Monarchs Move North

Monarch Butterfly

Monarch Butterflies have left their overwintering site in Mexico and are now reaching Texas. The good news is the warm and rainy weather in Texas this year has produced large numbers of flowering plants that are sources of nectar and abundant milkweeds already sprouting. Texas is considered especially important to Monarchs as the first available habitat on their journey north. The bad news is that warmer than usual temperatures in Mexico raises the metabolism of the overwintering butterflies and more rapidly depletes their reserves.

Despite their low overwintering numbers, Monarch populations can rapidly expand given the right environmental conditions. Abundant food, milkweeds for the caterpillars and nectar for the adults are part of those conditions. The declines in Monarch population this century are correlated with reduction in milkweed plants in agricultural fields. Milkweed reduction does not eliminate other factors in Monarch decline. Further study may identify other important factors such as climate or other environmental changes. Hopefully conditions will be good this year for a population rebound.