overwinter

Threats to the monarchs include the loss and degradation of habitat used for breeding, migration and overwintering, including milkweed plants they rely on as a place to lay their eggs.

When it’s chilly, they chill out to conserve energy — going into a type of insect hibernation called overwintering, Gonzalez said.

"The DNA analysis has now proved they are overwintering - they could get really established here," Ms Ingram said.

But for overwintering pollinators, leaf litter and dead branches are shelter and nesting sites.

Some of the refuge is only open from March 1 to September 30, to protect overwintering waterfowl.