Sika Deer Population Research Articles

Annual variation in recruitment rates for the sika deer (Cervus nippon) population in eastern Hokkaido, Japan

Annual variation in recruitment rates for the sika deer (<i>Cervus nippon</i>) population in eastern Hokkaido, Japan

Insights from homozygous signatures of cervus nippon revealed genetic architecture for components of fitness.

This study investigates the genomic landscape of Sika deer populations, emphasizing the detection and characterization of runs of homozygosity (ROH) and their contribution towards components of fitness. Using 85,001 high-confidence SNPs, the investigation into ROH distribution unveiled nuanced patterns of autozygosity across individuals especially in 2 out of the 8 farms, exhibiting elevated ROH levels and mean genome coverage under ROH segments. The prevalence of shorter ROH segments (0.5-4Mb) suggests historical relatedness and potential selective pressures within these populations. Intriguingly, despite observed variations in ROH profiles, the overall genomic inbreeding coefficient (FROH) remained relatively low across all farms, indicating a discernible degree of genetic exchange and effective mitigation of inbreeding within the studied Sika deer populations. Consensus ROH (cROH) were found to harbor genes for important functions viz., EGFLAM gene which is involved in the vision function of the eye, SKP2 gene which regulates cell cycle, CAPSL involved in adipogenesis, SPEF2 which is essential for sperm flagellar assembly, DCLK3 involved in the heat stress. This first ever study on ROH in Sika deer, to shed light on the adaptive role of genes in these homozygous regions. The insights garnered from this study have broader implications in the management of genetic diversity in this vulnerable species.

The long‐term drive count and culling data of the sika deer (Cervus nippon) population introduced on Nakanoshima Island in Lake Toya, Hokkaido, Japan, during 1980–2023

AbstractCervid populations introduced to favorable habitats in confinement often increase excessively without predators and hunting. Overabundant deer populations impact the ecosystems and may cause damages to agriculture and forestry. Long‐term count data on the changes in a deer population is essential to understand the relationship between the population dynamics and the natural vegetation. The introduced sika deer (Cervus nippon Temminck, 1836) population without predators on Nakanoshima Island, Hokkaido, Japan, showed repeated irruptions and declines with mass mortality and irregular culling between 1980s and 2000s. The overabundant deer significantly altered the natural vegetation, and density‐dependent changes in population parameters such as body size and reproduction were observed. Here, we present the drive count and culling data to examine the population dynamics during 1980–2023. Deer were counted by 20–30 walking drivers and 2–3 observers on boats once per year in February or March. The number of counted deer rapidly increased from the original three introduced around 1960 to &gt;270 deer (the first peak) in two decades and decreased by half due to starvation and the first culling. Thereafter, the number of counted deer continued to increase with a lower growth rate, reached a higher peak (&gt;400, the second peak) than the first irruption in two decades, and decreased again by half due to starvation and the second culling. Although the number of counted deer increased again up to &gt;300 in several years, it decreased and was maintained at around 100 deer with the annual culling program since 2012. The complete data set for this abstract published in the Data Article section of the journal is available in electronic format in MetaCat in JaLTER at http://db.cger.nies.go.jp/JaLTER/metacat/metacat/ERDP-2024-06.1/jalter-en.

Effects of soil environmental changes accompanying soil erosion on the soil prokaryotes and fungi of cool temperate forests in Southern Japan

