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
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