A new study by Russian and American scientists has shed some light on how the lumber industry is impacting a reclusive fanged deer in the sprawling – and increasingly exploited – forests of the Russian Far East.
The Siberian musk deer is a small and retiring creature of deep conifer woods, a ghost of understory thickets and shadows. Despite the diminutive stature and under-the-radar habits, it's quite the looker in its own way: the cute, half-hunched little beasts "can look more like kangaroos than deer" at first glance, writes Jonathan Slaght, the Wildlife Conservation Society's Russia and Northeast Asia Coordinator.
If you just zoomed in on the dentition, though, thoughts of sabertooths or walruses might come to mind. That's because male musk deer brandish fang-like canines that may be four inches long – possibly the fighting weaponry this primitive, antler-less deer employs for the rut.
Their name, meanwhile, stems from the bucks' other characteristic feature: an abdominal gland (the "musk-pod") producing a pungent pheromone that probably both attracts mates and serves as a territorial calling card.
The musk of the tusked musk deer (new tongue-twister for you – you're welcome) may serve bucks well, but it's also been a source of woe. A hot item in both traditional medicine and perfumery (by weight, it's worth more than gold), the coveted substance is the prime reason for the decline of the species at the hands of humans.
Musk harvest can exact a heavy toll since a buck produces only about 25 grams of the stuff. There's also the significant issue of bycatch: along with the full-grown, musk-brewing bucks hunters are actually after, snares also kill does and subadults, Slaght explains.
In the Russian Far East's heavily timbered Sikhote-Alin Mountains, that demand for musk deer takes place in the context of a vigorous logging industry. Slaght and several collaborators set out to explore how lumbering and its associated impacts might influence the distribution of Siberian musk deer in the central part of the range, in the province of Primorsky Krai (also known as Primorye).
It's not news that many forest mammals seem to retreat in the face of logging and road-building, but it's not always clear exactly why. And knowing why doesn't just help conservationists better protect such species – it also suggests ways to make timber-harvesting more sustainable.
In Primorye, musk deer favour mid-elevation coniferous forests dominated by Ayan spruce, Manchurian fir and Korean pine. Diet mainly explains their preference for these evergreen woods: the animals munch lichens year-round, and especially in winter. Their favourite tree-growing (or epiphytic) lichens flourish on the trunks and branches of big conifers.
Older forests make better deer habitat, partly because lichens prosper in such ecosystems, with open-crowned, heavy-branched trees providing lots of light, moisture and footholds for an epiphytic way of life. Musk deer can browse up to a level of about 1.2 metres (roughly four feet), which puts the lichen crop of low-hanging branches and understory saplings within reach – not to mention toppled, lichen-swathed boughs and logs, the sort of deadwood that's plentiful in old forests. Beyond the food they provide, the complex structure of these woods, with all their deadfall and shrubbery, gives the furtive musk deer plenty of hiding places.
Unfortunately, timber companies covet the very same conifer forests for their commercially valuable spruce and larch (and to a lesser extent fir). To gauge how this logging affects the toothy deer and their habitat, the researchers surveyed for deer abundance as well as lichen load in three regions along the northern border of the Sikhote-Alin Biosphere Reserve.
The findings? Unsurprisingly, musk deer in the region favoured areas with plentiful lichen that were farthest from main roads and logged tracts. "In other words, the more inaccessible an area, the greater the likelihood that musk deer will be present," the authors wrote in a new paper published in the journal Oryx.
Hunters and poachers – for there is both legal and illegal musk-deer harvesting going on in the region – can use logging roads and skid trails (made where logs are hauled out of the woods) to penetrate the forest.
"The access issue is a big one," Slaght said in an email. An earlier analysis by WCS showed that the total length of forest roads in Primorye's Ternei County, one of two adjoining counties where this new research took place, increased from 228 kilometres (142 miles) in 1984 to 6,278 kilometres (3,900 miles) in 2014.
"These are almost all logging roads, which give people, including poachers, much easier access to the forests," Slaght said.
Poaching is a significant issue in the region, and though Slaght doesn't know the exact rate, the dramatically expanded road network suggests its potential magnitude: if poachers and hunters are willing to walk up to five kilometres (three miles) off a road, Slaght reckoned, as much as 60 percent of Ternei County is now accessible to them.
Musk deer can find temporarily rich lichen pickings among logging slash, the woody debris generated during logging operations (in fact, some evidence suggests the crash of a toppling tree may actually draw the deer). And this is not lost on hunters. "Poachers drive to freshly logged areas and set snares there for musk deer," Dasha Maksimova, a Pacific Geographical Institute graduate student who conducted fieldwork for this study, said in a WCS press release.
Slaght and his colleagues note that the relationship between logging, lichen and musk deer isn't completely clear-cut (pardon the pun). In certain cases, tree-cutting may not degrade lichen load; in fact, surveys in some selectively harvested tracts showed luxuriant dangles of epiphytic lichens hanging from the canopies of big trees facing logging tracks, perhaps a reflection of increased sunlight.
"Lightly logged spruce-fir forests could become more suitable for Usnea lichens if the largest trees with largest branches remain and get more sunlight and growing spaces," said the World Wildlife Fund's Brian Milakovsky, one of Slaght's co-authors on the paper. "Otherwise, logging is usually going to be negative."
But the researchers also note some encouraging takeaways from their analysis. Closing roads following logging, for one thing, may be a simple measure to provide musk deer more safe havens – and protect other animals vulnerable to poaching, from salmon to Amur tigers.
A timber company may reap its own rewards from decommissioning roads, the researchers point out: namely the possibility of reduced rates of illegal logging and human-caused fires. "Road closures are mutually beneficial because they protect wildlife and also reduce illegal harvest of timber," Slaght said.
The biggest logging company in the study region, Joint Stock Company TerneyLes, has shown a willingness to accommodate some conservation objectives: for example, closing off some logging roads in riparian forests important to tigers, Blakiston's fish owls and other sensitive species. Slaght said TerneyLes is "open to the idea" of implementing similar measures to protect conifer refuges for musk deer.
Meanwhile, for insight into the occasional high drama spicing up musk-deer fieldwork in the Russian Far East, check out this blog post by Slaght, where he recounts a hair-raising encounter while tracking a radio-tagged deer. Needless to say, the encounter was not with the target species.
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Slaght et al's Oryx paper on this research – "Anthropogenic influences on the distribution of a Vulnerable coniferous forest specialist: habitat selection by the Siberian musk deer Moschus moschiferus" – can for a limited time be downloaded for free here.
Top header image: Lesa Luga/Flickr
Human Impact
Conservation
Animal Behaviour
