TAGGING STUDIES

An important first step in bringing aid to the Monarch in its migration is to determine with precision where its migratory corridors are located from different geographic locations in the United States. We are currently in a multi-year study to determine these migratory corridors from Southeast Idaho. Do Monarchs travel from there to various overwintering locations along the coast of California, or do they travel into the overwintering locations high in Mexico, or both? As yet, we do not know with certainty. Once we have a better understanding of these migratory corridors, we can marshal efforts to populate these migratory corridors with milkweed for hosting eggs and caterpillar development, and spring and fall flowering nectar plants for an adult food supply during migration.

RESEARCH PROJECTS

Once numbering in the millions in the Western United States as recently as the 1990s, Monarch populations have declined precipitously in recent decades ever since introduction of neonicotinoid insecticides were introduced broadly into farming practices in America. As recent as 2020, there was only 1,899 Monarchs counted in the overwintering sites along the coast of California. This set off alarms and cries of an inevitable death spiral into extinction for the Monarch among many well-meaning individuals and groups, as many biologists worried that the Monarch had already passed below the level of biological sustainability. 

Fortunately, further research has suggested that because of the higher regional temperatures in California in 2020, the migrating Monarch populations adjusted their typical overwintering locations to include inland locations as well, in the California Bay Area among others. In the subsequent years of 2021 and 2022, as temperatures returned to historical norms, the overwintering Monarch populations have returned to around 300,000 levels.

Nevertheless, there does appear to be a strong correlation between the introduction and use of neonicotinoid pesticides in the mid-1990s onward and the precipitous decline in Monarch populations since then. Other major factors, like climate change and loss of habitat, are other major factors in this decline, but additional research into the effect of neonicotinoids on all beneficial insect populations is urgently needed.