This year’s summer drought and unprecedented heat spell may impact the upcoming fall migration of the endangered monarch butterfly, as per findings by University of Ottawa researchers. The extreme weather conditions could hinder the production of nectar crucial for the monarchs’ journey to Mexico.
Associate professor Heather Kharouba emphasized climate change as a significant factor, noting its increasing threat to monarch populations since 2005. Adverse weather conditions have been shown to have a detrimental impact on monarchs, especially evidenced from data collected in Mexico.
The monarch butterfly is a widely distributed species across Canada, except for Newfoundland and Labrador, as outlined by the government. Classified as endangered by Climate Change and Environment Canada since December 2023 under the Species at Risk Act, efforts have been made to understand how rising temperatures affect the plants vital for monarch survival.
Collaborating with the university, Kharouba’s team conducted research at a farm in Kinburn, Ottawa, implementing netted cages around various plant species to investigate the effects of simulated climate change. The study, led by master’s student Jenna Boomhower, aims to monitor changes in flower patterns and their implications on the monarch population.
Amid this year’s heatwaves, temperatures inside the mini-greenhouses spiked, impacting nectar quality and availability for the monarchs. Researchers observed challenges faced by the butterflies due to the thickened nectar caused by the drought, likening the struggle to extracting nectar with a small straw from a milkshake.
The ongoing experiment assesses the monarchs’ response to the altered conditions, including the impact of the drought on plant survival and nectar quality. The team plans to analyze their findings comprehensively post-September 15, having bred over 300 monarchs for further evaluation and migration release.
