A whimbrel chick never really gets to know its mother. Soon after their eggs hatch, the females take off from the breeding grounds in the far north, leaving the males to care for the juveniles. The daddy whimbrels migrate after the chicks get to fledgling age. The young of the year, “basically migrate on their own,” biologist Fletcher Smith says, embarking on a danger-filled trip over thousands of miles without any experienced birds to lead the way.
“One of the findings of this study is that the birds seem to have a road map within their DNA that they’re following,” Center for Conservation Biology Director Bryan Watts said. “But what’s been so incredible about these birds is their ability to adjust to the contingencies along the way.”
The birds need the ability to fly by the seat of their pants to survive the vicissitudes of trip. The fall migration of whimbrels occurs during Atlantic hurricane season and many birds have displayed savvy adjustments in itinerary in response to meteorological conditions. Some whimbrels have dodged storms, while others (like some of the birds this year) adjust their routes to take advantage of trade winds.
“All our transmitters have been put on adult birds that have likely made a migration several times in their life already,” Smith says. Tracking reveals that individuals among these birds use different migratory strategies, as well.
“It’s an interesting point,” Watts said. “Selection has both built a broad road map that guides these birds over long distances and provided the flexibility for birds to make detours when necessary.”