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.

Ecological Specialisation and Evolutionary Reticulation in Extant Hyaenidae

During the Miocene, Hyaenidae was a highly diverse family of Carnivora that has since been severely reduced to four species; the bone-cracking spotted, striped, and brown hyenas, and the specialised insectivorous aardwolf. Previous studies investigated the evolutionary histories of the spotted and brown hyenas, but little is known about the remaining two species. Moreover, the genomic underpinnings of scavenging and insectivory, defining traits of the extant species, remain elusive. Here, we generated an aardwolf genome and analysed it together with the other three species to reveal their evolutionary relationships, genomic underpinnings of their scavenging and insectivorous lifestyles, and their respective genetic diversities and demographic histories. High levels of phylogenetic discordance suggest gene flow between the aardwolf lineage and the ancestral brown/striped hyena lineage. Genes related to immunity and digestion in the bone-cracking hyenas and craniofacial development in the aardwolf showed the strongest signals of selection, suggesting putative key adaptations to carrion and termite feeding, respectively. A family-wide expansion in olfactory receptor genes suggests an acute sense of smell was a key early adaptation. Finally, we report very low levels of genetic diversity within the brown and striped hyenas despite no signs of inbreeding, putatively linked to their similarly slow decline in Ne over the last ∼2 million years. High levels of genetic diversity and more stable population sizes through time are seen in the spotted hyena and aardwolf. Taken together, our findings highlight how ecological specialisation can impact the evolutionary history, demographics, and adaptive genetic changes of an evolutionary lineage.

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.

Considerations on Two Cruces Philologorum (Ael. NA 15, 15)

The present article aims to elucidate an interesting narrative that forms a portion of Aelian’s paradoxographic work Περὶ ζῴων ἰδιότητος (On the Characteristics of Animals, Lat. De natura animalium). The passage under discussion describes some horned animals of oriental origin that were involved in the annual fighting contests during a one-day competition held on the initiative of a “great king of India” — probably Chandragupta (4th–3rd c. BC), the founder of the Maurya dynasty. Aelian’s chapter (NA 15, 15) was perhaps taken from Megasthenes’s Ἰνδικά (Description of India). The passage includes two hapax legomena referring to two species of animals: †μέσοι† and †ὕαιναι†. The first of these should be identified with the Ladakh urial (Ovis orientalis vignei Blyth); cf. Prasun məṣé ‘ram, urial’ (< Vedic mēṣá- m. ‘ram’). Aelian’s exact description of the horned animals called †ὕαιναι† clearly demonstrates that the alleged “striped hyena” (Gk. ὕαινα) must represent the chinkara, i. e., the Indian gazelle (Gazella bennettii Sykes). The Indo-Aryan term for ‘chinkara’ (Ved. hariṇá- m ‘Indian gazelle’, hariṇī́- f. ‘female gazelle’; cf. Pa. and Pk. hariṇa- m., hariṇī- f.) suggests that the corrupted form in Aelian’s passage should be emended as ὑάριναι [hyárinai]. This seems a near-optimal adaptation of the Pali or Prakrit appellative háriṇā pl. ‘chinkaras’.

Ecological specialisation and evolutionary reticulation in extant Hyaenidae

During the Miocene, Hyaenidae was a highly diverse family of Carnivora that has since been severely reduced to four extant genera, each of which contains only a single species. These species include the bone-cracking spotted, striped, and brown hyenas, and the specialised insectivorous aardwolf. Previous genome studies have analysed the evolutionary histories of the spotted and brown hyenas, but little is known about the remaining two species. Moreover, the genomic underpinnings of scavenging and insectivory, defining traits of the extant species, remain elusive. To tackle these questions, we generated an aardwolf genome and analysed it together with those from the other three species. We provide new insights into the evolutionary relationships between the species, the genomic underpinnings of their scavenging and insectivorous lifestyles, and their respective genetic diversities and demographic histories. High levels of phylogenetic discordance within the family suggest gene flow between the aardwolf lineage and the ancestral brown/striped hyena lineage. Genes related to immunity and digestion in the bone-cracking hyenas and craniofacial development in the aardwolf showed the strongest signals of selection in their respective lineages, suggesting putative key adaptations to carrion or termite feeding. We also found a family-wide expansion in olfactory receptor genes suggesting that an acute sense of smell was a key early adaptation for the Hyaenidae family. Finally, we report very low levels of genetic diversity within the brown and striped hyenas despite no signs of inbreeding, which we putatively link to their similarly slow decline in Neover the last ∼2 million years. We found much higher levels of genetic diversity in both the spotted hyena and aardwolf and more stable population sizes through time. Taken together, these findings highlight how ecological specialisation can impact the evolutionary history, demographics, and adaptive genetic changes of a lineage.