The Greater Vancouver Zoo is wrapping up yet another season of conservation efforts.
The results are in for their head starting and captive breeding programs for three species of locally endangered animals: Western Painted Turtle, Oregon Spotted Frog, and Taylor’s Checkerspot Butterfly.
“This is a very exciting time of year as we get to see the end of season results of our work over the busy spring and summer period,” said zoo animal care manager Menita Prasad, BSc.
It was a successful season for the Western Painted Turtle. Of the 291 eggs salvaged from wild nests, eggs produced by captive breeding, and one clutch extracted from a female that was run over by a car, 183 were successfully hatched in July and August.
These turtle hatchlings are kept awake over the winter season and offered plenty of food to encourage growth and to give them a head start so they are ready for release back into the wild in 2017.
In the meantime, as the temperature drops below 10 degrees Celsius, the adult Western Painted Turtles – the ambassadors for the captive breeding program – are slowing down in preparation for winter brumation (prolonged dormancy during cold weather), and will sleep soundly until they awake next spring.
It was a slow season for the Oregon Spotted Frog. Very cool temperatures through much of June and July resulted in delays in tadpole and frog growth and metamorphosis. Some tadpoles were able to metamorphosize during small warm breaks in the weather, however, most did not transform until August, if at all.
During the first week of September when frogs are measured and marked prior to release, only 20 per cent of the frogs had reached releasable size. The remaining tadpoles/frogs will be housed indoors and fed during the winter season, allowing them to grow and hopefully metamorphose before spring, at which point they will be marked and released.
It was a successful first year for the Taylor’s Checkerspot Butterfly. This marks the end of the first year of the zoo’s involvement with this program.
The Greater Vancouver Zoo received 100 caterpillars from the Denman Island facility at the end of March. From these caterpillars 85 transformed into butterflies. The butterflies went on to produce 1,100 eggs, of which 500 hatched into caterpillars.
In mid-August as the temperature began to drop, 480 individuals have entered into diapause (a period of suspended development). These caterpillars will stay in this state, not eating or moving and webbed up safely until they awake in the spring, ready to eat, grow, pupate and breed.
Some of the caterpillars will be retained for the continuation of the breeding program in 2017, and the remainder will be released to the restored, historical habitat on Denman Island to grow and support these last remaining populations in Canada.
All of these efforts at the zoo would not be possible without the collaboration of the Oregon Spotted Frog Recovery Team, the Western Painted Turtle Recovery Team, the Garry Oak Ecosystems Recovery Team, the BC Ministry of Environment, and Wildlife Preservation Canada.
Established in 1970, the Greater Vancouver Zoo is dedicated to conservation, preservation and the protection of endangered species. The Greater Vancouver Zoo is an accredited institution within Canada’s Accredited Zoos and Aquariums (CAZA), a non-profit organization established to promote the welfare of animals and encourage the advancement of education, conservation and science.
Learn more at the website: www.gvzoo.com