magazine / jun10
Overheated hot spots
The pygmy hog lives in a great neighbourhood. So why is it nearing extinction?
By Steven Fick and Chloé Melançon Beauséjour
|
| Click map to enlarge |
Biodiversity on a planetary scale plays out in a predictable
manner. The diversity of species generally increases nearer
the equator, likely due to greater exposure to solar energy.
While there are exceptions, this pattern clearly appears on a global
map of mammal species, shown at top right.
Unfortunately, those same biodiversity hot spots are heating up
for more ominous reasons. As can be seen on the map at bottom
right, some of the richest natural regions on Earth are also among
the most threatened.
The evidence comes from the International Union for
Conservation of Nature (IUCN), the world’s largest global
environmental network. IUCN produces a scientifically based
inventory of biological diversity, called the Red List of
Threatened Species, that evaluates the risk of extinction for
thousands of species.
The prospects for mammals are not promising. Of all known
mammals, 21 percent appear on the Red List as vulnerable, endangered
or critically endangered.
One of those, at 25 centimetres tall, is the aptly named pygmy
hog, the world’s smallest wild pig. Endemic to the Himalayan
foothills, the pygmy hog is found nowhere else in the wild. You
would think it would benefit from its prime location: like many
regions in the tropics, the Himalayas support a rich diversity
of species.
Not so. Despite reintroduction efforts and conservation programs,
the pygmy hog is on the brink of extinction. With fewer
than 250 mature individuals confined to India’s Manas National
Park, the species is on the Red List as “critically endangered.”
Far from tropical hot spots such as the Himalayas, Canada has
relatively lower biodiversity and fewer species under threat. But
that means losing a species would leave a gaping ecological hole.
Says McGill University’s Andrew Gonzalez, a Canada Research
Chair in Biodiversity, “If you have two species and take one away,
you can have a huge impact on the ecosystem.”
top
|