Kidney fat and marrow fat indices of the sika deer population at Mount Goyo, northern Japan

Fat deposits are effective indicators of the nutritional status of wild populations of ungulates. Three fat indices (kidney fat, femur marrow fat and mandible marrow fat) of sika deer (Cervus nippon) at Mount Goyo, northern Japan, were compared. The kidney fat index (KFI) was suitable for good and intermediate nutritional status, but could not precisely reflect poor conditions. Bone marrow fat indices (MFI) were not good indicators because samples with high MFI values did not distinguish between samples whose KFI values were different, and samples collected in non-winter seasons did not cover the range of poor conditions. It is therefore recommended to use both the KFI and the femur-MFI complementarily.     

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.     

Bottleneck effects on the sika deer Cervus nippon population in Hokkaido, revealed by ancient DNA analysis

The population size of the sika deer Cervus nippon on Hokkaido Island of Japan had been remarkably reduced because of heavy hunting pressure since the beginning of Meiji Period and effects of heavy snow in 1879 and 1881. After that, the number of sika deer in Hokkaido has increased gradually due to the protection by the Hokkaido government. In the present study, in order to investigate the bottleneck effects, we analyzed ancient mitochondrial DNA (mtDNA) on sika deer bones excavated from archaeological sites just before Meiji Period. On 86 of 113 bones from 13 archaeological sites of Ainu Culture Period (17-19th centuries), 602 base-pair fragments of the mtDNA control region were successfully sequenced. Consequently, we found three new haplotypes (g-, h- and i-types) which had not been identified in modern sika deer. In addition, four haplotypes (a-, b-, c- and d-types) identified from modern sika deer were also found in the archaeological deer. The new haplotypes and previously reported hapoltypes from sika deer of Hokkaido were phylogenetically much closer to each other, compared with those of modern sika deer from Honshu, Kyushu and the Chinese continent. Geographical distribution patterns of haplotypes of the ancient population were different from those of the modern population in Hokkaido. Our findings indicated that their genetic diversity was reduced through the bottleneck and that population structures of sika deer were changed widely in Hokkaido due to genetic drift.     

Variation in the herd composition counts of sika deer

Herd composition counts (HCC) are commonly used to assess population status in deer. We evaluated the reliability of HCC of sika deer (Cervus nippon Temminck) using repeated counts and by comparing estimated sex ratios and calf-to-female ratios of marked deer on Nakanoshima Island, Hokkaido, Japan between April 1999 and October 2000. Although both total counts and sex and age ratios fluctuated greatly by month, seasonal changes showed a relatively small variance. This suggested that seasonal changes in behavior within sex and age classes contributed to biased ratio estimates obtained from HCC. Route counts should be used as a relative population abundance index with estimates of detection probability, especially for females. Adult sex ratios and age ratios from HCC were unbiased during the rutting season (October–November), and age ratios in spring could be used if yearlings are counted as adults.     

Seroprevalence of fasciolosis in Hokkaido sika deer (Cervus nippon yesoensis) from Hokkaido Prefecture,Japan revealed by ELISA using recombinant cathepsin L1

Fasciolosis, a zoonotic disease caused by liver flukes of the genus Fasciola, has been reported in Hokkaido (Yezo) sika deer (Cervus nippon yesoensis) in Hokkaido Prefecture, Japan; however, the actual seroprevalence in the animal has not been adequately evaluated. The objective of the present study was to analyze the seroprevalence of the disease among Hokkaido sika deer. Recombinant cathepsin L1 (rCatL1) was used as an antigen for an indirect enzyme-linked immunosorbent assay (ELISA) to detect antibodies against Fasciola flukes. The sensitivity and specificity of the ELISA were 84.6% and 100%, respectively. The average seroprevalence in 1109 Hokkaido sika deer from 20 locations in Hokkaido Prefecture was 43.9%. Mature deer showed higher seroprevalence than younger individuals; however, even younger animals may act as a reservoir for the disease. Monitoring infection levels in the Hokkaido sika deer population is important not only for the livestock industry, but also for preventing human fasciolosis.     

