Mammal Study

The subfamily Callicebinae is composed of 35 recognized living species that are grouped into the genera, Callicebus, Plecturocebus, and Cheracebus. In this study we assess the taxonomic status of the population of Cheracebus from the Nanay-Tigre interfluvium in Peruvian Amazonia, based on morphological (cranial and pelage) and molecular (mitochondrial DNA) evidence. Following the integrated assessment of the evidence, we conclude that specimens from the Nanay-Tigre interfluvium comprise a distinct lineage at the species level. It is easily distinguished from the other species of the genus, including C. lucifer to which the new species was considered to belong so far, by, among other characters, overall Reddish-brown pelage; crown intense reddish brown; Cream-colored collar, like a bow tie, with a band that does not extend laterally. The description of a new species of Cheracebus is not unexpected since other new species of titi monkeys have been described in recent years and there are several candidate species awaiting validation of their distinction. As such, we anticipate that in the next few years several taxonomic changes will be proposed in order to reveal a classification that mirrors the real species diversity of the subfamily Callicebinae.

The water shrew Chimarrogale platycephala is an endangered species in Japan. Although immediate conservation actions are necessary, detailed information on this species is inadequate. We compared dietary trends obtained via C. platycephala digestive contents analysis with those through stable isotope analysis (δ¹³C, δ¹⁵N, ‰) of non-invasive body hair and invasive muscles to elucidate their diet and evaluate usefulness of the dietary stable isotope analysis. We captured 20 shrews from three streams in Aomori Prefecture from 2013 to 2016 barring snow accumulation seasons. The digestive contents analysis showed that water shrews mainly fed on aquatic insects, whereas freshwater crabs, fishes, and terrestrial insects were also observed as diets. δ¹³C values from the stable isotope analysis were not significantly different between muscles and body hair and indicated a primary diet of aquatic invertebrates and fishes. δ¹⁵N values were significantly lower in muscles and indicated a similar trophic position of water shrews to fishes. In the isotope mixing model, the contribution of terrestrial invertebrates was less than 0.35 except for two individuals that showed the highest terrestrial invertebrate ratio (> 0.5) and the lowest aquatic invertebrate ratio. This study also demonstrated that body hair from any part of the back was sufficiently useful for dietary stable isotope analysis.

The sequence variation of the mtDNA control region (CR) was analyzed for the two sibling species of Myodes (the gray-sided vole M. rufocanus and the dark red-backed vole M. rex) in Hokkaido mainland and its adjacent islands of Japan. The evolutionary rate of the CR was estimated using the island–island connections during the Quaternary. The 737–741-bp were determined for 1196 individuals of M. rufocanus from 65 localities and 315 individuals of M. rex from 26 localities. The CR was highly variable in both species: 330 and 79 haplotypes were identified for M. rufocanus and M. rex, respectively. The genetic distances were estimated for six island population pairs of M. rufocanus and two pairs of M. rex. The genetic distances log-linearly increased with an increase in the separation time. Although the evolutionary rates (substitutions/site/Myr) varied around 10 000 years ago, they became less variable further back in time. The representative evolutionary rate was estimated at 0.196/Myr with 0.139–0.254 (95% CI) for M. rufocanus 40 000 years ago and 0.101/Myr with 0.068–0.134 (95% CI) for M. rex 120 000 years ago. These estimates open opportunities for comparative studies on the evolutionary history of the sibling species.

The jumping ability of Reeves's muntjacs (Muntiacus reevesi) was experimentally determined and verified in a captive environment using seven male animals. The experiment found that the maximum height that Reeves's muntjac could jump over was 80 cm. Against an obstacle of 45 cm or more, the latency to jump and the time spent on exploratory behavior were longer relative to lower obstacles. Based on this result, net fences with a height of 85 cm were installed at three sites in Isumi City, Chiba Prefecture, Japan, and bait was installed inside the fence to verify its intrusion prevention effect. For over a month, even in winter when food resources are scarce, the muntjacs did not jump over the fence to reach the bait. However, during the first week of the test session, physical contact such as pressing the head and nose against the fence was observed, and exploratory behavior was concentrated on the base of the fence. These results suggested that a high intrusion prevention effect could be obtained by installing a fence with a height of 85 cm and securing the fence hem with piles.

The Persian leopard (Panthera pardus saxicolor) is an endangered species widely distributed across Iran. Rough estimates indicate 550–850 Persian leopard individuals inhabit the country, which comprises more than two thirds of its global population. Population monitoring of this large carnivore in Iran is one of the main objectives of current conservation planning. Therefore, adopting a more diversified methodology to achieve reliable, cost-effective, and pragmatic measures is urgently needed. We conducted a study for individual identification of the Persian leopard in Parvar Protected Area via fecal sampling and molecular tools and attempted to test the feasibility of this approach. We used 12 previously reported polymorphic microsatellite loci, of which only five were qualified for genotyping analysis. Finally, nine leopard individuals were identified. We measured the ability of the five loci in distinguishing individuals by P (ID)sib. The cumulative observed probability of identity and probability of identity for sibling individuals were estimated to be 0.005 and 0.05, respectively. Data presented on spatial distribution of leopards in this study could help better understand the behavioral ecology and conservation biology of the species. Moreover, our findings will assist future research in developing methodologies for large-scale studies and providing data for effective wildlife conservation.

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.