A new study from The Auk: Ornithological Advances shows how pairs of Common murres update each other on their condition so that when one partner needs a break, the other
can pick up the slack. Common murre parents trade duties throughout the day — one stays at the nest while the other leaves to forage, hopefully coming back with a fish for the chick. Because brooding the chick requires much less energy than foraging, staying at the nest is preferable for a bird that’s in poor condition. The researchers observed 16 pairs of murres with chicks on an island off the coast of Newfoundland in summer 2009, recording their behaviour when parents switched duties at the nest and capturing the birds to check their body condition. Their results show that these “nest relief” interactions take longer when one partner is especially low in body mass, suggesting that when brooders withhold preening and stall their departure, they’re letting their mates know that they need more time to rest; the returning mate can then compensate by going off to forage again rather than trading places immediately.