A record of acorn eating by sika deer in western Japan

The rumen contents of 14 sika deer (Cervus nippon) collected in November 1996 in Yamaguchi Prefecture, the western end of Honshu, Japan, were analyzed by the point-frame method. The contents were composed of high-quality foods like deciduous and evergreen browse and acorns. The composition, which consisted of a significant amount of acorns (27.8 ± 22.5%, mean ± SD), was in contrast to that of northern sika deer populations which exclusively eat graminoid leaves including dwarf bamboos. This is the first record of acorns being a major contributor to diet for wild sika deer. By the point-frame method, acorns were underestimated, and the weight contribution was much greater.     

Food habits of sika deer and nutritional value of sika deer diets in eastern Hokkaido, Japan

Rumen content analysis and field observations were used to investigate the food habits and diet quality of sika deer (Cervus nippon yesoensis Heude) from 1991 to 1993 in eastern Hokkaido, Japan. Diets varied seasonally, with deer consuming graminoids and browse in winter, forbs and agricultural crops in spring and summer and all of these plant foods in autumn. Eighty-four plant species with sika deer bite marks were identified and their use also varied seasonally. The diversity of food resources available provided both critical protein and digestible energy, allowing for physiological maintenance and seasonal growth. With these high-quality diets, deer maintained good body condition in eastern Hokkaido, where the population density was relatively low.     

Higher mortality of smaller sika deer fawns

Bodyweight, breast girth and hind-foot length were compared in sika deer fawns (Cervus nippon Temminck) that were shot or had died naturally. The study site was Mount Goyo, in northern Japan. Samples were collected in January and February every year from 1982 to 1991 for the dead fawns and from 1990 to 1992 for the living fawns. The average bodyweight and the variation in bodyweight was significantly smaller in the dead fawns than in the living ones, suggesting a higher mortality rate in smaller fawns. The mean breast girth and hind-foot length were also significantly smaller in the dead fawns. Two possibilities are suggested: (i) the smaller fawns were born later than the larger fawns and grew at normal rates; or (ii) the smaller and larger fawns were born in a similar period but grew at different rates thereafter.     

Summer dietary compositions of sika deer on Yakushima Island,southern Japan

Summer food habits of Sika deer (Cervus nippon yakushimae) on Yakushima Island, southern Japan, were studied focusing in particular onPseudosasa owatarii, a dwarf bamboo native to the island. Fecal analyses showed that the food habit of the Sika deer on Yakushima island was plastic: the dietary composition was dominated by graminoids (ca. 90%), particularlyP. owatarii (50%–60%) in the bamboo grassland of theP. owatarii zone above the timber line, whereas leaves and non-leafy parts of woody plants were important in the crytomeria forest and evergreen broad-leaved forest below the timber line. The maximum culm age ofP. owatarii was 8.5 yr, but the majority of leaves (97.8%) were younger than 2.5 yr. Since the weight contribution of the leaves is great (27.7%) and the turnover rate is high, theP. owatarii grassland affords a good foraging place for the Sika deer on Yakushima Island.     

Comparative rumen morphology of sympatric sika deer (Cervus nippon) and red deer (C. elaphus scoticus) in the Ahimanawa and Kaweka Ranges,central North Island,New Zealand

Eighteen sika deer (Cervus nippon) and 14 red deer (C. elaphus scoticus) were sampled from two areas where these closely related species are sympatric. Total body weight, carcass weight, age class, sex, and internal parameters (e.g. liver weight, kidney weight, rumen volume) were recorded. Samples of rumen wall mucosa taken from the dorsal rumen wall, atrium ruminis, caudoventral blindsac, and ventral rumen wall were used to compare rumen morphology between the two species (and also any area, sex, and age effects). Sika deer had significantly lower papilla densities in three of the four rumen wall sites and significantly smaller papillae than red deer in two of the four sites. Surface enlargement factors (SEFs) were calculated to provide comparisons of the effective absorptive surface within the rumens of the two species. The mean SEF for sika deer (4.76) was significantly less that for red deer (6.77), which suggests a greater degree of adaptation to digesting fibrous forage. In the central North Island, New Zealand, where the habitat has been considerably modified by introduced herbivores over the last century and food resources are depleted, such an adaptation would confer a competitive advantage on sika deer over red deer. It is postulated that this diet-related difference largely accounts for the ongoing replacement of red deer by sika deer where these two species are sympatric.     

