Iriomote Cat Research Articles

Seasonal diet partition among top predators of a small island, Iriomote Island in the Ryukyu Archipelago, Japan

Small islands tend to lack predators because species at higher trophic levels often cannot survive. However, two exceptional top predators—the Iriomote cat Prionailurus bengalensis iriomotensis, and the Crested Serpent Eagle Spilornis cheela perplexus—live on the small Iriomote Island in the Ryukyu Archipelago. To understand how these predators coexist with limited resources, we focused on their seasonal diets between which conflicts are considered to occur. To compare the diets, we used DNA metabarcoding analysis of faecal samples. In the summer, we identified 16 unique prey items from Iriomote cat faecal samples and 15 unique prey items from Crested Serpent Eagle faecal samples. In the winter, we identified 37 and 14, respectively. Using a non-metric multidimensional scaling and a permutational multivariate analysis of variance, our study reveals significant differences in the diet composition at the order level between the predators during both seasons. Furthermore, although some prey items at the species-to-order level overlapped between them, the frequency of occurrence of most prey items differed in both seasons. These results suggest that this difference in diets is one of the reasons why the Iriomote cat and the Crested Serpent Eagle are able to coexist on such a small island.

The hard tick fauna (Acari: Ixodida) of the Iriomote cat (<I>Prionailurus bengalensis iriomotensis</I>) in Iriomote Island, Okinawa Prefecture, Japan: a literature review with emphasis on need for surveillance of tick-borne pathogens

The hard tick fauna (Acari: Ixodida) of the Iriomote cat (<I>Prionailurus bengalensis iriomotensis</I>) in Iriomote Island, Okinawa Prefecture, Japan: a literature review with emphasis on need for surveillance of tick-borne pathogens

A comparative profile of urinary scent signals of two endangered Japanese populations of leopard cat

Two subspecies of mainland leopard cats (Prionailurus bengalensis), Iriomote cats (Prionailurus bengalensis iriomotensis), and Tsushima leopard cats (Prionailurus bengalensis euptilurus), are small, endangered felids that are endemic to the Japanese islands, Iriomote-jima and Tsushima, respectively. Both subspecies have an estimated population size of only about 100 individuals each. Therefore, it is crucial to expand our understanding of these subspecies to successfully conserve them. While their morphology, anatomy, ecology, pathology, and genetics are well studied, little is known about their physiology regulated in subspecies-specific manners. This study characterized their urinary volatile and nonvolatile organic compounds, with which individuals express their physiological status and territorial ownership. We found significantly higher levels of 3-mercapto-3-methyl-1-butanol and its structural analogs, which are scent signals of domestic cats, in the urinary headspace of Iriomote cats than in that of Tsushima leopard cats. There were no differences in the urinary levels of felinine, an amino acid that acts as a precursor of 3-mercapto-3-methyl-1-butanol, suggesting the variation of catalytic activities for decomposing felinine to 3-mercapto-3-methyl-1-butanol between subspecies. Both subspecies exhibited physiological proteinuria due to the secretion of carboxylesterase 5A, also known as cauxin, for the production of felinine. In conclusion, while the two endangered Japanese subspecies of mainland leopard cats share similar genetic backgrounds, urinary contents of metabolites vary between the subspecies. We suggest that after the separation into two subspecies, the regulation of the metabolic pathway for 3-mercapto-3-methyl-1-butanol production likely evolved differently in each subspecies in response to their specific environments.

Serological survey of Toxoplasma gondii infection in endangered Iriomote cat (Prionailurus bengalensis iriomotensis) and simulation of the effect on population dynamics

Serological survey of Toxoplasma gondii infection in endangered Iriomote cat (Prionailurus bengalensis iriomotensis) and simulation of the effect on population dynamics

Fecal Glucocorticoid Metabolites as a Noninvasive Indicator of Stress in the Tsushima Leopard Cats (Prionailurus bengalensis euptilurus): Application to Health Care.

