Different migration schedules for the sexes

Male ducks don’t do much parental care, so they molt earlier than females and are ready to migrate south earlier than females.

For shorebirds, like this yellowlegs, females lay the eggs, but males incubate and care for the young.

We see lots of yellowlegs in the PPR starting in July, but most are the females that arrive early to molt; adult males and the kids show up later.