A reliable body condition scoring technique for estimating condition in African buffalo

Evaluating animal body condition is a necessary component of many ecological studies. Although many methods for assessing animal body condition have been developed, relatively few can be used for estimating condition on live animals. Noninvasive body condition scoring techniques have been developed for assessing condition in livestock and more recently such techniques have been applied to wild ungulates. In this study, we examined the reliability of a body condition scoring technique for assessing condition in African buffalo (Syncerus caffer caffer). We compared a body condition score (BCS) based on visual assessment and manual palpation of an animal’s body to two standard metrics of condition widely used in mammals: kidney fat index (KFI) and haematocrit (HCT). Across all buffalo, BCS was significantly and positively correlated with both KFI and HCT. For HCT, this pattern was observed among adults, juveniles, males and females; and in the wet season but not in the dry season. For KFI, BCS was significantly and positively correlated with KFI among adults, juveniles and males, but not in females. Overall, our results suggest that the BCS technique can serve as a useful method for estimating body condition in buffalo.     

Food habits of sika deer in the Shiranuka Hills,eastern Hokkaido: a northern example from the north–south variations in food habits in sika deer

Seasonal changes in the composition of the diet of the sika deer population in the Shiranuka Hills, eastern Hokkaido, in 1998 were determined by fecal analyses. The deer were dependent on Sasa nipponica, a dwarf bamboo, throughout the year, particularly in winter when it accounted for as much as 77.7% of the diet. It accounted for 33.1% and 45.6% in spring and summer, respectively, and this decreased to 12.2% in autumn. Besides S. nipponica, all the graminoid categories accounted for large amounts (66–96.7%), while dicotyledonous plants accounted for little (3–8%) except in autumn when they accounted for 31%. The strong dependence of the Shiranuka population on graminoids was different from other Hokkaido deer populations, for example the population from Ashoro/Onbetsu and the extremely high density population on Nakanoshima Island. In spite of these differences, food for all Hokkaido sika deer was poor in winter. Along the north–south geographical cline in the food composition of sika deer along the Japanese archipelago, the Shiranuka population was positioned as a grazer type, in contrast to the southern populations. However, it is important to note that variations are great among local populations in Hokkaido.     

Condition and related mortality of nyala Tragelaphus angasi in Zululand, South Africa

The kidney fat index (KFI) was used to examine the condition of nyala over a 27-m-onth period. From a sample in which both marrow fat and KFI were examined, it was noted that, as has been found in other bovid, kidney fat was mobilized before marrow fat. Seasonal changes in condition were observed and correlated with the rainfall in the previous month. Following periods of less than 50 mm of rain, the larger adult males were in significantly poorer condition than other animals.
The sexual difference in condition is attributed to the differences in body size, where males of asymptotic body mass required 62% more kcal/day than asymptotic mass females. When die-offs occurred during periods of nutritional stress, significantly more old adults died than would be expected. Further, significantly more males died than females.     

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.     

Adaptive management of sika deer populations in Hokkaido, Japan: theory and practice

