Status, Distribution, and Threats of Striped Hyena (Hyaena hyaena Linnaeus, 1758) in Nepal: A Review

Striped hyena (Hyaena hyaena) is a member of the Hyaenidae family distributed globally from Africa to Central Tanzania, the Arabian Peninsula, Turkey, Central Asia, and the Indian subcontinent including Nepal. Only a few documented studies have been carried out at a national as well as international level regarding their habit, habitat, threats, and conservation measures. Various open access works of literature including articles, reports, and books published from 1941 to 2021 were assessed through Google scholar and Research gate for this study. We searched, refined, and selected 42 pieces of literature for the study purpose. We found that striped hyenas were recorded from five national parks of lowland Terai regions and they were recorded in six districts lying outside the protected area in Central and Western Terai as well as the hilly region of Nepal. Habitat degradation, decreased prey population, retaliatory killing by poisoning, poaching and road kills are found to be the major threats to these endangered scavengers that require immediate conservation initiatives We believe that this manuscript can fulfill the knowledge gap on this species and suggests conservation initiatives, which could be a landmark for conducting further research and conservation of striped hyenas.

The faded stripes of Bengal: a historical perspective on the easternmost distribution of the striped hyena

The striped hyena (Hyaena hyaena) is an understudied large carnivore with no known historic range map. Knowledge of the past and present extent of its easternmost distribution beyond 85° east longitude is dubious. Through a comprehensive review of historical evidence and contemporary records, we investigated striped hyena presence in Bengal, i.e., Bangladesh and the Indian state of West Bengal in South Asia. We found 14 historical records, with the oldest one dating to 1876. Our review establishes Bangladesh as a former striped hyena range country and the striped hyena as one of the first large carnivores to go extinct in Bangladesh. We identified northern Bangladesh as part of its historical range (until ~1965), and south-central Bangladesh as a possible part of its historical range. In West Bengal, India, hyenas were historically present up to the southern tributaries of the Brahmaputra River, but the present range is reduced. The area south of the Damodar River is its last refuge in Bengal. We also found 15 contemporary records (2010–2021) in Bengal, from sites situated on the eastern limit of the Chota Nagpur Plateau. These records noted 25 sightings including 9 deaths due to poaching, train accidents, and retaliatory killings. Our review demonstrates that hyenas are currently present up to 87° east longitude, which extends the currently documented easternmost range for the species by almost 1,000 km. We recommend methods which can be applied to delineate the historical extent of striped hyenas elsewhere as well as for other poorly understood species.

Taphonomy of an excavated striped hyena (Hyaena hyaena) den in Arabia: implications for paleoecology and prehistory

Studies of modern carnivore accumulations of bone (i.e., neo-taphonomy) are crucial for interpreting fossil accumulations in the archaeological and paleontological records. Yet, studies in arid regions have been limited in both number and detailed taphonomic data, prohibiting our understanding of carnivore bone-accumulating and -modifying behavior in dry regions. Here, we present a taphonomic analysis of an impressive carnivore-accumulated bone assemblage from the Umm Jirsan lava tube in the Harrat Khaybar region, Saudi Arabia. The size and composition of the bone accumulation, as well as the presence of hyena skeletal remains and coprolites, suggest that the assemblage was primarily accumulated by striped hyena (Hyaena hyaena). Our findings (1) identify potentially useful criteria for distinguishing between accumulations generated by different species of hyenas; (2) emphasize the need for neo-taphonomic studies for capturing the full variation in carnivore bone-accumulating and modifying behavior; (3) suggest that under the right settings, striped hyena accumulations can serve as good proxies for (paleo)ecology and livestock practices; and (4) highlight the potential for future research at Umm Jirsan, as well as at the numerous nearby lava tube systems. We encourage continued neo-taphonomic efforts in regions important in human prehistory, particularly in arid zones, which have received little research attention.

