EPOW - Ecology Picture of the Week

The Gull That Is and Isn't A Dolphin

Dolphin Gull (Leucophaeus scoresbii), Family Laridae
Strait of Magellan, Punta Arenas, Chile

Explanation:  Quick!  Can you find the dolphin in this photo?

Yup, it's a trick question.  The three smaller birds in front are dolphin gulls, found here on the southern edge of Chile in the "Southern Cone" of South America.  We are in Punta Arenas and, more specifically, the Strait of Magellan.  Behind them -- for size comparison, here -- lurk several kelp gulls (Larus dominicanus), also a fairly common resident of these coastal shores.  

Dolphin gulls bear a superficial resemblance to red-billed gulls (Chroicocephalus novaehollandiae) and silver gulls (Chroicocephalus novaehollandiae), both found in Australasia and New Zealand, but these two look-alikes belong to an entirely different genus than the dolphin gull despite the apparent similarities and small body size.  

Dolphin gulls, like other gull species, are scavengers and opportunistic feeders.  One study found them frequenting either a mussel bed or feeding at a seabird and seal colony site, and individual dolphin gulls seemed habituated and specialized for their specific feeding site.  

Information:
     Masello, J.F., M. Wikelski, C.C. Voigt, and P. Quillfeldt.  2013.  Distribution patterns predict individual specialization in the diet of dolphin gulls.  PLoS ONE 8(7):e67714.  https://doi.org/10.1371/journal.pone.0067714