Simple SummaryThe Tsushima leopard cat (Prionailurus bengalensis euptilurus) and the Iriomote cat (P. b. iriomotensis) are the only two wild felids living in Japan. Both species are endangered. The Tsushima leopard cat is undergoing captive breeding (ex situ conservation) in zoos with the aim of returning it to the wild, in addition to conservation activities in the habitat (in situ conservation). In order to promote captive breeding, it is important to elucidate the reproductive physiology and to evaluate stress conditions. We investigated the possibility of measuring glucocorticoid metabolites (GCMs), which are stress hormones, using feces in Tsushima leopard cats. We examined changes in fecal GCM in individuals who underwent a health examination under anesthesia as an unavoidable stressful condition during normal health care. Fecal GCM concentrations increased 1–2 days after the health examination. Fecal GCM concentrations were higher in diseased individuals than in apparently healthy individuals. Individuals diagnosed with disk herniation also showed a decrease in fecal GCM concentrations after treatment with therapeutics. These results indicate that the measurement of fecal GCMs is useful for improving the husbandry and health management of the Tsushima leopard cat.This study investigates whether the measurement of glucocorticoid metabolites (GCMs) in feces is a useful method for the noninvasive evaluation of stress in the endangered Tsushima leopard cats (Prionailurus bengalensis euptilurus). Feces were collected from six seemingly healthy and five diseased (renal dysfunction, adrenal tumor, hernia, feline immunodeficiency virus (FIV), feline leukemia virus (FeLV)) Tsushima leopard cats in captivity. Fecal GCMs were measured by enzyme immunoassay (EIA) for cortisol. Individuals that experienced a physical examination under anesthesia showed increased fecal GCMs 1–2 days after the event. An individual diagnosed with disk herniation showed decreased fecal GCMs after medical administration. The mean fecal GCM concentrations for six healthy animals and five diseased animals were 0.66 ± 0.08 and 2.65 ± 0.76 μg/g, respectively, which was significantly different. Cortisol and corticosterone were not clearly detected in the feces examined by the use of the HPLC-EIA analysis. GCMs may be excreted in the feces; however, the exact identification of these substances is not achieved. The results suggest that the measurement of fecal GCMs is useful for the husbandry and health management of this species.

西表島世界遺産登録に伴うオーバーツーリズム等の自然環境に対するインパクトを，地域住民との協働によってモニタリングする手法・体制の構築 ―認定特定非営利活動法人トラ・ゾウ保護基金―

西表島世界遺産登録に伴うオーバーツーリズム等の自然環境に対するインパクトを，地域住民との協働によってモニタリングする手法・体制の構築 ―認定特定非営利活動法人トラ・ゾウ保護基金―

Diet analysis of two umbrella species using DNA barcoding to conserve the ecosystem of Iriomote-jima Island ―Iriomote Cat Research Group―

Diet analysis of two umbrella species using DNA barcoding to conserve the ecosystem of Iriomote-jima Island ―Iriomote Cat Research Group―

Adaptations to prey base in the hypercarnivorous leopard cat Prionailurus bengalensis

Investigating biogeographical variations in diet composition can help understand the adaptability and generalism of species. Although the dietary adaptability of omnivorous mesocarnivores is well established, far less work has explored how more specialist hypercarnivores optimise their diets. By reviewing 11 studies of the leopard cat (Prionailurus bengalensis), we quantitatively examined how dietary composition varies over the wide range of biomes they occupy in Asia. Specifically, we contrasted the diet of the Iriomote Island sub-species (south-western Japan), where native rodents are absent, with that of the mainland. Leopard cat diet typically comprised mammals, birds, amphibians, reptiles, and invertebrates. In Iriomote Island, however, the low relative frequency of occurrence of small mammals (only introduced rats) was compensated by higher frequencies of reptiles and amphibians compared to the mainland. Consequently, trophic diversity and dietary niche breadth were higher for leopard cats in Iriomote Island than for the mainland. This shows that even hypercarnivorous species can use trophic plasticity to adapt to local prey availability. Given that rodent numbers often fluctuate substantially over time, the availability of alternative prey, such as herptiles, may be vital for the conservation of the leopard cat, and especially the critically endangered Iriomote cat. More generally, the trophic versatility of hypercarnivores must be considered when assessing their vulnerability to environmental change.

Low genetic variation in the MHC class II DRB gene and MHC-linked microsatellites in endangered island populations of the leopard cat (Prionailurus bengalensis) in Japan.