Population density and group composition of Japanese sika deer (<Emphasis Type="Italic">Cervus nippon yakushimae</Emphasis>) in an evergreen broad-leaved forest in Yakushima,southern Japan

The population density of Japanese sika deer (Cervus nippon yakushimae Kuroda and Okada) in an evergreen broad-leaved forest in Yakushima, southern Japan, was surveyed over 4years from 1998 to 2001. Two approximately 50ha study sites, Hanyama and Kawahara, were established with a total of 4km of census trails at each site. The estimated densities of sika deer at the two sites were 43–70 deerkm^–2 at Hanyama and 63–78 deerkm^–2 at Kawahara, although these values might be underestimates. The adult sex ratio (number of adult males:number of adult females) ranged from 0.6 to 1.0 at Hanyama, and from 0.4 to 0.9 at Kawahara. Mean group size was 1.9 deer (male group, 1.5 deer; female group, 1.6 deer; mixed group, 3.6 deer). The population density of sika deer was relatively high compared to other sites in Japan, with the exception of very small (<10km²) islands. Possible explanations for this naturally high density of sika deer in an evergreen broad-leaved forest in Yakushima are discussed.     

Use of mires and food habits of sika deer in the Oze Area,central Japan

Sika deer Cervus nippon entered the Oze Area, a snowy area in central Japan, in the 1990s. The use of mires and the food habits of this species were studied in 1999 and 2000. Deer used the mires immediately after snow melted and did not use the mires in mid summer, although they did use them lightly in autumn. The summer food habits differed from those of the deer population living in Nikko in the lower area: non-Sasa graminoids and other monocotyledonous leaves occupied more (approximately 30%) of the feces in the former population, whereas Sasa nipponica, a dwarf bamboo, was the dominant food (60%) of the latter population. Seasonal changes in fecal composition in the Oze deer were that mire graminoids occupied a considerable portion of their food in spring (11.6%) and summer (17.0%), whereas the amount of dwarf bamboo increased in fall (26.0%). Despite the small size of the mires, Oze deer appear to prefer mires to forests. Nitrogen concentrations of the mire plants did not differ from those of the forest plants; however, foraging efficiency would be greater in the mires and this may explain the preference observed. Despite the small total biomass, leaf biomass of the mire was equivalent to that of the adjacent forest floor. In addition, biomass was concentrated near the ground, or the biomass concentration was greater than that of the forest floor.     

Survival and cause-specific mortality rates of female sika deer in eastern Hokkaido, Japan

Survival and cause-specific mortality rates of female sika deer (Cervus nippon) were studied using radio telemetry in eastern Hokkaido, Japan. We captured and radio-collared 18 female deer, and monitored their survival from April 1993 to May 1996. Estimated annual survival rate for adult females was 0.779 (95% confidence interval was 0.609–0.997). The harvest mortality rate of adult females was higher than the natural mortality rate. Experimental female hunting during 1994–1996 contributed to an increase in the mortality rate for females and was useful in the control of the sika deer population.     

Seasonal migration patterns of female sika deer in eastern Hokkaido,Japan

Fifty-seven female sika deer (Cervus nippon yesoensis), captured at the wintering area in the Shiranuka Hills in eastern Hokkaido, Japan, were radio-tracked during 1997–2001 to examine the factors affecting seasonal migration at the individual-landscape level. Ten of the 57 deers migrated between low-altitude summer home ranges and intermediate-altitude winter home ranges (the upward migrants). Twenty-nine migrated between high-altitude summer home ranges and intermediate-altitude winter home ranges (the downward migrants). Twelve used the intermediate-altitude home ranges all year round (the non-migrants). The remaining six were unknown. The summer home ranges of deer were widely scattered over an area of 5734km². Migration distances ranged between 7.2 and 101.7km. Deer showed high site fidelities to their seasonal home ranges. The upward migrants wintered in areas of less snow, higher quality of bamboo grass, and more coniferous cover than their summer home ranges. The downward migrants wintered in areas of less snow, higher quality of bamboo grass, higher winter temperature, and more southern slopes, but less coniferous cover than their summer home ranges. The non-migrants used year-round ranges with little snow, high quality of bamboo grass, and sufficient coniferous cover. We suggest that snow cover and bamboo grass are the factors affecting seasonal migration of the population and that coniferous cover is another factor for the upward migration.     

