Glaucous Gull Predation on Dovekies: Three New Hunting Methods

Abstract

We describe three previously unreported methods that hunting glaucous gulls (Larus hyperboreus) use to capture nesting and fledgling dovekies (Alle alle). During the nesting period, the pale-gray and white gulls camouflaged themselves by perching with head lowered on remnant snow patches in the dovekie colony, trying to ambush flying adults. We observed two other glaucous gull hunting methods on the open fjord water after the dovekie fledglings had left the colony. Gulls approached young dovekies in a fast, low-level glide, presumably to surprise the prey, and attempted to snatch them from the water. Gulls also swam rapidly towards young dovekies, zigzagging among small ice floes, presumably to confuse the birds and catch them before they could dive. The methods described, representing technical foraging innovations, supplement the evidence that gulls are a bird family that displays a diverse foraging innovation repertoire.