Isolated populations of the leopard cat (Prionailurus bengalensis) on Tsushima and Iriomote islands in Japan are classified as subspecies P. b. euptilurus and P. b. iriomotensis, respectively. Because both populations have decreased to roughly 100, an understanding of their genetic diversity is essential for conservation. We genotyped MHC class II DRB exon 2 and MHC-linked microsatellite loci to evaluate the diversity of MHC genes in the Tsushima and Iriomote cat populations. We detected ten and four DRB alleles in these populations, respectively. A phylogenetic analysis showed DRB alleles from both populations to be closely related to those in other felid DRB lineages, indicating trans-species polymorphism. The MHC-linked microsatellites were more polymorphic in the Tsushima than in the Iriomote population. The MHC diversity of both leopard cat populations is much lower than in the domestic cat populations on these islands, probably due to inbreeding associated with founder effects, geographical isolation, or genetic drift. Our results predict low resistance of the two endangered populations to new pathogens introduced to the islands.

イリオモテヤマネコ・メスの育仔中の行動圏解析( 哺乳類の行動圏研究の現状と将来及びテレメトリー法データ行動圏解析法)

イリオモテヤマネコ・メスの育仔中の行動圏解析( 哺乳類の行動圏研究の現状と将来及びテレメトリー法データ行動圏解析法)

数値標高モデル(DEM)を用いたイリオモテヤマネコの行動圏利用様式の三次元空間解析の試み( 哺乳類の行動圏研究の現状と将来及びテレメトリー法データ行動圏解析法)

数値標高モデル(DEM)を用いたイリオモテヤマネコの行動圏利用様式の三次元空間解析の試み( 哺乳類の行動圏研究の現状と将来及びテレメトリー法データ行動圏解析法)

The presence of tick-borne diseases in domestic dogs and cats living on Iriomote-jima and Tsushima islands.

The Iriomote cat and Tsushima leopard cat are endangered wildcats in Japan and inhabit only Iriomote-jima and Tsushima islands, respectively. Domestic dogs and cats living on Iriomote-jima and Tsushima islands were surveyed to clarify the interrelationship between wildcats and domestic animals regarding tick-borne disease transmission. Pathogen-derived DNA in blood samples was detected by polymerase chain reaction. Babesia gibsoni was detected in dogs of Iriomote-jima, and Hepatozoon felis and hemoplasmas were detected in domestic cats of Tsushima. Because the H. felis detected in this study was closely related to that isolated from wildcats, we suspect that common H. felis is harbored and transmitted among wildcats and domestic cats via ticks in Tsushima.

Importance of frogs in the diet of the Iriomote cat based on stomach content analysis

This study aimed at providing new insight into the dietary habits of the endangered Iriomote cat (Prionailurus bengalensis iriomotensis) by examining the stomach contents. Using this method allowed for more reliable representation of the diet than the analysis of scat content as used in previous studies of this subspecies. We applied five indices: frequency of occurrence, relative frequency of occurrence, relative weight, relative number of individuals, and occupancy rate of weight in a stomach to design a multifaceted evaluation of diet. A variety of organisms (21 species and six categories in eight classes) were found in the stomachs. Amphibia and Aves occurred in the highest frequency (58.06 % each). The Sakishima rice frog (Fejervarya sakishimensis) was found to be the most frequently consumed prey. Of all classes, only the frequency of occurrence of Amphibia differed significantly between stomach and scat contents (G-test, p < 0.01), which suggests an underestimation of amphibians in the scat analysis. The stomach content analysis allowed for obtaining data on foraging by juvenile Iriomote cats and revealed that young individuals start consuming a variety of animals, including frogs and snakes at the age of 4 to 5 months. This study emphasized the importance of frogs as prey of the Iriomote cat, and as such, it is the first investigation of this cat species based on stomach contents.