Characteristics of Sasa nipponica grassland as a summer forage resource for sika deer on Mt Ohdaigahara, central Japan

Recently, the sika deer, Cervus nippon Temminck, population has increased on Mt Ohdaigahara, central Japan. The dwarf bamboo, Sasa nipponica Makino et Shibata, is a primary forage plant for sika deer in this area. To demonstrate the characteristics of S. nipponica grassland, especially as summer forage for sika deer, the habitat use intensity of sika deer was estimated by fecal densities, and biomass, growth rate, removal by deer and crude protein content were examined. Sika deer utilized the S.nipponica grassland on Mt Ohdaigahara during summer when the biomass, growth rate and crude protein content of S. nipponica were high. The recent increase in the deer population seems to be partly due to S.nipponica grassland being a favorable summer habitat.     

Summer forage biomass and the importance of litterfall for a high-density sika deer population

The biomass of summer forage and their contributions were surveyed to show that litterfall supported a high-density population of sika deer (Cervus nippon Temminck) in summer on Nakanoshima Island, Toya Lake, Japan. In July 1974, the grassland had the highest productivity among understory vegetations (228±55kgha^–1: mean±SE). In deciduous forests, palatable plants occupied only 0.1% of the biomass of 0.872±0.366kgha^–1, and deciduous leaves within the reach of deer (=220cm at height) produced 0.208±0.070kgha^–1. However, litterfall during this period had the highest productivity, 28.7± 5.3kgha^–1. The deer consumed litterfall (75.6% in dry weight), short grasses (17.2%), deciduous forest understory (4.1%), deciduous leaves within the reach of deer (3.0%) and conifer plantation under story (0.1%). It is suggested that the high-density deer population would be maintained by litterfall through the year instead of browsing in deciduous forests, which has been overlooked.     

Fallen leaves and unpalatable plants as alternative foods for sika deer under food limitation

Feeding behavior and rumen contents of sika deer (Cervus nippon Temminck) under food limitation were studied on Nakanoshima Island, Hokkaido. During the phase of population growth, the deer subsisted on tree bark and twigs, deciduous leaves and dwarf bamboos (Sasa spp.) in the winter. After a crash in population, the deer began feeding on the fallen leaves of deciduous trees and continued to do so throughout the year. They also ate unpalatable plants Cephalotaxus harringtonia var. nana Rehd., Senecio cannabifolius Less. and Cynanchum caudatum Maxim. as winter foods, which used to remain untouched by deer, and had accordingly expanded their distributions, following a decrease in the amount of dwarf bamboos available. These facts suggest that sika deer drastically shift their foods and exploit alternative foods under conditions of food limitation.     

Tracing the genetic roots of the sika deer Cervus nippon naturalized in Germany and Austria

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.     

Edge effects created by clear-cutting on habitat use by sika deer on Mt. Goyo,northern Honshu,Japan

Clear-cutting increased the species diversity and amount of undergrowth plants in a habitat of Sika deer (Cervus nippon) on Mt. Goyo, northern Japan. The number of species increased from 15 to 48 as a result of clear-cutting. Among the plants,Sasa nipponica (a dwarf bamboo), an important forage plant for Sika deer, was predominant. Fecal pellets of deer were abundant in the forest and at the “adjacent zone” (from the edge to 150 m out of the forest) and thereafter decreased suddenly. The intensity of utilization ofSasa nipponica was also heavy in the forest, moderate at the adjacent zone and light 200 m from the forest edge. Since the amount of the bamboo in the forest was small, the removal of bamboo was greatest at the adjacent zone. Clear-cutting creates a favorable feeding area for Sika deer in this zone by increasing the available plant production and securing forest cover.     

A genetic study of sika (Cervus nippon) in the New Forest and in the Purbeck region, southern England: is there evidence of recent or past hybridization with red deer (Cervus elaphus)?

