Christmas reindeer mystery as world's largest herd plummets
Mining, hydro & roads
However, in recent decades large parts of the herd's range have been disrupted by a series of huge projects. Iron-ore mining, flooding vast areas for hydro-power and road-building have all taken their toll, according to Innu people.
‘But all the massive industrial "development" projects that have been imposed on our land in the last forty years have undoubtedly had a cumulative impact on the size of the caribou herd. That is why we need real control over our territories and resources, and why we must be involved as equals in decisions that affect our lands and the animals that live there.'
The James Bay project alone severed almost completely in sectors the traditional Caribou wildlife ecosystem corridors in the East with many in the herds drowning as they tried to cross rivers. In 1984, 10,000 died at once. It should be noted that there is always mortality by drowning in rivers and lakes annually in herds and they are darn good swimmers, too. In the East & West, Caribou herds have been stressed from much of their food (lichen's etc.) depletion by the deterioration of their FEN’s (Forest Ecosystem Network) by historic mismanagement of the forest resources sector. Another aspect may include hunting policy, whereby cows were taken; old genetics, thus leaving herds under young cows who don’t have the developmental patterns of where to go and when. Also, the effects of pollutants cannot be disavowed on their biological nature, their genetic nature as Arctic regions have especially high concentrations of pollutants.
Statistics as @ 2001 –
In the Province of Quebec, Canada, caribou live in large wild herds, including the Leaf herd with 628 000 individuals and the George River herd with 385 000 individuals. The caribou generally travel upwards of 2,000 kilometres (1,200 mi) annually and live in an area of about 1,000,000 square kilometres (390,000 sq mi). Some individuals have been observed traveling 6,000 kilometres (3,700 mi) in a single year.
The caribou population varies considerably, for unknown reasons, and their numbers have apparently peaked in the later decades of each of the 18th, 19th and 20th centuries. The most recent decline at the turn of the 20th century caused much hardship for the Inuit and Cree communities of Nunavik, who hunt them for subsistence. By 1950, as few as 5000 caribou remained in northern Quebec and Labrador.
The George River herd, south of Ungava Bay, whose numbers reached about 800 000 towards 1993, had about 384 000 individuals in 2001. The Leaf herd in the west, near the coast of Hudson Bay, has grown from 270 000 individuals in 1991 to 628 000 in 2001. Inuit, Cree and southern sport hunters kill about 30 000 caribou each year in northern Quebec.
As noted, caribou have had periodic pre industrial declines also (some from mass hunting) which is little understood, conversely, just as in the case of the Leaf herds growth in 2001. It is possible that given their huge territories (up to 6 thousand kilometers), some herds may just wander off into none human habitat areas and then partially return. The calves are highly susceptible to mortality for a number of reasons such as size, snow, ice, water and of course predictors. Aside from the traditional animal predators, the insect or parasitic type, coupled with environmental conditions like excessive rain, winds or lack there of may also play a role in mortality. Here are a few items from project caribou:
From Project Caribou: _http://www.taiga.net/projectcaribou/pdf/allaboutcaribou.PDF
The caribou herd
Caribou need to be able to do two things at once: they need to eat, and
they need to keep watch for predators. Like many other animals, caribou
fill this need by gathering in herds. When caribou are in a group, several
animals will be looking up and around while others are eating. They sniff
the air regularly and can recognize predators by scent. They can alert
other caribou to danger.
Barren-ground caribou form different kinds of herds at different times of
the year. Prior to calving, pregnant cows will band together in small
groups called “maternity bands.” After the young are born, the mothers
and calves may form “nursery bands.” Larger and larger groups of
caribou may move together through the summer as a strategy to reduce
harassment by insects. When cool August nights mean fewer insects,
these large groups break up and animals wander in smaller groups until
fall. By early September larger groups again start to form and continue
through fall migration. In winter, bull caribou may avoid groups of cow
caribou and their calves, because they know that predators like wolves are
drawn to the vulnerable young caribou. Also, they may be challenged for
feeding territories by cow caribou, which still have their antlers.
