Mixed-flock Feeding Conflict

Micro Story: No Free Lunch

A solitary marbled godwit, likely seeking protection from predators, sauntered to the edge of the whimbrel flock and brazenly set about feeding. The whimbrels, who were preparing for a long migration, viewed the recent arrival as a competitor for a limited food source and monitored the godwit’s every move. 

When the godwit caught a crab, one whimbrel charged. The godwit, forced to flee, tossed the crab into the air, hoping to re-catch the crab at the base of its mouth. The flying crab clanked off the side of the godwit’s bill and fell into a mass of sea foam and stranded Velella velella bodies.

A frustrated godwit watched as the whimbrel enjoyed an easy meal. Bullying was the price of protection.

Field Notes

Marbled godwits and whimbrels frequently engage in mixed-flock feeding. However, this flock of whimbrels is a little less tolerant than most. Part of the reason for that intolerance is likely the oncoming migration season, as mentioned in the story, but I believe the size of the whimbrel flock also played a role.

The whimbrel flock contained 14 individuals at its peak, which may approach the limit of mole crab-eating birds that this stretch of beach can support.

Interestingly, this same whimbrel flock had a confrontation with a group of marbled godwits only a month earlier (see story here). So, this group has a history of rejecting marbled godwits from their feeding territory.

Updates

Project Update:

After following a trio of red fox cubs for much of the spring and early summer, I’ve started preparing the final outputs of the project. At this point, I expect to publish a photo essay on my website and may expand the printed output to include a zine or a photo book. Stay tuned. 

Behavioral Story:

A surfbird faces a dilemma when a second bird arrives ahead of a wave. Read more here.