Molecular survey of arthropod-borne pathogens in ticks obtained from Japanese wildcats

The Iriomote cat (IC), Prionailurus bengalensis iriomotensis, and the Tsushima leopard cat (TLC), Prionailurus bengalensis euptilurus, are endangered subspecies of leopard cats in Japan. In addition to habitat destruction and road kills, infectious diseases may threaten their populations, and infection with arthropod-borne pathogens has been reported in both subspecies. Infestations with ectoparasites, especially ticks, have frequently been observed in ICs and TLCs. In the present study, ticks collected from captured ICs and TLCs between November 2011 and January 2012 were morphologically identified and the prevalence of the pathogens Bartonella sp., Babesia sp., Ehrlichia sp., Anaplasma sp., Hepatozoon sp., and hemoplasmas in the ticks was molecularly evaluated. The ticks Haemaphysalis longicornis, H. hystricis, and Amblyomma testudinarium were obtained from ICs, and H. megaspinosa, Ixodes tanuki, H. campanulata, and A. testudinarium were collected from TLCs. The pathogens Hepatozoon felis, Babesia sp., and Anaplasma bovis were detected in ticks obtained from ICs, while H. felis. Babesia sp., Ehrlichia sp., E. muris, ‘Candidatus Mycoplasma haemominutum’, and Bartonella henselae were found in ticks from TLCs. To protect and conserve these endangered animals, continuous monitoring and additional surveys will be necessary to understand the role of ticks as disease vectors in Japanese wildcats.

Conservation and management of terrestrial mammals in Japan: its system and practices

Discussion and Conclusions: The proportion of natural forests was reduced to about 40 % of the total area of forests by 2013. The most influential laws for wildlife conservation and management in Japan are the “Act on the Conservation of Endangered Species of Wild Fauna and Flora” and “Wildlife Protection and Proper Hunting Act”. The Amami rabbit (Pentalagus furnessi), the Bonin flying fox ( Pteropus pselaphon), a subspecies of Ryukyu flying fox ( Pteropus dasymallus daitoensis), and two subspecies of the leopard cat (Prionailurus bengalensis iriomotensis and P. b. euptilurus) are conserved under the “Act on Conservation of Endangered Species of Wild Fauna and Flora”, whereas the conservation of many endemic terrestrial species that are ranked high in conservation status are not implemented in Japanese laws. Recently many management practices have been developed for overabundant populations of the sika deer (Cervus nippon) and the wild boar (Sus scrofa) under “Wildlife Protection and Proper Hunting Act”.

Successful DNA Typing of Feces to Determine the Species and Sex of the Endangered Iriomote Cat (Prionailurus bengalensis iriomotensis) by using the 16S rRNA Gene and an SNP Marker in a Zinc-Finger Protein Gene

Successful DNA Typing of Feces to Determine the Species and Sex of the Endangered Iriomote Cat (<i>Prionailurus bengalensis iriomotensis</i>) by using the 16S rRNA Gene and an SNP Marker in a Zinc-Finger Protein Gene

Food Habits of the Leopard Cat (Prionailurus bengalensis euptilurus) in Korea

Prionailurus bengalensis is divided into 12 subspecies from India and Southeast Asia to Russia, which vary clearly in appearance (Nowell and Jackson 1996; Groves 1997). Among them, P. b. euptilurus is reported to inhabit Manchuria, the northeastern part of China, East Russia, Tsushima Islands of Japan, and Korea (Nowell and Jackson 1996). Prionailurus bengalensis is widely distributed but threatened by habitat loss, hunting, and commercial trade in Southeast Asia. Currently, P. bengalensis has been listed and protected under Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES 2011). The subspecies P. b. bengalensis has also been designated as endangered by the United States Department of the Interior (Nowak 1999). In an attempt to understand the status of the wild population, several researchers have focused on this species’ distribution, potential impacts on population dynamics, and feeding behavior (Rabinowitz 1990; Tatara and Doi 1994; Grassman 2000; Rajaratnam 2000; Austin 2002; Grassman et al. 2005; Rajaratnam et al. 2007; Izawa et al. 2009). Prionailurus b. euptilurus became endangered in Korea because of secondary poisoning through un limited use of poisonous rodenticides, such as Fratol (sodium monofluoroacetate), after the Korean War (Won 1967). The leopard cat has been protected in Korea since 1998 from the risk of extinction from habitat loss and traffic accidents. According to Choi (2007), the 103 leopard cats were killed by car accidents from 2004 to 2006. Studies have been conducted in Thailand to investigate the ecological and dietary habits of P. bengalensis (Rabinowitz 1990; Grassman 2000; Austin 2002; Grassman et al. 2005), and feeding strategy studies of P. bengalensis inhabiting Tsushima Islands have been carried out in Japan (Inoue 1972; Tatara and Doi 1994; Izawa et al. 2009). In addition, feeding habits and habitat selection studies have been conducted on Iriomote cats (P. b. iriomotensis) and leopard cats (P. b. borneoensis) (Schmidt et al. 2003; Rajaratnam et al. 2007). Despite that P. bengalensis is a globally threatened species, it has only recently been studied internationally. Since P. b. euptilurus was first referred to as a Chosun animal species by Won (1968), taxonomic studies based on the appearance of P. b. euptilurus have been reported in Korea (Oh 2002). The home ranges and habitat selection of P. b. euptilurus that live in and around artificial landscapes (e.g., roads and small-scale ecological parks) have also been reported (Woo 2010). Until recently, only fragmentary studies of P. b. euptilurus, have become available, with very few basic ecological studies, and baseline data are required for this species in Korea. The aim of this study is to report basic ecological data and information about the prey species of P. b. euptilurus using fecal samples.

