Conserving Biodiversity - Species at Risk



Conserving Biodiversity - Species at Risk

Please read the information below, and then answer the questions at the bottom of this page on a separate piece of paper.

If limiting factors increase in an ecosystem, then the populations of some species may decline. In many cases, the decline in biodiversity is due to human impact. Conservation biologists are scientists who assess which species are most in danger of extinction. They develop strategies to protect them.

An extinct species is a species that no longer exists.

Example: The passenger pigeon used to be one of the most common North American birds in the 1800s. One flock in 1866 was described as being 1 mile wide and 300 miles long, and held more than 3.5 billion birds! The pigeon’s population decline was due to both hunting and habitat destruction. Eureopean settlement in North America led to mass deforestation, and pigeons were hunted as cheap meat.

At risk species are native species that are in danger of becoming extinct or disappearing from a region. There are different levels of risk, as described in the table below.

|Level of Risk |Definition |Canadian example and reasons the species is at risk |

|Extirpated |A species that no longer exists in |Black-footed ferret |

| |Canada, but still occurs elsewhere.|loss of habitat (prairies) |

| | |limited area where their prey are located (they feed mainly on prairie dogs) |

|Endangered |A species that faces imminent |Blue whales |

| |extinction or extirpation. |whaling |

| | |collision with ships |

| | |pollution |

| | |tangled in fishing gear |

|Threatened |A species that is at risk of |American white pelican |

| |becoming endangered if limiting |disease (avian botulism and West Nile) |

| |factors are not reversed. |pollution |

| | | |

|Special Concern |A species with characteristics that|Climbing prairie rose |

| |make it sensitive to human |land development & agriculture cause loss of habitat (it grows well in clearings with no shade).|

| |activities or natural events. |ATVs damage the roses |

| | |invasive shrubs out-compete roses |

Conservation Strategies

In Canada, the status of species is monitored by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). When a species is placed in the endangered or threatened category, another agency, RENEW (REcovery of Nationally Endangered Wildlife), prepares an action plan to ensure the recovery of the species. Conservations strategies might include:

o Protecting species in their native habitats (creating protected areas, restoring habitats, protecting species from predators, reducing habitat loss, etc).

o Protecting species in human-made environments (like zoos), and then re-introducing the species back into their native habitat.

The Endangered Species Act

• An Ontario law that prohibits killing, capturing, selling, or trading species that are endangered in Ontario.

• This law also protects their habitats – it is illegal to damage or destroy ecosystems that the species depend upon.

Questions:

1. Extinction is a naturally occurring practice; over millions of years, some species become extinct while new species arise. Unfortunately, human activity has drastically increased the rate of extinction. Brainstorm some of the main human activities that contribute to species extinction.

2. a) Why was the extinction of the passenger pigeon so surprising?

b) What caused its extinction?

3. List and define the four at-risk classifications, and give an example of one species in each class.

4. Describe the role of COSEWIC and RENEW in protecting our country’s biodiversity.

5. Describe how the Endangered Species Act helps to protect at-risk species.

6. Create a list of actions an individual could take to help protect at-risk species.

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