Marbled Murrelets (Brachyramphus marmoratus) foraging with gray whales (Eschrichtius robustus) off Vancouver Island, British Columbia

Abstract

Seabirds are known to associate with marine mammals to facilitate prey capture. These occur when mammals either force prey near the surface or provide small scraps of larger prey victims. Gray whales (Eschrichtius robustus (Lilljeborg, 1861)) have been observed to provide invertebrate prey to a variety of seabird species; however, there are no published reports of Marbled Murrelets (Brachyramphus marmoratus (Gmelin, 1789)) feeding in association with gray whales. We observed Marbled Murrelets foraging within several metres of gray whales off Vancouver Island, British Columbia, feeding on epibenthic zooplankton in 2006 and 2008. Join-count statistics identified significant clustering (p = 0.1) of 258 Marbled Murrelets within 300 m of 39 feeding gray whales in June of 2006, and no association between 3 gray whales and 34 Marbled Murrelets in June and July of 2008, marking a foraging association conditional on the abundance of both gray whales and their prey, but potentially significant to Marbled Murrelet survival and fecundity.