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Wild Animal Traps Do Not Discriminate. Our Database Lists the Cats, Dogs, Others Who Suffer

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Bears in Canada — A Primer

Published 01/25/11
By Barry Kent MacKay, senior program associate

There are eight species of bears in the world and at least 44 “extant taxa,” meaning distinct subspecies, or “races.”

A subspecies is a group of animals who are, within the species they belong to, distinctly similar to each other but different, usually in very subtle ways, from other members of the species. Where their populations overlap with another subspecies, they freely interbreed.

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Cormorants: Wildlife Management North and South of the Border

Published 01/25/11
By Barry Kent MacKay, Senior Program Associate

(Photo by Jeff Jones)

Wildlife managers in Canada and the United States both seek to find reasons to kill cormorants in response to pressure from the concerns of sport and commercial fishers who believe that cormorants eat too many fish. In the United States particularly but also in Canada there are the additional concerns of aquaculturists (fish farmers), primarily in the southern States, about cormorants and other piscivorous birds eating their stocks.

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Cormorants: Energy Transference, Basic Physics and the Technology Prosthesis

Published 01/25/11
By Barry Kent MacKay, Senior Program Associate

Double-breasted cormorant
(Painting by Barry Kent MacKay)

To understand why cormorants cannot eliminate fish, one must have at least a very elementary understanding of how all creatures exist. Put simply, we all need to have food that can be converted by our bodies into tissue, energy and warmth. This conversion process is called metabolism, and is a two-part process. Food provides us with the means to create cells and tissues and organs and fats. But the energy we expand in order to acquire food consumes our physical being.

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Cormorants: Back in the Real World

Published 01/25/11
By Barry Kent MacKay, Senior Program Associate

But such absurd scenarios (see Cormorants: Energy Transference, Basic Physics and the Technology Prosthesis) don’t happen in the wild, which is why both fish and cormorants continue to co-exist as they have for millions of years. To be sure, in North America one species of cormorant and several species of fish have been exterminated, but that is because humans, utilizing not their own metabolic energy but the energy derived from their technology, destroyed them.

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Cormorants: Food Chains and Basic Ecological Principles

Published 01/25/11
By Barry Kent MacKay, Senior Program Associate

Double-breasted cormorant
(Painting by Barry Kent MacKay)

A cormorant lays only a few eggs. Depending on the species and the age of the individual, fish lay a great many eggs — dozens , hundreds, even many thousands. As a general guideline all those newly hatched fish are in competition with each other for resources (food) and in turn are close to the bottom of the food chain, consumed by various predators, in some cases including older, thus larger, individuals of their own species. Most of the fish of interest to anglers and commercial fishers are likely to die before they are big enough to be of interest to cormorants, but there are, at the outset, a great many of them.

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Cormorants: The Alewife, Alien Salmon and Trout, and the Double-Crested Cormorant

Published 01/25/11
By Barry Kent MacKay, Senior Program Associate

(Photo by Maha Rashi)

Two fish important to the double-crested cormorants in the Great Lakes are the alewife and the round goby.

Alewives are a shad-like fish that is native to the east coast, where it lives in seawater but moves into rivers to spawn in fresh water. No one can say with absolute certainty when or how the alewife reached the Great Lakes, but it was first recorded in Lake Ontario in 1837.

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Cormorants: The Round Goby

Published 01/25/11
By Barry Kent MacKay, Senior Program Associate

(Photo by Jeff Jones)

But if the cormorant’s taste for alewives is seen by wildlife managers as a negative, placing them in competition with alien salmon, there is another alien species to be considered: the round goby.

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Cormorants: The Difference Between Science and Management

Published 01/25/11
By Barry Kent MacKay, Senior Program Associate

Double-breasted cormorants
(Painting by Barry Kent MacKay)

Such terms as “science” and “scientist” are often broadly used to include practices that are not science and individuals who may or may not be scientists and may or may not practice science. For the purposes of better understanding cormorants or any other wildlife species it is important to distinguish between “science” and “management.”

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