Molecular Epidemiologic Survey of Bartonella, Ehrlichia, and Anaplasma Infections in Japanese Iriomote and Tsushima Leopard Cats

The Iriomote cat (IC; Prionailurus iriomotensis) and the Tsushima leopard cat (TLC; Prionailurus bengalensis euptilura) are endangered wild felids in Japan. As a part of ongoing conservation activities, we conducted a molecular, epidemiologic survey of Bartonella, Ehrlichia, and Anaplasma infections in wild IC and TLC populations. Blood samples (47 from 33 individual IC; 22 from 13 TLC) were collected between August 2002 and January 2011. Using PCR analysis, we confirmed the presence of Bartonella henselae in ICs and Bartonella clarridgeiae in TLCs, with prevalences of 6% and 8%, respectively. Using PCR and basic local alignment search tool analyses, we identified Ehrlichia canis in both cats and Anaplasma bovis in TLCs. The prevalence of E. canis was 12% in ICs and 8% in TLCs, and the prevalence of A. bovis was 15% in TLCs. This is the first report, to our knowledge, of B. henselae, B. clarridgeiae, E. canis, and A. bovis infections in these two endangered species. Continuous monitoring of these pathogens is needed for their conservation.

Road use by the Iriomote Cat (Prionailurus bengalensis iriomotensis) on Iriomote-Jima Island in Relation to its Herpetile Prey

The Iriomote cat is an endangered subspecies (CR on the Japanese Red List) found only on Iriomote-jima Island in the Ryukyu Archipelago, Japan. One of the main factors threatening the Iriomote cat is the main paved road that contributes to traffic mortality of this wildcat and also alters its preferred lowland habitats with abundant prey. One of the reasons why the Iriomote cat appears on the road may be due to the presence of prey; therefore, we investigated road use by this wildcat in relation to its prey. In 2009, scat surveys were conducted to assess road use by the Iriomote cat, and prey surveys were undertaken in the morning and at night, mainly targeting terrestrial frogs and reptiles. To analyse the importance of factors related to road use by the Iriomote cat, the influences of prey density along road types, habitat types, presence or absence of road construction activities, and survey regions on number of scats were examined using nested generalised linear models (GLM), assuming Poisson error and a log-link function. Diurnal lizard density was strongly correlated with scat along roads, and the density of road-killed Fejervarya sakishimensis was positively correlated with scat presence along roads.

Epidemiological Survey of Tick-Borne Protozoal Infection in Iriomote Cats and Tsushima Leopard Cats in Japan

This epidemiological survey was conducted to determine the prevalence of Hepatozoon, Babesia and Theileria infection in the Iriomote cat (IC) and the Tsushima leopard cat (TLC). Blood samples from 43 ICs and 14 TLCs were collected between November 2002 and January 2012. Polymerase chain reaction and DNA sequencing analyses detected a Hepatozoon felis infection prevalence of 72.0% (31/43 cats) and 100% (14/14 cats) in ICs and TLCs, respectively. The degree of Hepatozoon parasitemia observed on blood smears ranged from 0.1 to 4.7%. However, no cases had obvious clinical signs of hepatozoonosis. Neither Babesia- nor Theileria-infected wildcats were detected in this study.