The monarch butterfly is one of the most well-known butterfly species in the world, making it an international symbol of nature conservation. This is especially as the monarch serves as a vital sentinel on our continent. The presence or absence of monarchs tells a lot about the changing environmental conditions in North America.
A concerning message
Each year, various conservation organizations assess and publish the size of the populations that have reached their overwintering sites, either in Mexico or California. In Quebec, during the summer, we welcome the Western colonies that overwinter in Mexico. Thus, in December 2024, the area occupied by the monarch in Mexico has doubled, to 1.79 hectares of forest, while we found it on only 0.9 hectares in 2023. Although the population has increased and we are pleased about this, the trend remains downward and is undoubtedly alarming. (For information, experts estimate that one hectare would be occupied by approximately 50 million butterflies.)
Over a 20-year period, monarch populations have declined by more than 85%. The Government of Canada listed the majestic butterfly as endangered under the Species at Risk Act (SARA) in December 2023.
Against all odds
Several factors influence the size of the population counted each year. Intensive agricultural activities, as well as urban and industrial sprawl, reduce the number of suitable breeding sites and available food resources. Also, the weather conditions encountered during spring and autumn migrations, long journeys of approximately 4,500 km, have a significant impact on travelers weighing less than 0.5 grams. For example, climate change increases the likelihood of droughts, violent storms, heavy rains, colder temperatures, etc.
The female only lays her eggs on milkweed, the sole food source for the larva and caterpillar. She can lay up to 400 eggs one by one, generally at a rate of one egg per plant. Thus, reproduction requires a lot of energy. Besides to the chance of coming across a field of milkweed, it will take a lot of wingbeats to ensure the survival of the species in a context where milkweed is less present. Especially since the survival rate of the monarch from birth is only 1%. For example, most of the eggs and larvae being eaten by other insects. (Note that it has been observed that two generations of monarchs are born per migration.)
With all the difficulties encountered, the monarch is unable to increase the size of its colonies to reach a threshold of 4 to 5 hectares and thus reverse the trend to ensure the conservation of the species. It is necessary to act and help it all together, in urban and agricultural environments, by ensuring it has a sufficient number of healthy habitats.
The umbrella effect
Protecting the monarch butterfly also contributes to the survival of several other essential pollinators. Its widespread popularity encourages restoration and preservation efforts that indirectly contribute to other, lesser-known species. Pollinators are essential for food production and the balance of natural ecosystems, of which we are also a part and must contribute positively.
Marie-Noël Breton
Entrepreneure agricole, passionnée par la diversité florale et la pollinisation, Marie-Noël Breton a la fibre de l’innovation ! Membre de la coopérative depuis 2017 et aujourd'hui chargée de projet, elle a pour objectifs de promouvoir cette fibre locale aux propriétés exceptionnelles et rassembler les industries québécoises dans ce projet unique au monde !