ABSTRACT Soil erosion, which involves the degradation of the physical and chemical properties of soil, is a major threat to the soil environment. Although the effects of soil erosion on the physical or chemical properties of forests have been studied, little has been reported on the soil microbial community, which is likely to affect forest ecosystems. This study aimed to elucidate how the microbiome changed with the soil environment accompanying soil erosion in cool temperate mixed forests in Southern Japan, where soil erosion has been accelerated by the increased population of sika deer. We investigated the soil microbial communities of the different soil erosion intensities at three forest sites. In prokaryotic communities, diversity indices were increased with the sum of the height of exposed roots (SUMH), an index of soil erosion. In fungal communities, the relative abundances of plant pathogenic and wood saprotroph fungi were increased as SUMH increased and those of symbiotrophs and ectomycorrhizal fungi were increased with humus organic matter content, suggesting that the difficulties in establishing plants would be increased as soil erosion progressed because of the changes in the composition and function of fungal communities in eroded areas. Moreover, soil fungal communities had a more complex co-occurrence network than that of prokaryote, suggesting that the effects of soil erosion on fungal network is smaller than those on bacterial network. Changes in the soil environment induced by soil erosion altered the microbiomes in the deeper layers of the soil and had different effect on prokaryotes and fungi.

HISTORICAL ANALYSIS OF THE IMPACT OF THE SIKA DEER (CERVUS NIPPON) POPULATION ON THE GEOMETRID MOTHS FAUNA (LEPIDOPTERA: GEOMETRIDAE) OF THE ASKOLD ISLAND (PRIMORSKY KRAI)

Comparing of check lists of species of geometrid moths (Lepidoptera: Geometridae) collected on the Askold Island (Peter the Great Bay, Russian Far East) in 1878– 1873 and in 2021, revealed a low level of their intersection at 43.4%. An attempt to explain the significant historical change in the moth fauna by the impact on the ecosystems of the island of the local population of sika deer (Cervus nippon Temminck, 1838) was made. These deer here trends to episodic sharp increases in numbers, leading to significant damage to the vegetation cover on the island. Based on comparative areaological and ecological analyses of the old and new lists of geometrid moths, no changes have been identified that can be linked with the direct influence of deer on the population of the moths on the Askold Island. However, strong decline numbers of individuals during periods of high deer abundance, which draw indigenous populations of moths into an "extinction whirlpool", can explain the high rate of change of the moth fauna on the island.

Do Feed Plants Provide Sufficient Sodium, Calcium and Magnesium to Sika Deer in Japan? An Analysis Using Global Plant Trait Data

Deficient minerals in overabundant populations could act as an attractant to cull sika deer (Cervus nippon). Because selective culling of female deer is reported to be effective in reducing sika deer populations, it is particularly important to clarify the differences in mineral requirements between males and females. Here, using global plant trait data and a published list of sika deer feed plants in Japan, we estimated whether feed plants provide sika deer sufficient sodium (Na), calcium (Ca) and magnesium (Mg), and compared the results between males and females. An analysis of 191 feed plant species suggested that feed plants can provide sufficient Mg, whereas sufficient Na and Ca is not always provided, especially when the intake is small or the deer large. Na deficiency was more intense for lactating females than males, suggesting that Na can be an effective attractant for selectively culling female deer. In summary, this study demonstrated that sika deer in Japan might require extra Na and Ca sources in addition to feed plants, and therefore these minerals could be useful for developing effective culling methods.

Food or rut: contrasting seasonal patterns in fat deposition between males and females of northern and southern sika deer populations in Japan

Abstract Overwintering is important for the survival of northern mammals, and northern ungulates deposit body fat. Researchers have interpreted fat deposition as an adaptation to food shortages during winter. However, it is likely that reproductive activities also affect fat deposition. We compared kidney fat indices (KFIs) of sika deer (Cervus nippon) between the northern and southern populations in Japan. In the northern population, the KFIs of adult males and females peaked during summer and autumn, respectively. In adult males, the KFIs abruptly declined during the rut (October), while in yearling males and fawns, they were low in summer. In the southern population, KFIs of adult males were high in summer but decreased in October. KFIs of adult females were low and increased in December–January. KFIs of fawns were low. These results suggest that most classes of the southern population did not deposit much fat during the summer except for adult males. The result that southern adult males displayed as much fat deposition as the northern males suggests that body fat was deposited not only for overwintering but also for reproductive activity of adult males.

