SPECIES AT RISK – PAGE 11

In Canada, species are given one of five levels based on how much at risk they are.

• Extinct [12 in Canada]

Any species that no longer exists anywhere on earth.

Great auk

hunted

Banff long-nosed dace

accidental

Labrador duck

hunted

2. Extirpated [21 in Canada]

Any species that no longer exists anywhere in Canada.

Timber rattlesnake

persecuted

Frosted elfin

accidental

Black-footed ferret

eliminated food

3. Endangered [141 in Canada]

Any species close to extinction in all, or part, of Canada.

Swift fox

persecutedNorthern cricket frog

accidental

Eskimo curlew

hunted

4. Threatened [99 in Canada]

Any species likely to become endangered, if things don’t change.

Wood bison

disease

Least bittern

accidental

Killer whale

pollution

5.Vulnerable (Special Concern)

[142 in Canada]

Any species that is at risk due to low or declining numbers.

Grizzly bear

persecuted

Spotted turtle

pet trade

Peregrine falcon

pollution

FACTORS INFLUENCING STATUS

a.Size

Both eat a similar diet, BUT one eats much more & so needs to move more to find more food

Larger animals need: more food; more space.

A carnivore is at greater risk because its food may become rare more readily than a herbivore’s food will become rare.

The frog is at more risk than the shrew as it eats only crickets

b. Diet

Also, a specific diet is riskier than a general diet.

c. Biotic Potential

Mice breed much faster than buffalo.

Birth rate, survival to reproductive age, births per year and births per lifetime are all part of this.

d. Range of SpeciesAn animal that has a small species range is at greater risk as something may happen to that range..

The species at left has a smaller range and so is at a greater risk.

e. Range - Individual

A larger individual range puts the species at greater risk as they roam to find food, mate, etc.

f. Human Interactions

Killed from fear;

Some animals do well around people and some do not.

by cars.

Some avoid humans;

Some are poisoned.

FOLLOW-UP ASSIGNMENT

Now lets try to put some of this knowledge into practice.

turn to chart on next page

A B C D E F

diet

size

biotic potential

range -species

human interactions

small small smalllarge large large

herbivore herbivorecarnivore carnivore omnivore omnivore

high high lowlow high low

large large largesmall small small

many few fewmany many few

range-individual

small large smalllarge small large

negative traits; A –1; B – 4; C – 4; D – 1 ½ ; E – 5; F – 2 ½