Phylogenetic Analysis of Striped Hyaena (Hyaena hyaena: Hyaenidae, Carnivora) in Hatay Province in Turkey

Striped hyaena (Hyaena hyaena) is one of the species in danger of extinction and categorized globally as “Under Threatened Organism”. From time to time, different tissue samples and carcasses of the striped hyena are reported in different regions of Anatolia. In this study, 571 bp length of Cytochrome C Oxidase Subunit II (COX 2) of mitochondiral DNA from hair, ears, nails and teeth specimens from six striped hyaenas were amplified and sequenced to determined phylogenetic relationships between close and distant species related to hyaena. Tissue samples using in this study were found randomly at different times in Hatay province, Turkey. According to our results, all colected samples located in Hatay region are the members of H. hyaena species. Moreover, this research is the first molecular research using COX2 gene region for phylogenetic analysis in Turkey. Further investigation can be performed on studies that suggest determining phylogenetic status of striped hyaenas.

Changes in the large carnivore community structure of the Judean Desert in connection to Holocene human settlement dynamics

Investigating historical anthropogenic impacts on faunal communities is key to understanding present patterns of biodiversity and holds important implications for conservation biology. While several studies have demonstrated the human role in the extinction of large herbivores, effective methods to study human interference on large carnivores in the past are limited by the small number of carnivoran remains in the paleozoological record. Here, we integrate a systematic paleozoological survey of biogenic cave assemblages with the archaeological and paleoenvironmental records of the Judean Desert, to reveal historical changes in the large carnivore community. Our results show a late Holocene (~ 3400 years ago) faunal reassembly characterized by the diminishment of the dominant large carnivoran, the Arabian leopard (Panthera pardus sbsp. nimr), and the spread of the Syrian striped hyena (Hyaena hyaena sbsp. syriaca). We suggest that increased hunting pressure in combination with regional aridification were responsible for the decrease in the number of leopards, while the introduction of domestic animals and settlement refuse brought new scavenging opportunities for hyenas. The recent extirpation of leopards from the region has been a final note to the Holocene human impact on the ecosystem.

Canines and carnassials as indicators of sociality in durophagous hyaenids: analyzing the past to understand the present

We analyzed the lower and upper dentition of the family Hyaenidae along its evolutionary history from a multivariate point of view. A total of 13,103 individual measurements of the lengths and widths of canines and the main post-canine teeth (lower third and fourth premolar, lower first molar, and upper second, third, and fourth premolars) were collected for 39 extinct and extant species of this family. We analyzed these measurements using principal component analyses. The multivariate structure characterized the main groups of previously defined hyaenid ecomorphs. Strikingly, our analyses also detected differences between social hunting durophages (such as Crocuta crocuta) and solitary scavengers (such as Hyaena hyaena or Parahyaena brunnea). Concerning the hyaenid bauplan, social hunters have large carnassials and smaller canines, whereas solitary scavengers show the exact opposite morphological adaptations. Additionally, scavengers exhibited upper canines larger than lower ones, whereas hunters have upper and lower canines of similar size. It is hypothesized that sociality has led to an increase in carnassial length for hunting durophages via scramble competition at feeding. Such competition also penalizes adults from bringing food to cubs, which are consequently breastfed. On the other hand, it is also hypothesized that natural selection has led to solitary scavengers having large canines to transport carcasses to cubs. Our results indicate that these functional aspects are also better reflected by lower teeth than the upper dentition, which leads to a mosaic evolution.

Predicting the potential distribution of striped hyena Hyaena hyaena in Iran

Predictive potential distribution modelling is crucial in outlining habitat usage and establishing conservation management priorities. Association among species occurrence and environmental and spatial characteristics has been calculated with species distribution models. Herein, we used maximum entropy distribution modelling (MaxEnt) for predicting the potential distribution of striped hyena Hyaena hyaena in the entire country of Iran, using a number of occurrence records (i.e., 118) and environmental variables derived from remote sensing. The MaxEnt model showed a high rate of success according to AUC test scores (0.97). Our results are roughly congruent with previous studies suggesting that mountainous re-gions in northern and western Iran, and the plains in central and eastern Iran are a suitable habitat for H. hyaena.