We investigated the utility of adaptive management (AM) in wildlife management, reviewing our experiences in applying AM to overabundant sika deer (Cervus nippon) populations in Hokkaido, Japan. The management goals of our program were: (1) to maintain the population at moderate density levels preventing population irruption, (2) to reduce damage to crops and forests, and (3) to sustain a moderate yield of hunting without endangering the population. Because of significant uncertainty in biological and environmental parameters, we designed a “feedback” management program based on controlling hunting pressure. Three threshold levels of relative population size and four levels of hunting pressure were configured, with a choice of four corresponding management actions. Under this program, the Hokkaido Government has been promoting aggressive female culling to reduce the sika deer population since 1998. We devised a harvest-based estimation for population size using relative population size and the number of deer harvested, and found that the 1993 population size (originally estimated by extrapolation of aerial surveys) had been underestimated. To reduce observation errors, a harvest-based Bayesian estimation was developed and the 1993 population estimate was again revised. Analyses of population trends and harvest data demonstrate that hunting is an important large-scale experiment to obtain reliable estimation of population size. A serious side effect of hunting on sika deer was inadvertent lead poisoning of large birds of prey. The prohibition of the use of lead bullets by the Hokkaido Government was successful in reducing the lead poisoning, but the problem still remains. Two case studies on sika population irruption show that the densities set by maximum sustainable yield may be too high to prevent damage to agriculture, forestry, and/or ecosystems. Threshold management based on feedback control is better for ecosystem management. Since volunteer hunters favor higher hunting efficiency in resource management (e.g., venison), it is necessary to support the development of professional hunters for culling operations for ecosystem management, where lower densities of deer should be set for target areas. Hunting as resource management and culling for ecosystem management should be synergistically combined under AM.     

Functional dietary response of Asian black bears to changes in sika deer density

Omnivores are generally opportunistic foragers and have a flexible dietary response to resource abundance and availability. Their populations may consist of individuals that differ from each other in terms of their trophic positions, which implies that the dietary response to resource fluctuations differs within a population. We investigated how changes in the abundance of sika deer (Cervus nippon) affected dietary variation and body condition in the Asian black bear (Ursus thibetanus). We used fecal analysis, nitrogen stable isotopes (δ¹⁵N), and body measurements to determine whether the variation in dietary meat content of Asian black bears is positively related to variations in the density of the sika deer population, whether male bears have a higher trophic position compared to females, and whether dietary meat content is positively related with body mass or body condition of bears. We found a positive correlation between the occurrence of deer remains in bear feces and deer density, suggesting that bears change their diet in response to temporal changes in deer density. Male bears had higher δ¹⁵N values than females, and neither values varied when deer density decreased. Males selectively consumed deer after a reduction in deer density, whereas females consistently consumed more plant-based diet. The δ¹⁵N values were positively related with body mass of adult (>4 yr) bears but had no relationship with body condition of bears of either sex or any age class. Deer seem to be an important food source for large adult males, which have an advantage in mating. Thus, increasing herbivore abundance and availability altered the foraging strategy of Asian black bears, but the importance of herbivore on bear diet differs within a population.     

Borrelia burgdorferi Sensu Lato in an Endemic Environment: Wild Sika Deer (Cervus nippon yesoensis) with Infected Ticks and Antibodies

Ticks and blood samples were collected from wild sika deer (Cervus nippon yesoensis) during a hunting season (August to October) of 1991 at a selected location in Hokkaido, Japan. Ixodes persulcatus (adult and nymph) and I. ovatus (adult) were the common ticks on sika deer. Spirochetes were detected in the midgut of the ticks by the indirect peroxidase-conjugated antibody staining method and by dark-field microscopy after cultivation. By the reactive pattern of monoclonal antibodies, isolates were considered to belong to Borrelia garinii or B. japonica. In an antibody test, the percentage of seropositive deer was 69.0%. Most of the adult sika deer were positive for antibodies to the spirochetes. There are significant age-dependency in antibody level and seropositive rate. The surveillance of deer should be valuable in monitoring the transmission risk of B. burgdorferi sensu lato in nature.     

Evaluation of multiple behavioral responses of sika deer to human hunting pressures

Several ungulate populations have become overabundant worldwide, resulting in ecological and social effects. Wildlife managers must establish effective population control programs to mitigate these negative influences. Hunting is a significant mortality factor for ungulates, which exhibit sensitive behavioral responses toward hunting activities. Wildlife managers need a comprehensive understanding of the ungulate responses to different hunting pressures across seasons. We developed a conceptual method to evaluate multiple behavioral responses to human hunting pressures and applied this to sika deer (Cervus nippon) in Hokkaido, Japan, during August and November in 2015. We measured flight behavior, spatial avoidance, and temporal activity shift during non-hunting and hunting seasons in 4 regions with different hunting pressures. Although we did not observe a clear difference in flight initiation distance among study areas or seasons, sika deer showed significant spatial avoidance during the hunting season in areas with high hunting pressure. Furthermore, sika deer were more active at night in areas with higher hunting pressures, regardless of the season. Collectively, these results suggest that sika deer responded to hunting pressure by changing diel activity to nocturnal throughout the year and avoiding risky areas (i.e., around hunting roads) during hunting season, rather than by increasing flight distance when they encounter humans. Our method can be used for a more efficient population control program for wildlife managers, as it considers the spatiotemporal variations of flexible ungulate behaviors in response to hunting pressures.     

