Reptiles first appeared on Earth around 260 million years ago and the number of species
quickly expanded as species occupied a variety of ecological niches. Today, we are losing
populations and entire species of reptiles because of increasing changes we are making to
the world. Many reptiles are long-lived and do not produce many young so they are sensitive
to rapid changes to the environment. To date, Canada has lost two species of reptiles: the
Lizard in British Columbia and the
Timber Rattlesnake from
southern Ontario. There are a number of threats to reptiles and we list some of the major
ones faced in Canada:
The destruction of forests and wetlands affect many species of wildlife. The Pygmy
Short-horned Lizard may have been eliminated from British Columbia because of the increase
in agriculture in that area. Likewise, the
Blue Racer, now found only on
Pelee Island in southern Ontario, is facing extinction in Canada from development on the
Thousands of reptiles are killed every year on our roads and highways. Many snakes are
drawn to roads in the evenings because the tarmac is warmer than the surrounding
environment. When large hibernacula are separated from the summer range by a road,
slaughter is often the result. In Manitoba, up to 10,000
are killed annually, primarily during the fall, along a 3 km stretch of road.
Turtles also often fall victim to cars, particularly in early summer when adult females
are looking for good nesting areas to lay their eggs. Because most turtles are long-lived,
with low rates of adult mortality, even slight increases in mortality can wipe out an
||Click here to learn how you can help reduce turtle road
There is a fine balance between predators and their prey. When a predator specializes on
another species the two populations tend to keep each other in check. However, many
predators prey on many different species and eliminating one prey species does not affect
their populations. Many snakes and turtles are particularly prone to nest predators such as
Raccoons and Skunks. Such species have flourished around areas of human settlements and it
is estimated that there may be twenty times as many Raccoons in North America now, compared
with half a century ago. In many areas, Raccoons destroy virtually all nests made by
Pollution is an increasing problem as new chemicals continue to be created and sold. Many
toxins such as polychlorinated biphenyls (PCBs), dioxins and furans are absorbed by animals
in the food they eat. Animals higher up the food chain often have very high levels of
contaminants because each prey species down the food chain has concentrated the toxins.
Females often secrete these contaminants into their eggs. In the Great Lakes basin up to
40% of Eastern Snapping
Turtle eggs in some areas either do not hatch or result in deformed young. In addition,
DDT and its breakdown products are still found in the tissues of
Eastern Snapping Turtles
despite its ban in Canada in 1972.
Other chemicals may not cause death or obvious deformities but have just as important
effects. Certain chemicals are very similar to natural hormones and can affect individuals
reaching maturity. For example, some chemicals will mimic the female hormone estrogen and
can prevent juvenile males from properly maturing. It is unclear what effects these
chemicals are having on humans.
The reptile pet trade is big business. Most companies are conscientious, honest and
reputable. They raise animals in captivity and ensure that would-be owners know what they
are getting into when they purchase an animal that may live 20 or 30 years. Unfortunately,
others simply see a way to make a quick buck or two. The collecting of wild animals to be
sold as pets is a notorious practice which can have devastating effects on a population.
One unscrupulous dealer even approached a Canadian university professor, who has
dedicated his life to reptile conservation, with the offer of buying all the
Wood Turtles he could
catch. He also had advice on how to catch the entire population.
If you wish a reptile as pet make sure you are dealing with dealer that can be trusted.
Find out where the animals come from. Talk with other pet shops or even local conservation
officers to find out if any complaints have been lodged against the dealer. Don't let your
interest in a species help cause it to go extinct.
Unwanted pets are often released into the wild. Most perish in a short time, either because
they are tame and therefore not wary of predators, or they cannot cope with the long, cold
Canadian winter. Some individuals do survive and appear to even thrive in their new
homeland. That is a problem, because exotic species can cause a number of problems. First
of all, exotic species compete with native species and may actually be able to displace
some native species. Exotics may also bring foreign diseases that native species are not
able to cope with.
The most widespread exotic species in Canada is the Red-eared Slider, a turtle native to
the southeastern USA. Although their importation to Canada is now banned, eggs are still
imported. From 1992-1996, US government records indicate almost 500 000 eggs entered
Canada. These turtles are sold as 3-4 cm juveniles, but when they reach 10-15 cm in length
many people release them. Red-eared Sliders are quite common now in the Great Lakes area.
Over 100 are known to live at Riverdale Farm in Toronto, where they have virtually
displaced all other species of turtles. Other introduced species in Canada include the
Eastern Box Turtle in southern Ontario and the Western Pond Turtle (now extirpated) and
the Common Wall Lizard in British Columbia.
Eliminating exotic species is difficult and what should be done with the individuals? It
is generally impossible to return them to their native area and often euthanasia is the
only solution. It is unfortunate that the animal must pay for the mistakes of humans.
Many people do not like reptiles, particularly snakes. The Timber Rattlesnake was wiped out
from Canada because of deliberate persecution. While a healthy respect for rattlesnakes is
necessary as a bite can be fatal (though generally it is not), these creatures are not
unusually aggressive. A rattlesnake's rattle is to alert you to keep your distance. If it
wanted to attack, it would not signal it's intent first. The rattlesnake's venom is for
immobilizing its prey, which is generally small mammals. Rattlesnakes don't eat people and
they only attack people when threatened. More people die from bee stings every year than
from snake bites.
Despite this many people kill rattlesnakes on sight. Unfortunately a number of other
snakes will imitate a rattlesnake by vibrating their tails in dry leaves. Such action may
deter some would-be predators, but it causes many harmless snakes to be killed.
In a world where one group of people cannot get along with another group because of
cultural, religious or political differences, it is probably too much to expect that one
species that considers itself intelligent can show tolerance for other species. But we
can always hope.
If you would like to read more about reptile conservation or particular species you might
like to check out the following articles: