Monarchs at Risk

Monarchs face many risks that are resulting in declining populations in both the eastern and western parts of their North American range. The largest impacts come from the loss of habitat for breeding, migrating, and overwintering. In addition, pesticides that are used to control insects and weeds have harmful unintended consequences for monarchs, a changing climate may be making some habitat less suitable and forcing changes in migratory patterns, and monarchs face many risks from natural enemies, such as predators, parasitoids, and diseases.

Breeding Habitat Loss

The loss of breeding habitat through much of the United States has strongly influenced the decline in overwintering monarch population.

Overwintering Habitat Loss

Conservation and management actions are needed to ensure the future of overwintering habitats for monarchs in California and Mexico.

Climate Change

Climate change models suggest that changes in the monarch migration and breeding range may force monarchs to change their migratory patterns.


Beneficial insects like monarchs and other pollinators can be negatively affected by the use of pesticides to control unwanted insect and plant species.

Natural Enemies

Despite the fact that toxins from milkweed may in some ways protect them, monarchs of all life stages are vulnerable to predation and disease.

Other Anthropogenic Concerns

Wise management practices are essential in providing long-term habitat for monarchs and other wildlife, but if appropriate guidelines are not followed, monarchs and other organisms using the site could be harmed.