Vol. 45, No. 5
David M. Larson
Herring Gull with clam. Photograph by Andrew Cannizzaro (CC BY 2.0).
Anyone who lives along our coast has seen the phenomenon—gulls find a clam, fly up, drop their prey, and swoop down to retrieve the edibles from the usually shattered bivalve. But haven’t you wondered, “How did they figure that out?” and “Did they learn that technique or is it innate?”
There is considerable literature on feeding behavior in gulls, including The Herring Gull’s World by Niko Tinbergen (1953), one of the true classics of bird behavioral studies. As one might expect, juvenile gulls are less efficient at foraging and feeding than are adults. Juveniles may be less skilled at picking feeding areas, may be kept away from high-quality feeding areas by adults, may be less able to discriminate optimal prey items, or may be less efficient at foraging due to inexperience or physical or social deficits. Large gulls are identifiable in age class until reaching maturity at four years, so age-related changes in foraging have been well documented. Recently, Cristol et al. (2017) reported on their studies into the reasons for age-related foraging differences in American Herring Gulls (Larus argentatus) feeding on Atlantic rangia wedge clams (Rangia cuneata), primarily in a shallow coastal estuary in Virginia. Follow-up observations were conducted at a boat landing on Chesapeake Bay.
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What we learn from the survey responses, collected throughout spring and summer of 2017, will help us develop educational materials that build on birders familiarity with conservation issues, and that are relevant to birders current levels of engagement with certain conservation actions. By taking this survey, you will help us to develop materials that will be effective and applicable to fellow birders.
Registration is now open for Mass Audubon’s 2018 Birders Meeting. This year’s theme is:
The Birders Meeting will feature the ecology of these two habitat types and their significance to birds and birders.
Speakers include Dr. Sara Morris, Keenan Yakola, Kent McFarland, Chris Rimmer, and Dr. Jeff Wells. There will also be a special presentation by Victor Emanuel, founder of Victor Emanuel Nature Tours (VENT), and short updates about some of Mass Audubon’s current bird conservation work.
The meeting will include lunch, raffles, exhibits, book-signings, and a wide variety of vendors. This promises to be an outstanding event.
More information and registration
Bird Observer is collaborating with the Association of Massachusetts Bird Clubs to bring together birders from across Massachusetts to communicate more effectively, share ideas, and take unified action to support bird conservation. The Association will hold its next meeting from 10:00 to 12:30 on Sunday, April 15 at the Mass Fish and Wildlife office at Westborough WMA. If you belong to any of the 18 member clubs in the Association, you are welcome to attend and participate in this meeting. For more information contact John Nelson at firstname.lastname@example.org.