B.C.'s Diversity Needs Protecting

June 24th 2007

Peace Arch News, Page 0022, 24-Jun-2007
By Roy Strang

Prevention is more effective than a cure

British Columbia is by far the most diverse province in the country in many aspects ˆ animals, climate, plants and terrain.

It is home to 76 per cent of the country's birds, 72 per cent of the freshwater fish and 60 per cent of coniferous species.

It is probably in B.C. that one has the best hope of seeing grizzly bears, cougars, and wolves. Kermode bears are unique to the province and most, if not all, of the country's mountain caribou and mountain goats are here also.

Although we enjoy this richness, the province is not doing enough to protect it.

About a third of the species present are at risk yet few are protected by provincial legislation. The government's own data shows that two-thirds of reptiles and turtles are in danger of local extirpation, as are about one fifth of our birds.

Already, in 150 years, we've lost 49 species, such as the great sage grouse and the western pond turtle.

Despite these documented losses, fewer than 68 species are protected by B.C. law, and there is no legislation to protect endangered species.

While we have lost, or risk losing, many species of birds and animals, we are gaining others. Unfortunately, many must be classed as undesirable aliens.

In 1970, a few eastern grey squirrels were introduced into Stanley Park. Now they have spread as far east as Langley and, along with their melanistic, black cousins, are driving out the smaller, native Douglas squirrel, just as in Britain the greys are ousting the native red squirrel.

Recently, two damaging cutworms have arrived from Eurasia and threaten to spread also.

Cats were brought to North America little more than 100 years ago. Though they undoubtedly give much pleasure to their owners, they are a significant factor in the decline in numbers of small birds.

Unlike natural predators, their numbers do not fall in step with their prey.

Data from Wisconsin indicates that the annual kill by domestic and feral cats could exceed 200 million birds.

There's a similar story in our plant world.

About 100 years ago, knapweeds were brought in hay imported from eastern Europe. Now they are a major pest in the interior rangelands where they supplant the nutritious native bunchgrasses to the detriment of carrying capacity. Although much research effort has been applied, the knapweeds are defying control measures and are spreading.

Purple loosestrife is another damaging Eurasian import.

In tidal waters, Spartina grass is replacing native eelgrass to the detriment of habitat for infant fish.

Similar problems are found in parks and natural areas. English ivy, Himalayan blackberry and dead nettle are all aggressive and can easily take over from native vegetation. All are spread as seeds in bird droppings, by suckering or by thoughtless discarding of garden wastes.

Invading animals and plants are often successful in their new environment because they have no natural enemies in the new habitat. They are thus able to multiply and spread rapidly.

What's to be done?

Habitat protection is the best safeguard for endangered animals, but we have no control over the alternative habitats of migratory species, so international co-operation is necessary as well as local protection.

Legal hunting must be limited and co-ordinated with population numbers and fecundity while poachers should not be tolerated at all. Appropriate legislation to protect all endangered species is desirable.

It's important to be leery of bringing new plants into any area. Phytosanitary regulations are in place for good reason and should be scrupulously observed and enforced. Accidental import calls for care; after visiting outside the country, be sure to remove all traces of soil and plant fragments from clothing, footwear and equipment before returning home.

Garden supply outlets should be discouraged from marketing known problem plants like ivy.

This is a case where prevention is much more effective than cure.

Dr. Roy Strang writes weekly on the environment for the Peace Arch News. westerlea@shaw.ca

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