Researchers are calling on the public to report monarch butterfly sightings in eight southern and Gulf states to try to better understand the insect’s migration and wintering behavior.

The Georgia Department of Natural Resources announced the effort on Thursday. Scientists want to hear about sightings from December 1 to March 1 in North Carolina, South Carolina, Georgia, Florida, Alabama, Mississippi, Louisiana and Texas. The observations should be reported at journeynorth.org.

The information may help conservation efforts by determining if the butterflies can spend the winter as non-breeding adults in the southern U.S., Sonia Altizer, an ecology professor at the University of Georgia, said in a news release.

It could also shed light on how breeding during the winter may be affecting the butterfly’s annual migration to Mexico.

Monarch populations have declined significantly over the past two decades. Last year, the insect became a candidate for listing under the Endangered Species Act.

Monarchs in the eastern U.S. and Canada generally stream across the South each fall on their way to wintering grounds in central Mexico. They then return in the spring to breed. But a similar reporting effort last winter led to more than 5,800 observations of monarch butterflies in southern and Gulf states, according to the Georgia Department of Natural Resources.