This year’s summer drought and unprecedented heat wave are expected to impact the fall migration of the endangered monarch butterfly, as revealed by researchers at the University of Ottawa. The extreme weather conditions may hinder plant nectar production crucial for fueling the monarchs’ journey to Mexico.
Associate professor Heather Kharouba emphasized climate change as a significant factor affecting monarch populations, with adverse weather conditions notably impacting the butterflies, as indicated by data from Mexico. Monarchs are a prominent butterfly species found across Canada, excluding Newfoundland and Labrador, and have been classified as endangered by Climate Change and Environment Canada since December 2023 under the Species at Risk Act.
Collaborating with the university, the government agency is investigating the impact of rising temperatures on essential plant species. In a study at a farm in Kinburn, Ottawa, researchers have set up netted cages around various plants, with some enclosures simulating increased temperatures akin to climate change effects.
Jenna Boomhower, a master’s student leading the research project, highlighted the importance of monitoring changes in flower behavior due to temperature variations. During heat waves, temperatures within the mini-greenhouses exceeded 50°C, affecting nectar quality and potentially posing challenges for monarchs in extracting nectar with their proboscis.
The dry summer conditions have further complicated the study, with drought causing thicker nectar and plant desiccation. This has impacted the availability of food for monarchs, prompting researchers to observe how these conditions influence the butterflies’ behavior.
The research, scheduled for completion by September 15, involves weighing and measuring monarchs to assess nectar quality and energy reserves. The team has bred over 300 monarchs for analysis, with some being released for migration. The study aims to provide insights into how monarchs adapt to changing environmental conditions and the implications for their long-term survival.