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 variations in physiological indices of adult female white-tailed deer in Texas

Seasonal variations in blood chemistry, urine chemistry, fat reserves, and crude protein levels of rumen contents were determined for free-ranging adult female white-tailed deer (Odocoileus virginianus Zimmermann) in central Texas. Seasonal variations (P less than 0.05) existed for serum total protein, albumin, globulin, albumin/globulin ratios, blood urea nitrogen (BUN), cholesterol, alkaline phosphatase, creatinine, phosphorus, and sodium; and urinary urea/creatinine (U/C) ratios, rumen crude protein, the kidney fat index (KFI), femur marrow fat (FMF), and dressed weights. Variations in BUN, urinary U/C ratios, dressed weights, KFI, and FMF were attributed partially to the nutritional demands of late gestation and lactation.     

A half a century of measuring ungulate body condition using indices: is it time for a change?

From a literature review of five wildlife ecology journals since 1937, we document how using indices to monitor ungulate body condition is common practice, with the kidney fat index (KFI = weight of fat around the kidneys/weight of kidneys without fat × 100) as the favoured tool (82% of studies). In this context, we highlight the problems of using indices when underlying statistical assumptions are not met (isometry, parallel slopes between treatments). We show, with real and simulated data for two cervids with contrasting fat storage strategies, how results from analysis of variance of KFI values differ from analysis of covariance (ANCOVA) of raw data. We conclude that the KFI is affected by the restrictions typically associated with derived index values, and as a consequence, statistical analysis of the KFI could generate spurious results leading to erroneous interpretations concerning variation in body condition of ungulate populations. Thus, we recommend analysing fat weight as an untransformed variable in ANCOVA (kidney weight as covariate) to describe body condition variation in ungulates. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Two Genetically Distinct Lineages of the Sika Deer, Cervus nippon, in Japanese Islands: Comparison of Mitochondrial D-Loop Region Sequences

To investigate genetic diversity among populations of the sika deer, Cervus nippon, nucleotide sequences (705–824 bases) of the mitochondrial D-loop regions were determined in animals from 13 localities in the Japanese islands. Phylogenetic trees constructed by the sequences indicated that the Japanese sika deer is separated into two distinct lineages: the northern Japan group (the Hokkaido island and most of the Honshu mainland) and the southern Japan group (a part of the southern Honshu mainland, the Kyushu island, and small islands around the Kyushu island). All sika deer examined in this study shared four to seven units of repetitive sequences (37 to 40 bases each) within the D-loop sequences. The number of tandem repeats was different among the populations, and it was specific to each population. Six or seven repeats occurred in populations of the northern Japan group, while four or five repeats occurred in populations of the southern Japan group. Each repeat unit included several nucleotide substitutions, compared with others, and 26 types were identified from 31 animals. Sequences of the first, second, and third units in arrays were clearly different between the northern and the southern groups. Based on these D-loop data, colonization and separation of the sika deer populations in the Japanese islands were estimated to have occurred less than 0.5 million years before present. Our results provide an invaluable insight into better understanding the evolutionary history, phylogeny, taxonomy, and population genetics of the sika deer.     

