we observed, may reflect a subspecies differentiation and could be associated with phenotypic differences among the introduced sika deer.

A case of pedicle and antler abnormality in a 12–14 year old sika stag shot in January 2003 in Schleswig-Holstein (Germany) is presented. The abnormality combines fusion of pedicles and antler bases with subsequent double-head formation. Double-heads result from growth of new antler bone without casting of the previous hard antlers. In consequence, two consecutively formed antlers are present in an individual. The stag’s skull showed a plate-like osseous structure whose broad and slightly elevated central portion was identified as the fused pedicles. The peripheral parts of this osseous plate constituted the second antler growth of the (former) double-head. A cast pair of antlers, which were fused at their bases, had been found in a neighbouring hunting district in the summer of 2002. The close fit between the casting surface of the fused antlers and the surface of the pedicle/antler structure on the stag’s skull indicated that the antlers had been grown by this stag and were belatedly cast from his fused pedicles. The fused antlers thus constituted the first antler growth of the double-head. We suppose that the broad connection between the fused antlers and the fused pedicles prevented antler casting at the normal time and thereby caused the double-head condition. The presentation of this antler abnormality is taken as an occasion to discuss the significance of pedicles for the normal casting and regeneration of antlers.