How will climate change affect Arctic caribou and reindeer? - Phys.org
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How will climate change affect Arctic
caribou and reindeer?
1 December 2017, by Conor Mallory
languages across the world, such as tuktu in
Inuktitut.)
A complicated problem
Just how this iconic Arctic species will be affected
in a warming climate remains unclear.
Current predictions suggest that the climate will
continue to change for decades into the future,
regardless of the mitigation actions we take.
Barren-ground caribou in autumn near Kugluktuk, Caribou and reindeer have tremendous
Nuanvut. Credit: Mathieu Dumond/Umingmak socioeconomic value in the north, and if we want to
Productions maintain sustainable caribou harvesting and
husbandry in the future, we must understand how
they will respond to environmental change.
This spring, I spent close to two weeks flying over My colleagues and I reviewed hundreds of scientific
central Nunavut, peering out the window of a small papers that studied caribou and reindeer from
plane at the rolling tundra below, looking for and Alaska to Nunavut to Russia. By the end, we
counting caribou to monitor their numbers. produced a complete picture of how climate change
may affect the caribou and reindeer species, based
The Qamanirjuaq barren-ground herd were arriving on current knowledge.
on their tundra calving grounds to give birth after
migrating from winter ranges in the boreal forest. We found that it's challenging to make general
At times caribou dotted the landscape all the way predictions. The species has a circumpolar
to the horizon. distribution and inhabits a variety of ecosystems,
both similar and distinct. How different populations
The terrain here is relatively pristine. There are few will respond to varying effects of climate change in
communities or developments. Due to the this diverse range of systems is complex.
remoteness of the herd's habitat, it is, in some
ways, hard to imagine that human Summer effects
activities—whether climate change or industrial
disturbance—could ever be of much concern to In many regions, climate change is causing longer
them. and warmer summers. In the context of caribou,
which live in colder regions, this typically means
And yet, we know that human activity and longer growing seasons and better access to
disturbance provide the most imminent threat to nutritious plants throughout the summer months.
the persistence of many caribou and reindeer
populations. (Reindeer and caribou are the same But plants are not the only part of the ecosystem
species, Rangifer tarandus, but have different affected by longer and warmer summers.
English names in North America and Eurasia. Of
course, the species has many names in different Parasitic flies, particularly warble flies and botflies,
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torment caribou during the summer months. These more calf deaths.
insects aren't just looking for blood like mosquitoes
and black flies—they're trying to lay their eggs on a Winter effects
caribou's skin or in its nose.
Winter warming produces similarly complex
As you can likely imagine, caribou want no part of effects.
this. They will spend hours running to escape these
parasites, which means they spend less time Climate change is predicted to increase the
feeding. frequency of winter icing. Icing is usually caused by
rain-on-snow or thaw-freeze events, and presents a
For a given region or herd, will increased plant real problem for caribou.
growth or increase insect harassment have more of
an effect on caribou? During the winter caribou dig in the snow to get to
food underneath. Icing events trap food beneath an
impenetrable layer of ice. These events have led to
mass starvation of Arctic caribou and reindeer in
the past.
On the other hand, longer autumns and earlier
springs shorten the winter period of food scarcity.
This should benefit caribou, but the net effect will
depend on the balance of these changes in a given
region.
These are just some of the wide-ranging potential
implications of climate change for Arctic caribou
and reindeer. They may also shift their ranges
northward and alter their migratory behaviour in
response to climate change, or begin sharing their
lands with new or increased competitor species
Svalbard reindeer are the smallest subspecies of such as moose and white-tailed deer.
reindeer. Credit: Per Harald Olsen/Wikimedia
Importance of caribou and reindeer
Caribou and reindeer provide incredible value
We're already seeing some of these effects play throughout the circumpolar world. In ecological
out. terms, they are the most abundant large terrestrial
herbivore. They have important grazing effects on
In Svalbard, Norway, warmer summers have been plant communities and support predator
generally positive for caribou, as better plant growth populations.
has led to heavier animals in the fall. But in Arctic
North America, more green growth has been The ecological importance of caribou means that
associated with declines in caribou populations, changes to caribou and reindeer populations affect
possibly due to the northward expansion of less many other organisms, including wolves, Arctic
nutritious shrubs. shrubs and lichens.
Research has shown that insects have been They also have huge socioeconomic value. One
trouble for caribou in Arctic Finland. There, warmer report conservatively suggests that three herds in
weather brought more insects that harassed northern Canada provide the equivalent of $20
caribou calves, which led to less weight gain and million dollars annually in food alone. Semi-
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domesticated reindeer similarly contribute huge
value to those who herd them, including the Saami
people of Finland, Russia, Norway and Sweden.
If there is a silver lining to this, it's that we know
caribou and reindeer live in a wide variety of
environments and ecosystems—and this may
provide them with some resilience.
But we don't know if their ability to adapt is
sufficiently agile to respond to the ongoing rapid
environmental change in the north.
Scientists like myself need to work together with
wildlife managers and harvesters to unravel the
complexity of responses to environmental change.
This information will be key to making decisions
about caribou going forward.
This article was originally published on The
Conversation. Read the original article.
Provided by The Conversation
APA citation: How will climate change affect Arctic caribou and reindeer? (2017, December 1) retrieved
24 March 2021 from https://phys.org/news/2017-12-climate-affect-arctic-caribou-reindeer.html
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