Prevalence of Toxoplasma gondii and Neospora caninum in sika deer from eastern Hokkaido, Japan

Brain and serum were collected from 120 and 12 free-ranging sika deer (Cervus nippon yesoensis), respectively, from six regions in eastern Hokkaido during controlled hunts in the autumn of 2003. Brains were tested for Neospora caninum and Toxoplasma gondii DNA by polymerase chain reaction (PCR) assays. Antibodies to Toxoplasma gondii were measured by means of a latex agglutination test. No brain tested positive for either type of DNA, and no antibody to Toxoplasma gondii was detected in serum, suggesting a low prevalence of infection with these organisms in free-ranging sika deer from eastern Hokkaido. Further examination of multiple tissues by PCR and serologic surveys will be necessary to confirm this.     

Increased brown bear predation on sika deer fawns following a deer population irruption in eastern Hokkaido, Japan

By the 1970s, brown bears (Ursus arctos) in Hokkaido, northern Japan, were opportunistic omnivores that mainly depended on plant materials. Because the sika deer (Cervus nippon) population irrupted in eastern Hokkaido in the 1990s, we expected that brown bears might prey on sika deer fawns. First, we developed a simple and cost-effective method of monitoring possible bear predation on deer fawns by analyzing the widths of deer hairs remained in bear scats. Based on hair thickness standards, we distinguished the brown bear consumption of deer fawns from adults by analyzing bear scats (n?=?108) collected during the deer birthing season (late May?Clate July) in 1999?C2008. To evaluate the importance of fawns to bears, we compared the occurrence of fawn and adult deer hairs in bear scats among three periods (I, 1999?C2000; II, 2003?C2005; III, 2006?C2008) in eastern Hokkaido. The occurrence of fawn hairs in bear scats increased from 12.5 to 27.3?% in volume and from 6.3 to 33.6?% in frequency from period I to period III, whereas adult hairs in scats decreased from 42.8 to 26.1?% in volume and from 34.4 to 22.7?% in frequency during the same time. These data suggest that bears increasingly preyed on deer fawns after the deer population irruption and decreasingly used adult carcasses because of the enforcement of deer carcass treatment by the Hokkaido government.     

Differential effects of ruminally protected amino acids on fattening of fallow deer in two culling periods

A well-balanced amino acid profile in the feedstuffs for livestock is essential to support adequate growth. This is well studied for monogastric species but still not well understood for ruminants and especially for the most unconventional species, like cervids. This study investigated the influence of ruminally protected lysine (Lys) and methionine (Met) supplementation during the fattening period, as well as two slaughter seasons (late autumn (LA) v. late winter (LW)), on the growth, carcass traits, body condition and blood plasma metabolites of fallow deer (Dama dama). Forty-five yearlings of fallow deer bucks were allocated into three groups, balanced by weight (40.2 ± 2.7 kg). The deer were pasture-fed and supplemented with barley, free-choice mineral premix, silage during the winter period, and varying levels of ruminally protected Lys and Met: no amino acids (Control), 9 g/day of Lys, and 9 g/day of Lys plus 3 g/day of Met (Lys+Met). Animals were slaughtered in two separate seasons, LA (six animals per group), and LW (nine animals per group). Animals culled in LA had higher average daily weight gain than LW (P = 0.002), due to the reduced growth during winter typical for seasonal cervids in temperate zone, mediated by the photoperiod. Dressing percentage was significantly higher in LW and in the Lys+Met group (P = 0.002). Body condition score (P = 0.024), kidney fat index (KFI) (P = 0.005), and internal fat (P < 0.001) increased significantly with Lys+Met supplementation. During LW, KFI (P = 0.004) and kidney fat (P = 0.001) were also significantly higher than in LA. Blood creatinine concentration increased significantly for deer receiving Lys (P = 0.002) and Lys+Met (P < 0.001). Also, triglycerides level increased in Lys group (P < 0.001). These findings highlight the effects of Lys and Met supplementation on the growth and internal fat storage for winter survival, suggesting a different use of the supplemented resource according to the season. Also, the observed effects on protein and fat metabolism of fallow deer may influence the production of farmed animals, and offer interesting insights about the physiology of the species.