Gait Patterns in Snow—a Possible Criterion to Differentiate Sika Deer and Japanese Serow Tracks

There is a compelling need to develop user-friendly and sensitive techniques to monitor sika deer (Cervus nippon) populations in snowy regions, where initial stages of deer invasion have been observed. In snow, we can easily detect footsteps of terrestrial mammals, which often serve as a useful index of population size. Here, we examined the possibility of identifying tracks with similar hoof prints left by two sympatric ungulates, sika deer and Japanese serow (Capricornis crispus), using gait patterns. We then recorded tracks of free-ranging deer and serows on the snow by following ∼200-km survey routes in the Tohoku region. We successfully recorded the gait patterns of 27 deer and 34 serows. Our key findings were as follows: 1) the step width of deer tracks (mean and SE, 20.3 ± 0.7 cm) was substantially narrower than that of serow tracks (26.9 ± 0.8 cm); 2) step width was less sensitive to body size and ground conditions for both species; and 3) the step width of 22.5 cm became an optimal threshold to maintain a reasonable classification accuracy (> 80%) for both species. Thus, the gait patterns serve as a possible criterion for identifying the tracks of these two ungulates.

Interspecific association of sika deer in terrestrial animal communities of Liancheng National Nature Reserve, China.

The prevention and control of invasive of alien species is an important work for nature reserves. This study analyzes the development trend of the alien species sika deer in Liancheng National Nature Reserve. From October 2019 to June 2020, 3523 valid photos and videos of terrestrial animals were acquired from 130 camera traps, and sika deer were recorded in 21 photos from 13 traps. The survival of the sika deer population was investigated by means of morphological identification, population structure analysis, species relative abundance indices, and species spatial association analysis. A total of 13 sika deer individuals were identified by camera trapping, including two kids and three subadults representing the reproductive capacity of the population. Spatially, sika deer is not associated with any local species and was outside the spatial association network of terrestrial animals in Liancheng National Nature Reserve, indicating that the sika deer population has not been integrated into the local community and has failed to perform its ecological function. It is worth noting that the reserve provides habitat suitable for sika deer and that the population has adequate reproductive capacity. Due to the lack of large apex predators in the reserve, the population size of ungulates such as sika deer, red deer, and Siberian roe deer may expand and lead to population outbreaks and the associated problems for the ecosystem. To restore large- and medium-sized carnivores and avoid the population outbreak of the species, the present challenges require immediate attention in Liancheng National Nature Reserve.

Characterization of quinolone-resistant and extended-spectrum β-lactamase-producing Escherichia coli derived from sika deer populations of the Nara Prefecture, Japan.

Wildlife in urban areas have the potential to disseminate antimicrobial-resistant bacteria (ARB) across a wider environment. Using antimicrobial-supplemented agar plates, we isolated extended-spectrum β-lactamase-producing Escherichia coli (EEC) and quinolone-resistant E. coli (QREC) from 144, 23, and 30 deer feces from Nara Park (NP), rural area neighboring NP (RA), and Mt. Odaigahara (MO), respectively. In NP and RA, the prevalence of EEC was 24.3 and 4.3%, respectively; that of QREC was 11.1 and 17.4%, respectively. Neither EEC nor QREC were detected in MO. The pulsotypes of EEC and QREC isolates differed between NP and RA. Our study suggests that deer of the Nara Prefecture are potential carriers of ARB, but long-distance dissemination is unlikely due to limited deer movement.

Experience of the prefecture with hunting management influences the effectiveness of wildlife policy

AbstractOverabundant ungulate populations have impacted forestry and agricultural systems, as well as natural ecosystems, worldwide. To effectively control the sika deer (Cervus nippon) and wild boar (Sus scrofa) populations, which are currently under limited hunting pressure in Japan, we evaluated the prefectures' past management experiences with 2 wildlife laws: a prefecture‐determined management system for relaxing hunting regulations implemented in 2000 and municipality‐determined damage control system for subsidized culling implemented in 2008. Time series data (1990–2014) of sika deer and wild boar harvest per hunter for each prefecture were grouped using dynamic time warping clustering analyses. All groups of both ungulates demonstrated significant increases in harvest per hunter after implementing both laws. The prefectures with the most experience in deer management could control sika deer populations through management planning, culling supported by subsidies, and enforcement of antlerless deer harvest. The strategies are likely ineffective for controlling wild boar populations because of the lack of effective selective harvesting and limited survey methods for population monitoring. Our findings suggest that prefectures' experience in hunting management influences the success of population reduction actions for sika deer.