Sika Cervus nippon are native to Japan and East Asia but are now naturalized in many parks of the world, including Britain. In contrast to the substantial body of research on the extent of hybridization between sika and red deer Cervus elaphus in Scottish populations, there has been little genetic analysis of the English populations of sika. Sika in England still have a patchy and discontinuous distribution; populations are thus still genetically isolated and may be expected to show higher variability in genetic type. The current paper uses DNA-based techniques to explore the genetic composition of sika in the New Forest (Hampshire) and that of sika from the largest population in England, in the Purbeck region (Dorset). The study aims were to determine whether New Forest sika show signs of recent interbreeding with New Forest red deer populations, whether New Forest sika are genetically distinct from Purbeck sika, and whether New Forest and Purbeck sika show evidence of past hybridization or whether they are pure (non-hybrid) strains. Microsatellite analysis was used to compare the genetic profiles of individual deer. Results showed that sika and red deer in the New Forest were genetically distinct, indicating that there is no large-scale in situ hybridization occurring between these feral populations. In terms of overall genetic composition, there was no significant difference between the sika in the New Forest and Purbeck. However, a more detailed analysis found that New Forest sika showed a lower level of introgression with red deer compared with the Purbeck sika. We conclude that, overall, the New Forest sika deer do appear to be more genetically pure bred than the Purbeck sika.     

Daily rhythm and seasonal pattern of lick use in sika deer (Cervus nippon) in China

Many ungulates are reported to use natural or artificial licks with seasonal patterns around the world. From December 2016 to August 2017, we used infrared camera to record the use of artificial licks in wild sika deer (Cervus nippon) in Zhejiang Qingliangfeng National Nature Reserve, China. We explored the daily rhythm, seasonal pattern and sex difference in lick utilization. In total, 12,043 videos and 22,901 pictures were collected. Our results showed that: (1) the lick visiting frequency was higher at night than that during daytime; (2) the difference in lick visiting frequency between females and males disappeared after taking into account of sex ratio; (3) the lick duration peaked in April during a year. These findings suggested that there were clear daily rhythm and seasonal pattern of lick use in sika deer. Seasonal change in lick use intensity was consistent with our prediction. These variations in lick use might be driven by both the physiological needs of the mineral elements in different life stages and the seasonal changes in climate and food. The reserve management authority should pay more attention to the supplement of licks in spring and summer to fulfill animal’s physiological needs.     

Population genetic structure and the effect of founder events on the genetic variability of introduced sika deer, Cervus nippon, 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 _ST 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.An erratum to this article can be found at     

Food habits of sika deer on the Boso Peninsula,central japan

The rumen contents of sika deer (Cervus nippon Temminck) on the Boso Peninsula, central Japan, were analyzed to identify local, sexual and age-specific differences in food habits. Graminoids and woody plants were the primary foods throughout the year. In winter, the use of evergreen broad leaves increased. The food habits of sika deer on Boso Peninsula were intermediate between those of populations inhabiting northern and southern Japan. Acorns, mainlyLithocarpus edulis Nakai, were consumed in fall and winter with a peak in October. Since the availability of acorns is not influenced by foraging in previous years, it can be regarded as a stable food supply and hence may be important for deer on the Boso Peninsula. The local difference between the Amatsukominato (AT) area, having a large plantation ofLithocarpus producing acrons, and the Kamogawa-Katsuura (KK) area, having a small plantation ofLithocarpus, was recognized; seeds and fruit were consumed more in AT than in KK in fall and winter. Males consumed more seeds and fruit than females at both sites in fall. This can be attributed to sexual differences in nutritional requirement.     

Seasonal food habits of a sika deer population in the warm temperate forest of the westernmost part of Honshu, Japan

The rumen contents of 63 sika deer (Cervus nippon Temminck) shot in the westernmost part of Honshu were analyzed by the point-frame method. The rumen contents were dominated by forbs and the majority of these were evergreen monocotyledonous plants, probably Ophiopogon spp. Evergreen browse leaves (woody leaves), such as Eurya japonica Thunb., Ilex crenata Thunb. and Trachelospermum asiaticum Nakai, were also important, constituting 20–40% of the rumen contents. Other categories accounted for only small proportions, although in summer, graminoids increased but twigs and bark decreased in importance and in fall and winter, fruits and seeds increased in importance. The diet of the deer was characterized by high-quality foods even in winter and by a stability or less-pronounced seasonality throughout the year than found in the northern deer. These results were compared with those from other populations, including a northern sika deer population in Japan.