Geraldine Werhahn is a research associate at Oxford University. She is a conversation biologist who uses a multidisciplinary approach to study the ecology and evolution of carnivores in the Himalayas and the Tibetan Plateau. Geraldine shares her recent work on the taxonomy and adaptive evolution of the Himalayan wolf.
Geraldine in the Himalayas, collecting wolf scat for population genetic analyses (Photo credit: Naresh Kusi).
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Institute. Wildlife Conservation Research Unit (WildCRU), Department of Zoology, Oxford University, UK
Academic life stage. Research associate.
Research themes and interests. My research focuses on the conservation and ecology of carnivores in the high-altitude ecosystems of the Himalayas and the Tibetan Plateau of Asia. My work is driven by the need to maintain healthy carnivore populations and conserving ecosystem integrity. I take a multidisciplinary research approach (from genetics, to ecology, to social science) to understand my study system and develop science-based conservation strategies.
Current study system. My current study system is the Himalayan wolves and coexisting carnivores in the high altitudes of Asia. These high-altitude ecosystems are vast wilderness regions, also sometimes called the third pole, where the harsh climate and low oxygen levels shape a unique fauna and flora. The Himalayan wolf is found in habitats above 4000 m elevation and is unique to the Himalayas and the Tibetan Plateau. As a top predator alongside the Snow leopard it plays an important role in ecosystem function, warranting its conservation.
A Himalayan wolf pup in the Transhimalayas of Nepal (Photo credit: Geraldine Werhahn).
A herd of Kiang (Equus kiang) in the Transhimalayas of Nepal. These wild equines share their habitat with the Himalayan wolf (Photo credit: Geraldine Werhahn).
Recent paper in Journal of Biogeography. Werhahn et al. (2020) Himalayan wolf distribution and admixture based on multiple genetic markers. Journal of Biogeography. 47(6): 1272–1285. https://doi.org/10.1111/jbi.13824
Motivation for this recent paper. The motivation for this research was to investigate the genetics and ecology of the Himalayan wolf to inform its pending taxonomic classification and advance its conservation. Prior to our work, little research had been conducted on the Himalayan wolf. Most data were derived from captive animals at zoological gardens, or from museum collections, and a range of different names were used for this one wolf lineage across different publications. We focused especially on the evolutionary history, foraging ecology, and distribution of the Himalayan wolf. We wanted to determine if the Himalayan wolf was a distinct lineage that occurs alongside the Holarctic grey wolf, and to explore its phylogeny in relation to contemporary canids from around the globe. For conservation purposes, we also investigated whether hybridization occurs between the Himalayan wolf, the grey wolf, and domestic dogs.
Key methodologies. We developed a conservation genetics toolkit specifically tailored for non-invasive scat sampling of the Himalayan wolf. Our work was conducted in close collaboration with our genetics partner, the RZSS WildGenes lab in Edinburgh. We worked with non-invasive samples obtained from scat. Thereby we could cover many packs and individuals without interfering with the animals. Our methods allowed us to identify wolf individuals and determine their phylogenetic relationship with other canids. We also searched for genetic differences at functional genes known to be involved in adaptation to low environmental oxygen levels. Such genetic adaptations to low oxygen have been described for Tibetan mastiff dogs (the typical dog breed of the Tibetan Plateau) and human populations on the Plateau. So, we were interested to investigate if such adaptations might be important in the ecology of the Himalayan wolf. We analysed 280 wolf scat samples collected from the Tibetan Plateau in western China, and the Central Asian mountains in Kyrgyzstan and Tajikistan, and we included canid reference sequences from around the globe to build the phylogenies based on mitochondrial DNA sequences.
Major results. The Himalayan wolf forms a genetic clade that is distinct from other canids based on the tested mitochondrial and nuclear markers. We found consistent differentiation and unique alleles in the Himalayan wolf samples at functional genes known to be involved in adaptation to low oxygen levels (the hypoxia pathway).
The distinctness of the Himalayan wolf may be related to the uplifting of the Himalayas and the Tibetan Plateau that produced a unique ecological niche in the high altitudes to be filled. Our preliminary research suggests that hybridisation is limited between the Himalayan wolf and the Holarctic grey wolf.
We hypothesise that the Himalayan wolf has a fitness benefit over the Holarctic grey wolf in the high altitudes due to its hypoxia adaptation. Our paper concludes that the Himalayan wolf merits taxonomic recognition and designation as an Evolutionary Significant Unit (ESU). Establishing the Himalayan wolf as an ESU will allow for the much-needed conservation to advance on the ground while the taxonomy is being conclusively decided on.
Geraldine observing a young wolf family from afar (Photo credit: Naresh Kusi).
Major challenges. Finding elusive carnivores like wolves in remote and harsh high-altitude habitats is challenging. Wolves inhabit large territories and leave few signs, usually in form of scats at characteristic landscape features, such as ridgelines and crossing points. Hence as researchers trying to find wolves in such vast landscapes we had to learn to read and navigate the valleys and mountains like a wolf pack does. With enough territory covered our team managed to collect substantial data of multiple wolf packs across the different study regions. We could provide a first estimation of the distribution range based on our landscape scale data and found that the Himalayan wolf is more widely distributed than previously thought: this wolf is found across the Himalayas and the Tibetan Plateau, which present a continuous high-altitude ecosystem. The distribution appears to be influenced by elevation, presumably in connection to its genetic adaptation to cope with the low oxygen levels in these high altitudes.
Pack mules, used for transporting scientific gear and equipment, grazing in the evening light on fresh grasses (a welcome nutritious forage for them after the long exhaustive weeks of expedition). Buddhist stupas in the background are characteristic landmarks of worship of the region (Photo credit: Geraldine Werhahn).
Net steps. Our team is now working on piloting conservation action in close collaboration with Himalayan mountain communities to mitigate human-carnivore conflict. The goal is to facilitate a long-term sustainable coexistence of humans and carnivores in these vast, pristine high-altitude habitats. We continue to monitor wolf populations in our study area and are collecting more ecological and behavioural data.
An important question is how many Himalayan wolves exist in wild populations today. Our study provides a first estimate of the population range. But a thorough understanding of their distribution on regional level is required to advance conservation of this species because hunting pressure seems high due to human-wildlife conflict and illegal wildlife trade.
If you could study any organism on Earth, what would it be? It would be canids, especially wolves, followed by snails. I have a profound interest for canids due to their complex social behaviour, their role in trophic cascades and importance in ecosystem functioning, their intelligence, and skilful adaptation to live in remarkably diverse habitats from urban spaces to high mountains and deserts. I would also be interested to study snails, for their immense diversity and occurrence in very diverse habitats and because I find the aesthetics of their “houses” fascinating. They are remarkable in their capability to seemingly disappear when conditions are unfavourable and then reappear in large numbers when conditions improve.
An adult Himalayan wolf watching over the valley below. Looking for his mates or potential prey? (Photo credit: Geraldine Werhahn)
Anything else? This research would not have been possible without a dedicated team that has become my family on the long expeditions. We discovered many new insights around other mammals besides the wolves, birds and plants during these expeditions. For example, my team rediscovered the charismatic wild yak for Nepal during one of our expeditions. This was breaking news for the country of Nepal and eventually our team’s photograph of the wild yak ended up on the Nepalese 5-rupee bill.