A 17-Year Study of the Response of Populations to Different Patterns in Antlerless Proportion of Imposed Culls: Antlerless Culling Reduces Overabundant Deer Population.

Increasing populations of large herbivores have caused environmental damage around the world, and it is necessary to improve population management strategies. Culling is a traditional management method. Antlerless deer proportions, consisting of adult female deer and fawn in Cervidae in wildlife statistics, are directly related to population increases; thus, the culling-based removal of individuals from habitats and the removal of these antlerless individuals by game hunting and nuisance control might be effective approaches for reducing population sizes. We evaluated the effectiveness of antlerless culling on 17-year density trends in the sika deer (Cervus nippon) population across an area of 1175 km2 in Fukuoka Prefecture (Japan). In 11 out of 47 grids (area measuring 5 by 5 km), the densities of sika deer tended to decline; meanwhile, in the remaining 36 grids, the densities increased. These density trends were explained by changes in the proportion of antlerless culling, as the densities declined with increasing proportions of antlerless deer. The results affirm the theory that antlerless culling is effective in population management; it is posited that antlerless-biased culling could be a crucial measure in managing overabundant populations of herbivores, contributing to more effective conservation of forest environments.

Concordant genetic structures of sika deer and Japanese land leeches suggest that the current range expansion of Haemadipsa japonica is dependent on sika deer migration: A case study from Tochigi Prefecture, Japan

AbstractHaemadipsa japonica is a Japanese land leech that feeds on the blood of host animals, mainly the sika deer (Cervus nippon). The distribution of H. japonica has expanded since the 1990s, possibly due to sika deer population increases. Haemadipsa japonica populations were found in the northern and southern regions of Tochigi Prefecture, central Japan. Previous investigations reported that these populations are genetically differentiated between the north and south, although the sika deer distribution extends throughout the northern and southern regions. We hypothesized that the migration of sika deer might be limited, thus maintaining the two H. japonica genetic groups and restricting its range expansion. We evaluated this hypothesis by investigating the genetic structure of the mitochondrial DNA (mtDNA) and nuclear microsatellites (nSSR) of sika deer samples collected from Tochigi Prefecture and from H. japonica bloodmeal samples (invertebrate‐derived DNA; iDNA). The sika deer mtDNA presented two haplotypes (G‐ and A‐haplotypes) without a clear genetic structure. Conversely, the sika deer nSSR analysis indicated clear genetic differentiation between deer in the northern and southern regions, corresponding to the two H. japonica genetic groups. This indicates that sika deer movement is restricted to narrow regions in Tochigi Prefecture. Therefore, we conclude that the current H. japonica expansion in the prefecture likely depends on the migration of sika deer, only occurring within the northern and southern regions, even though this is driven by sika deer migration.

Importance of Host Abundance and Microhabitat in Tick Abundance.

To reduce the risk of zoonoses, it is necessary to understand the infection process, including the ecology of animals and vectors (i.e., the 'One Health' approach). In temperate climates, ticks are the major vectors of zoonoses, so factors determining their abundance, such as host mammal abundance and microhabitat conditions, should be clarified. Sika deer (Cervus nippon) are a major tick host and are rapidly expanding their distribution in Japan. We established 12 plots along a gradient of sika deer abundance in Tochigi Prefecture, Japan. We monitored the occurrence of mammal species with camera traps and sampled questing ticks on a monthly basis by flagging along three transects (center of a trail, forest edge, and forest interior) at each site from April to November 2018. The camera traps recorded 12 mammal species, predominantly sika deer. Five Haemaphysalis species and three Ixodes species were sampled. The numbers of ticks sampled were explained by the photographic frequency of sika deer, and partly by that of other mammal species, depending on tick species and their developmental stages. The numbers of sampled adult and nymphal ticks were the highest at the forest edge, where vegetation cover was greatest. Thus, vegetation management in tick habitats and the control of sika deer populations may reduce tick abundance.

