A Peculiar Feeding Habit of the Short-Billed Gull
A Peculiar Feeding Habit of the Short-billed Gull
On several occasions during the past season (February 6, 15; March 2 and 3, 1933), I have observed Short-billed Gulls (Larus canus brachyrhynchus) obtaining food in shallow water of the lagoon at the mouth of the Carmel River, California, in a manner which I have never seen described before.
When the sand bar dividing the lagoon from the sea has been opened up, frequently by artificial means, a large area of coarse sand, with shallow river channels winding through it, is exposed where previously lay the pent up river water augmented by winter rains. In these rivulets, or in certain parts of the flats where a small bit of still water has been cut off from the flowing courses, I have seen both adult and immature birds standing in an inch or two of water and briskly paddling their webbed feet up and down alternately, then stopping to peck lightly at the surface of the water thus stirred up from the bottom. Sometimes they will paddle and peck at the same time. The process apparently serves a purpose similar to the whirling of the Northern Phalarope (Lobipes lobatus).
Once I saw a bird feeding in this fashion in a shallow water course leading out of the meadow bordering the lagoon where the bottom was quite muddy, but the other occasions have been where there was a coarse, sandy bottom. Seven individuals on February 6 were seen to indulge in this activity simultaneously. It was in this same rivulet draining the marsh, but at a point farther down stream where the water was flowing over sand.
On two occasions I have watched a Coot (Fulica americana) walking behind a Short-billed Gull to peck at the surface where the latter had been paddling. Once the Coot made a pass with its bill at the gull to drive it away from such a place.
Laid-Law Williams
Carmel, California, May 1, 1933
