Friday August 13, 2010
Western Toads No Longer On Roads
Ryder Lake back to normal after migration
teve Clegg of Fraser Valley Conservancy confirmed in an e-mail to the Voice that the Western Toad Migration is over for this year.
"The Western Toad program is now over and all roads are open. We anticipate using the data collected this year to help implement long term solutions in the years to come. An official 2010 program summary document is in draft form and is soon to be released," said Clegg.
Western toads underwater at Hornby Lake, Chilliwack.
Ryder Lake Amphibian Monitoring and Rescue
Where:Nestled in the southern mountains of Chilliwack, British Columbia, Ryder Lake is a relatively large (approx 11,000 acre) rural agricultural community well connected to wilderness that results in rich wildlife diversity. The Ryder Lake Amphibian populations breed in many privately owned wetlands and ponds in the area.
Life History: Over the course of their life, Western Toads use a variety of habitats other than wetlands including forested summer range and winter hibernation sites. Western Toads can live as long as ten years, with the potential to breed six or seven times during their life.
Whatís happening in Ryder Lake: Amphibians, including the Western Toad make a series of migrations each year, once to reach breeding grounds, once again to return to their forest home, and finally their offspring cross in the summer to reach more favorable forest habitats. During each migration many amphibians successfully cross the roadways, while many others are killed by vehicle traffic.
Threats: Some threats to amphibian populations can include habitat fragmentation, roadways intersecting migratory routes, human induced changes to wetland breeding sites, and the alteration of their forested range. Climate change also presents a risk to amphibian populations through changed weather patterns that can cause unpredictable migration timing and patterns.
Importance to Biodiversity: Amphibians play a vital role in any ecosystem. Healthy amphibian populations consume enormous amounts of plant material and insects during their lives: things that many other animals do not eat; and in turn, amphibians are eaten by a number of different predators. Over 98% of a yearís population is eaten by others creatures. Birds such as the Stellarís Jay, snakes and small mammals are frequent eaters of juvenile toads. Adult amphibians provide a food source for larger raptors and predators such as coyote and raccoon.
Why: Vehicular mortality of amphibians during the three yearly migrations is cause for concern and is an un-natural event. As many amphibians are already destined for the bellies of predators, extra vehicular deaths further reduce survival rates of the population. Due to the continuing fragmentation of habitat in the area, and their importance to the community; the efforts to protect the population and ecosystem in the area is necessitated. The monitoring and rescue program initiated by the Fraser Valley Conservancy (FVC) brings awareness to this issue and provides support for more permanent long-term solutions and protection.
Who: The FVC is a local non-profit charitable society dedicated to protecting the ecological richness of our Valley. The FVC is funded for this program by the Government of Canada Habitat Stewardship Program for Species at Risk, Fraser Salmon and Watershed Program, TD Friends of the Environment, and the Kids for Ryder Lake while supporters and other contributors include Gidney Signs, Ryder Lake Farmerís Institute, Ryder Lake News & Views, and the City of Chilliwack.
What: The FVC is coordinating an adult monitoring (Feb-May) and juvenile rescue each summer while planning for more long term solutions with the community and local government.
Which amphibians are affected: Western Toads and Red-legged Frogs are species of conservation concern in Canada. They are listed by COSEWIC (Committee on the Status of Endangered Wildlife in Canada) as Special Concern and protected under the Federal Species at Risk Act. Pacific Tree Frogs, Northwestern Salamanders, and Rough Skinned Newts also breed and migrate in the area.
Western Toad Biological characteristics: Site fidelity Ė just how salmon return to their home stream to spawn, most adult Western Toads return to their natal wetland each year to breed. Female Western Toads can lay up to 16,000 eggs in one season.
Amphibian Development: Eggs hatch into tadpoles in 3 to 12 days depending on water temperature then tadpoles can take up to eight weeks to become land dwelling toadlets.
More about Western Toads: Adult toads spend the majority of life in moist forest habitats. Breeding adult toads migrate to their wetland each year in the spring (February-April) to breed. Once they are finished breeding they return to their forest habitat (April-May). At the wetland, the eggs first develop into tadpoles, then the young amphibians (called toadlets and froglets) migrate to the forest habitats around and beyond their birth place. Adult Western Toads can migrate as far as 2 km from their breeding grounds. Western Toads may spend up to three years maturing into adults.
For more information or to help visit their website www.fraservalleyconservancy.ca
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