It has been a busy last 10 days as the weather has final warmed up again in the Fraser Valley. The Taylor’s Checkerspot Butterfly captive breeding program at the Greater Vancouver Zoo in Aldergrove has successfully reached and exceeded our goal for this years egg numbers with an unofficial 1100 eggs to date, with more to come in the coming days.
Due to the spout of cold weather during the middle to end of May many of the butterflies were bred unsuccessfully a number of times but majority of the females bred successfully with a second or third attempt. Fortunately, the cold weather has enabled the butterflies to extend their lifespan, some of which have lived over a month now with the first to enclose on April 28.
When the females have been bred they are separated into their own small enclosures with some bloomed flowers, honey-water, and a ribwort plant for laying. They are checked and fed twice daily and any laid eggs are noted. Butterflies are “cold-blooded” so warm weather and sun helps to initiate egg laying. Since butterflies do not generate enough heat from their own metabolism they need the energy from the sun to increase their internal body temperature. This is why the bred females are placed outside daily in their enclosures to catch some rays!
Once the females have laid a decent number of eggs, anywhere between 20-100, they are moved into a larger enclosure with other females that have already laid. The ribwort plant is removed and placed into a plastic container, watered and checked daily to see the progress of the eggs. The eggs are yellow in color when laid and will slowly become red, darkening to a dark silver colour before hatching.
The first eggs to be laid have successfully hatched and we now have a group of tiny TCB caterpillars in their first stages of life! These small caterpillars are moved from the larger container, containing the ribwort, and into a smaller plastic cup with the leaf they hatched on. Once they begin to move about and start eating they will be given more ribwort leaves to feed on.
As the eggs have been laid over the course of 3 weeks, they are all at different stages but we expect to see many more new baby caterpillars hatching over the rest of the week.