The pangolin puzzle: scratching the surface
The pangolin may represent one of the biggest challenges the conservation world currently faces. Exploited for their meat and scales, growing demand has crippled most viable populations in the wild, with the only limiting factor in the centuries-old pangolin trade being their increasing scarcity. As some of the lesser-known species to science, pangolins have largely gone under the radar; that is until 2016 when all eight extant species were re-classified from Appendix II to Appendix I, the highest level of protection under CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora). CITES is an international agreement between governments who’s aim is to ensure that international trade in specimens of wild animals and plants does not threaten their survival. For all those years before that, the pangolin was quietly and unassumingly being hunted and traded into extinction. The four decades prior to the CITES amendment saw a 150% increase in the number of pangolins hunted, with some species losing up to 90% of individuals. Since 2000, more than one million pangolins have been traded, giving them the regrettable title of the world’s most trafficked wild mammal. Despite hard-hitting conservation efforts and thorough scientific research, we still know very little about any of the eight species – a gaping hole that must be filled if the pangolin is to survive the decades to come.
A unique ecology
So, what do we know about this scaly mammalian cousin of ours? Found across Africa and Asia, you could be forgiven in mistaking a pangolin for some otherworldly anteater-armadillo hybrid, or perhaps an artichoke with legs. Really, they are far more unique than that, giving taxonomists an all too familiar headache when it comes to naming and grouping them; they settled on defining an entirely new order for the pangolin – Pholidota – comprised only of the eight known species. The pangolin lives a nocturnal and solitary life, only finding the company of others when mating or caring for their young, who cling to their mother’s tail on foraging trips away from the nest. The nests are built in excavated burrows, conspicuously pangolin-made due to their uniquely round entrances – of which there are several, sealed with loose earth to prevent predators and other unwanted visitors from intruding. Burrows can be more than 5m deep and are important in finding solace from the searing midday heat, as temperature regulation is not a strong suit for pangolins. Their prey consists primarily of ants and termites – for the crossword fanatics amongst you, this makes them both myrmecophagous and termitophagous. Pangolins are remarkably well-adapted for this feeding behaviour. They possess a fly tape-like tongue as long as their body (attached to their pelvis, of course) and special muscles that seal the nostrils and ears shut when digging through soil to reach insect colonies. On average, an adult pangolin will consume some 70 million ants annually, leaving no doubt as to why the pangolin is referred to as Nature’s own pest control service.
Pangolins are nature’s pest control
Maize production is a considerable source of food and income across Africa and Asia, most notably in South Africa and China, and pangolins may play an important role in preventing mass crop damage. With few, if any, effective control methods available to farmers, termite populations left unchecked are the major constraint to increasing yields of maize; in Africa, 20-30% of preharvest loss is due to termites. By preying heavily on termites, pangolins influence their abundance and community structure in a way that minimizes these losses and thereby appear to be unlikely contributors to the agricultural economy of both continents.
Moreover, in Taiwan, the Chinese pangolin feeds primarily on yellow crazy ants, an invasive species in the region, and so are critical in maintaining local ecosystem function and biodiversity – invasive species are one of the “Evil Quartet” responsible for extinctions, along with habitat degradation, pollution, and over-harvesting.
Pangolins as bioturbators
It is likely that pangolins also influence a number of soil process through their excavation and use of burrows. Acting as bioturbators – organisms that rearrange and aerate soils – they contribute to soil mixing and create preferential flow paths for infiltrating water. In this way, they could also be defined as ecosystem engineers because they alter the physical environment around them, and their burrows can be used by a range of commensal organisms. Pangolins are clearly of more use to communities as pest control and bioturbators than as a source of trade.
A challenge for conservation
Pangolin conservation has proven to be a difficult and sometimes futile task. The lack of research and data on population trends and sizes, reproductive potential, and their natural history is a hindrance in their protection, muddying the waters when it comes to discerning the specific conservation needs of different pangolin species and populations. Tracking trade data is also an arduous task due to the alternative supply chains in Africa. For example, hunters in Ghana often trade to wholesalers away from the bushmeat markets, whilst in Gabon, Asian industry workers will buy directly from the hunters. However, this is not simply a case preventing the illegal hunting of and trade in pangolins and their derivatives, we really have no clue as to the extent of damage already done to populations. Their nocturnal and secretive nature makes them extremely hard to study and gather population estimates from, and seizures almost certainly represent a small fraction of the pangolins actually being traded. Alas, it is undoubtful that populations are decreasing across both Africa and Asia. More often than not conservation will intervene through captive breeding programs in order to reverse these declines, however, pangolins show poor acclimatization to captive environments; over the last 150 years more than 100 zoos or organisations have attempted to maintain pangolins, yet most have died within 6 months and breeding programs have been largely unsuccessful.
Why we should protect pangolins
You may question how we know that pangolin populations are decreasing, without already having concrete population data. The hunting of pangolins, as it is currently, is not sustainable; the fact that 45% of individuals found in wild meat markets in west Africa were juveniles or subadults is a strong indicator of overexploitation. More definitive than that, all eight pangolin species show the tell-tale signs of a species at risk of extinction: low reproductive rates, poor breeding and longevity in captivity, fragmented populations, high demand for their meat and derivatives, and continuous habitat degradation. The use of pangolins for their meat and scales does not take priority over their existence. Pangolin scales hold no known medicinal properties, they make terrible pets, and much like their morphological brethren the artichoke, I doubt the meat is worth the effort.
Written by: Linus Hiscox, studying MSc Global Biodiversity Health and Conservation at University of Bristol and DSWF Programmes and Policy Intern.