Thursday, February 15, 2018

A Gull's View of Gannets


Gannets soar eye to eye with gulls, searching out schools of fish. Their bright white silhouettes pointed at front and rear, long tapering wings at the middle of the body, and stiffer flight mechanics distinguish them from gulls. The 5 to 6 foot wingspan helps them glide efficiently for a life at sea, ranging seasonally from the North Atlantic to the tropics.

During their fall migration moving south past Cape Ann gannets use the prevailing winds to circle around Massachusetts Bay. Their peregrinations bring some of them close enough to Halibut Point for us to witness their spectacular fishing methods from shore. Eyes set far forward close to the beak afford them better binocular vision than most birds, for calculating distances and pinpointing prey.


A gannet will plunge-dive from heights over one hundred feet to surprise fish under water. Air sacs within special bone structures absorb the surface impact. Its nostrils are located protectively inside the beak.


As it nears the water a gannet takes on an increasingly ballistic shape, wings reduced to aerodynamic guidance fins, muscle mass pulled in tight. It hits the water in an arrow-like profile with a minimal splash as aspired to by Olympic divers.


The gannet propels itself to chase fish with webbed feet and 'rowing' wings. It usually swallows its prize before surfacing. Gulls may be waiting to take advantage of its fishing prowess in depths that they cannot reach. 

Gannet hastily swallowing a fish
Here in New England we are at the northern edge of the gannet's winter distribution. Next month the population will begin migrating back to nesting sites on rocky islands and inaccessible cliffs of the North Atlantic rim, all under the close eye of gulls.

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