DRONE REMOTE SENSING FOR THE CONTROLLED CAPTURE OF SIKA DEER (CERVUS NIPPON): CASE STUDY IN VILLAGE OF YAMANAKAKO

Abstract. In recent years, the population of sika deer in Japan has been increasing, causing animal damage. As for sika deer in the vicinity of the village of Yamanakako, Yamanashi Prefecture, although the total number of individuals is on a downward trend due to the controlled capture that has been conducted throughout the year since 2009, the number of individuals (population) that stay in the vicinity of residential areas (villa areas) has been increasing in recent years. Unmanned aerial vehicle (UAV) or drone has been proven as an effective tool in wildlife research. In particular, thermal images are useful for relatively large mammals such as deer. In this paper, the utility of drone remote sensing using RGB and thermal video is tested for controlled capture of sika deer as a case study in the village of Yamanakako. We develop a methodology to acquire data and to visually identify sika deer specifically for this mission. As a result, the drone remote sensing was considered successful completing within 1 hour and identifying 25 sika deer individuals. Thermal video format was effective to visually identify sika deer on site in terms of time savings, compared to RGB video or RGB/thermal still image format. To have flight area grided and hovering 3 seconds at the centre of a grid during the flight was essential both for visually identifying the number and location of sika deer and for sharing such information later with beaters and shooters using a map.

A 25-Year Study of the Population Dynamics of a Harvested Population of Sika Deer on Kyushu Island, Japan

Sika deer (Cervus nippon) populations have damaged habitats, agricultural crops, and commercial forests in many parts of the world, including Asia, Europe, northern America, and New Zealand. Population management of sika deer is an important task in those areas. To better understand large-scale management and improve management efficiency, the authors estimated spatio-temporal changes of density distribution and population dynamics of a managed population of sika deer on Kyushu Island (approximately 36,750 km2), Japan. The authors estimated these changes by using fecal pellet count surveys conducted from 1995 to 2019 and results from a vector autoregressive spatio-temporal model. No decreasing trend of populations were observed at the island and prefectural scales, even though the management goal has been to reduce the population by half, and harvesting on the island increased annually until it reached about 110,000 sika deer in 2014. A possible explanation for the stable population dynamics is that the population used to determine the harvest number under the prefectural management plan was originally underestimated. This study highlights not only the difficulties of wide-area management of sika deer but also three important factors for successful management: reducing the risk of management failure, using an adaptive management approach, and appropriate management scale.

Molecular Evidence Reveals the Sympatric Distribution of Cervus nippon yakushimae and Cervus nippon taiouanus on Jeju Island, South Korea.

Simple SummaryThe sika deer (Cervus nippon) was introduced in South Korea from Japan and Taiwan for commercial farming. They have become invasive to mainland South Korea and Jeju Island due to escape from confinement and illegal release. Native species and ecosystems may be threatened by the presence of non-native species. To deal with ecological risk and evolutionary processes, information on the phylogeny of these non-native sika deer is necessary. Genetic studies using mitochondrial DNA cytochrome B (CytB) gene sequences were conducted to determine the subspecies of Jeju sika deer and their phylogenetic relationship. On Jeju Island, we confirmed the presence of two distinct groups of CytB haplotypes: Cervus nippon yakushimae, native sika to Japan, and Cervus nippon taiouanus, native to Taiwan.Non-native species threaten native ecosystems and species, particularly on islands where rates of endemism and vulnerability to threats are high. Understanding species invasion will aid in providing insights into ecological and evolutionary processes. To identify the non-native sika deer (Cervus nippon) population in Jeju, South Korea, and their phylogenetic affinities, we collected tissue samples from roadkill and the World Natural Heritage Headquarters in Jeju. Mitochondrial DNA cytochrome B (CytB) gene sequences were analyzed to determine two distinct CytB haplotypes. Phylogenetic analysis using maximum likelihood tree revealed two haplotypes of CytB clustered into two different groups representing two subspecies: C. n. yakushimae, native to Japan, and C. n. taiouanus, native to Taiwan. The tentative divergence time between the two subspecies was estimated at 1.81 million years. Our study confirmed that the two subspecies of sika deer are sympatric in the natural ecosystem of Jeju Island. This study provides valuable information to help government and conservation agencies understand alien species and determine control policies for conserving native biodiversity in South Korea.

