Climate change spells bad news for reindeer, say experts
- 17 Jul 2014, 11:40
- Roz Pidcock
If you look at one corner of the Arctic, you might
conclude climate change means reindeer are better off. But those
that benefit are likely to be the exception rather than the rule,
Overall, warming is leading to loss of habitat, food
and declining reindeer populations.
According to an article in yesterday's
Times, reindeer numbers are growing on the Norwegian islands of
The piece is based on data from scientists at the
Arctic University of Norway, who have monitored reindeer
populations in Adventdalen Valley on Spitsbergen, Svalbard's main
island, since 1979.
The new research suggests the reindeer of Svalbard may
be doing OK out of climate change, as melting ice reveals new
grazing territory. But this is the latest estimate from one group
of researchers, and not all scientists are as confident of such a
Getting a handle on reindeer numbers in these vast and
remote landscapes is difficult. This Smithsonian
feature from March explores researcher Steve Albon's
efforts to monitor reindeers in Svalbard, where he says the impact
of climate change is not yet well understood.
Reindeer in decline
Svalbard is just one part of the Arctic where reindeer
live. And the picture looks very different in some other parts.
Across the Arctic as a whole, reindeer are in decline.
Populations peaked in the 1990s and 2000s. Since then, studies show
wild reindeer and caribou populations have fallen globally by about
a third, from
5.6 to 3.8 million. In parts of North America, wild reindeer
populations have dropped
by more than 75 percent.
How reindeer populations are faring across the Arctic. Green
is increasing, red is decreasing and orange is unknown. Source:
Arctic Biodiversity Trends 2010
One of the two big reindeer populations in west
Greenland declined from about 45,000 to 35,000 between 2001 and
2005. Scientists don't have enough data on the second one to know
for sure how numbers have changed.
Though most of the larger Arctic herds are
declining, studies show some smaller populations in Fennoscandia,
Russia and Alaska have
remained stable or increased in the last few
So what makes some reindeer populations winners
and others losers?
Winners and losers
Part of the reason for declining reindeer
numbers is likely to be natural factors, driven by continental and
atmospheric changes, scientists say. But greenhouse gas warming
makes for a far more complicated picture, and is preventing
reindeer populations from recovering.
Reindeer experts Liv Solveig Vors and Mark
Stephen Voyce from the University of Alberta looked at the role of
climate warming and landscape change in the global decline of
reindeer in a 2009
"While caribou and
reindeer populations historically fluctuated, the current
synchronous population declines emphasize the species'
vulnerability to global change."
Since reindeer and caribou populations peaked in
the 1990s and 2000s, numbers have fallen globally by about a
Arctic Biodiversity Trends 2010
The impact of climate change on food
availability is an important reason for changing populations. As
warming melts ice and extends growing seasons, there's more
opportunity for the plants and shrubs reindeer feed on to grow. But
in other places lichen, one of reindeer's most important winter
foods, is decreasing and putting populations under
Research suggests warmer winters mean more
precipitation falls as rain rather than snow, which refreezes and
blocks reindeer's access to vegetation. Albon's team
reported the average weight of adult females
was about nine kilograms lower after a wet winter than one with
average rainfall. More frequent wet winters could damage the health
of the population, the scientists warn.
However, hard evidence about the impact of warm
winters on feeding habits is still fairly thin
on the ground, and not
all scientists agree it's a problem.
studies suggest plant growth could become out of sync
with when reindeer calves are born, meaning fewer survive. And
where reindeer do have access to food, its nutritional quality may
be declining. The latest report from the Intergovernmental Panel on
Climate Change (IPCC)
"[T]he overall quality
of forage may decline during warming, for example if the nitrogen
content of key fodder species for ungulates were to drop during
There aren't any simple answers for how climate
change is affecting reindeer. It varies depending on where in the
Arctic you look, which is why it's important to take a broad
Human activity also affects reindeer numbers
beyond just changing the climate. Scientists say in Russia,
hydrocarbon extraction is a bigger threat than climate change to
But the bottom line from scientists is that while some
small populations may be bucking the trend, further warming spell
bad news for reindeer right across the icy expanses of the