Breeding butterflies in BC
Posted onAugust 10, 2021by|, ,
This small, vibrantly coloured butterfly once thrived in Garry Oak ecosystems and wet meadows from the Comox Valley on Vancouver Island to Oregon’s Willamette Valley. But as recently as 2005, scientists believed this butterfly had disappeared entirely from Canada. Since then, two isolated populations have been found — on Denman Island and near Oyster River on Vancouver Island. Conservation breeding of Taylor’s checkerspots began in 2013 in a converted aviary on Denman Island. Two years later, we began releasing caterpillars into restored habitats on the island. Today, breeding has been moved to facilities at the Greater Vancouver Zoo, where we can produce thousands of caterpillars each year.
Getting butterflies to breed is a bit of a nuanced activity, and we only have a short window of time each year to make it happen.
In the Taylor’s checkerspot conservation breeding program in BC, our results for the whole year depend on what happens during the three week period when our butterflies are “on the wing”. From the moment the first chrysalis breaks open, the pressure is on to ensure that the next generation is produced. It’s so important to get things right, to be as prepared as possible, and to learn quickly.
In 2021, our preparation and learning paid off. We achieved the most success we’ve had with our breeding program to date – we now have close to 5400 caterpillars in our care! Below are some photos from our breeding season earlier in the summer.
Thank you to our partners in this program, and to the supporters of WPC for enabling us to do this work. By trying out science-based techniques and collecting data on the outcomes, we continue to advance the field of conservation breeding for the benefit of species at risk.
Each day we spent time feeding our 114 breeding butterflies – this female is enjoying some honey-water on a Q-tip.
A Taylor’s checkerspot chrysalis turns translucent like this right before a butterfly ecloses (emerges). This year we tried introducing butterflies to one another soon after eclosion – a change from the timing we have used in the past.
In 2021, we paired our butterflies 1-to-1, with a male and a female in each mesh enclosure. We also recycled this rabbit hutch as a safe spot to store our butterflies outdoors. These two changes allowed the butterflies to experience temperature and moisture conditions closer to those that their wild counterparts would experience, as well as allowing males and females to have consistent access to each other for 24 hours a day.
These butterflies are displaying a classic breeding pose. The female is the top butterfly, while the male hangs upside-down from her abdomen. In 2020, 8 pairs bred through the whole season. In 2021, on one especially thrilling evening, we had 9 pairs hanging like this all at once! We learned that this early-evening time window might be a key to success – many pairs this year bred between 4-7pm.
After successfully breeding, females showed a visible sperm plug at the base of their abdomen (see the bright white dot). This sperm plug likely contains not only male DNA but also proteins that the female can use when she lays hundreds of eggs. This sperm plug is common in butterflies but varies in function and appearance between species. We also learned that it disappears quite quickly – one of our 2021 females bred in the morning and laid eggs that same afternoon.
This female was one of about 25 who laid productive eggs. Our bred females produced an average of about 200 caterpillars each, with one female producing over 400 on her own. We are so excited about what we have learned this season, and how that will allow us to do even more to save this species from extinction.
Michelle is a Conservation Biologist and Field Naturalist with a special interest in Lepidoptera (butterflies and moths) and Herpetiles (reptiles and amphibians). Currently, she is the technician of WPC’s Taylor’s Checkerspot Butterfly program in Abbotsford, BC. She has worked with conservation projects for species at risk such as monarch butterflies and the turtles of Ontario.