There are other advantages to travelling in herds. By travelling together to
calving grounds in large groups, pregnant cow caribou in the barrenground
herds reduce the risk of predators killing their calves by sharing
the risk with thousands of others. As well, the animals in the centre of the
herd are better protected from predators, who may attack unprotected
animals or stragglers. In the same way, forming a tightly knit herd may
help caribou protect themselves from aggravating clouds of insects.
Woodland caribou are much more solitary. Prior to calving, pregnant cows
may separate to give birth and raise their calves in secluded patches of
forest. Caribou are most scattered across the range in summer. They do,
however, band together in the fall when males are courting females,
especially just before winter. Cows, calves and teenage caribou of both
sexes travel in small bands throughout the winter, while mature bulls
separate until late winter when, for a very brief time, most members of the
herd gather together in search of the fresh green plants that appear where
the snow has melted.
Tiny attackers: insects and parasites
There are other, much smaller members of the caribou’s habitat that can
have a big effect on the caribou’s health. Blood-sucking insects like
mosquitoes, blackflies, biting midges and bulldog flies are “micropredators”
of caribou. They persistently attack caribou to get the blood
they need to hatch their eggs. In summer, these flies often torment
caribou, distracting the calves from nursing and the adults from feeding.
Caribou will rush wildly about, trying to avoid insect harassment,
sometimes injuring themselves in the process.
Tormenting insects keep caribou on the move searching for windy areas
like hilltops and mountain ridges, rock reefs, lakeshore and forest
openings, or snow patches that offer respite from the buzzing horde.
Gathering in large herds is another strategy caribou use to block insects.
Parasites are dependent on the host animals that they live with for all or
part of their life cycle. Among the parasites that affect caribou are a variety
of worms, insects and microscopic animals called protozoa. Parasites
alone are unlikely to kill a caribou, but they may cause the animal to be
weak, malnourished, or generally in poor condition. They may also distract
them to the point where predators are able to
catch them more easily.
This is also, especially after Fukushima Daiichia, a large cause for worry:
Pollution caused by people living far from the territory of the caribou may
still have an effect on the caribou and those that depend on them. One
example of this effect is that of the radioactive element cesium.
Caribou depend on lichens as a primary source of food in the winter
months. Lichens take nutrition from moisture. Lichens grow very slowly
and live a very long time; because of this nutrients are more concentrated
in lichens than in other plants. Unfortunately, heavy metals such as
cadmium and cesium accumulate and become concentrated in the same
way. Cesium is passed along to caribou that eat the lichens. Radioactive
elements like cesium may be cancer causing.
In northern Canada, tests have shown the levels of contamination to be
low enough that Health and Welfare Canada has not recommended
against the human consumption of caribou meat. However, contamination
levels were so high in northern Europe after the Chernobyl nuclear
disaster that reindeer meat had to be destroyed. Even in Canada, levels of
contamination increased by up to 25% in some caribou herds after the
Cesium does not persist in the body tissues of caribou. This means that
the level of it found in the meat will be higher in winter, when the animals
are on a lichen diet, than in summer, when caribou eat a wider variety of
plants. However, other forms of pollution, like heavy metal fallout, do
accumulate in body tissues such as the liver and kidneys. The caribou of
the far north are a powerful symbol of the potentially devastating effects of
human activity, even on the other side of the world. Perhaps this example
will encourage people to understand that every action has a
Oil and gas development on calving grounds
Concentrated human activity in caribou calving grounds—such as oil and
gas exploration or development—could interfere with instinctive maternal
behaviours or cause cows to abandon traditional calving areas for less
favourable ones where food may be scarce or calves more at risk of
predation. At birthing times, cows are wary and will flee if disturbed.
Calves that are not yet steady on their feet may have a difficult time
keeping up with their mothers.
There are several theories about why barren-ground caribou return to
traditional calving grounds year after year. One is that caribou are avoiding
insects and predators present in greater numbers at this time of the year
on the southern parts of their range. Another is that cow caribou need the
new, nitrogen-rich vegetation that occurs on the calving grounds. For
whatever reason, traditional northern calving grounds are critical habitat
for many barren-ground caribou herds.