Scots pine (Pinus sylvestris L.) demonstrates a high resistance against bark stripping damage

Bark stripping damage reduces timber quality due to fungal infection and structural defects. Weakened stems may break and induce the death of trees, which strongly affects forest stability. Some tree species, such as Norway spruce (Picea abies [L.] Karst.), are highly susceptible to bark stripping, but Scots pine (Pinus sylvestris L.) has been studied to a lesser extent. The objective of this study was to predict the effect of the degree of bark stripping damage and rot on the production parameters of Scots pine and to determine the influence of climatic factors on various damaged trees. The research was conducted on 15 pine forest stands aged 40–42 years with a numerous sika deer (Cervusnippon nippon) population in the western part of the Czech Republic (425–492 m a.s.l.). The results showed significant differences in tree diameter and volume (but not height) between healthy and extensively damaged trees according to 417 pines measured. However, no differences were found between lightly damaged trees. Similarly, circumference damage did not significantly affect mean tree stem volume, in contrast to previously reported results for Norway spruce. The trees were first damaged by deer at the age of 18.5 years on average. According to the prediction model based on 40 felled and sampled trees, rot did not reach a distance > 50 cm from the site of the bark stripping on the stem, with a mean speed of vertical spreading of 0.9 cm yr−1. Concerning the effect of climatic factors on radial growth (60 core samples taken), the difference between healthy and minor to extensively damaged trees was negligible. However, healthy trees responded more to the effects of temperature, and damaged trees were more sensitive to the precipitation amounts. Scots pine appears to be a suitable tree species for afforestation in areas with high game pressure during continuing climate change.

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

AbstractOmnivores 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 (&gt;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.

Diel and monthly activity pattern of brown bears and sika deer in the Shiretoko Peninsula, Hokkaido, Japan.

Mammals exhibit several types of diel activity pattern, including nocturnal, diurnal, crepuscular, and cathemeral. These patterns vary inter- and intra-specifically and are affected by environmental factors, individual status, and interactions with other individuals or species. Determining the factors that shape diel activity patterns is challenging but essential for understanding the behavioral ecology of animal species, and for wildlife conservation and management. Using camera-trap surveys, we investigated the species distributions and activity patterns of terrestrial mammals on the Shiretoko Peninsula, Hokkaido, Japan, with particular focus on brown bears and sika deer. From June to October 2019, a total of 7,530 observations were recorded by 65 camera-traps for eight species, including two alien species. The diel activity pattern of brown bears was diurnal/crepuscular, similar to that of bears in North America, but different from European populations. Bear observations were more frequent during the autumnal hyperphagia period, and adult females and sub-adults were more diurnal than adult males. In addition, bears inside the protected area were more diurnal than those outside it. These findings suggest that appetite motivation, competitive interactions between conspecifics, and human activities potentially affect bear activity patterns. Similar to other sika deer populations and other deer species, the diel activity patterns of sika deer were crepuscular. Deer showed less variation in activity patterns among months and sex-age classes, while adult males were observed more frequently during the autumn copulation period, suggesting that reproductive motivation affects their activity patterns.