Journal of a Sabbatical

April 13, 2000

gull economics

Plum Island Hawk Watch

Plover Warden South
11:30 AM - 3:30 PM
low tide
no piping plovers
no dogs
8 visitors

Today's Bird Sightings:
Plum Island
3 American kestrels
1 northern flicker
1 northern mockingbird
1 purple finch
2 great black back gulls
31 herring gulls
11 brant
11 double crested cormorants
1 common loon
2 redwing blackbirds
2 killdeer
5 American robins
314 Canada geese
6 gadwalls

Today's Reading: Thoreau's Country by David R. Foster, Uttermost Part of the Earth by E. Lucas Bridges, Cat on the Scent by Rita Mae Brown

Today's Starting Pitcher:
Pete Shourek

Herring gulls seem to be all over the place this morning. Low tide is extremely low today leaving the rocks with their encrustation of mollusks exposed. A flock of about 30 or so gulls is taking full advantage of this food bonanza, smashing clams and mussels on the rocks. A walk among the tide pools also reveals a fair number of freshly killed sea urchins - well, their remains - the detritus of the herring gull sushi bar. The gulls clearly have no idea what they'd be paying for those delicate morsels in Tokyo's finest restaurants.

One immature gull keeps dropping the same mussel into soft wet sand over and over, clearly getting frustrated that it's not breaking open. How do they learn what surface is hard enough to break the shells? Finally it hits a rocky patch, splits open, and is devoured in like 3 seconds.

Two first year gulls engage in aerial combat over some kind of bivalve. One has it in its beak and dodges attacks from the other who either tries to grab it from below or knock it out of its beak. The attacker turns over in midair and rams the possessor with its feet, almost as if the deluded gull thought it had talons instead of webbed gull feet! They looked for a second like hawks locking talons! Chase. Collide. Chase. Collide. This goes on for quite some time. A third gull, also first winter, joins in the chase. The amount of gull energy being expended in pursuit of this one tiny bivalve has got to be way in excess of the number of calories the food would provide to the winner. Finally the possessor plummets toward the water, almost like a gannet, with the other two in pursuit, and drops the edible morsel into the sea! Total time of this drama: seven minutes!

Clearly the juvenile gulls need a lesson in gull economics!

Two small flocks of brant seem to have divided the territory between them, one at Emerson Rocks and one at the rock pile on the state beach. No fights about sea lettuce break out. Several brant walk up on the beach or perch on rocks and preen themselves. It's novel to see them on land resting and preening instead of gorging on sea lettuce or flying en masse. Almost like this low tide was a vacation for the brant.

With the tide so low, all the sea ducks are way too far out for identification. They look like black and white dots through binoculars. They're invisible to the naked eye.

For the first three hours of the shift everything is quiet, no people, no dogs, nothing. No piping plovers are in evidence although four pairs have been reported, and another pair at Sandy Point. Early in the season, plover warden duty mainly seems to involve explaining that even though the plovers are invisible, the beach is closed.

Near the end of the shift, vast hordes of visitors to the state park arrived. Most of them simply turned right off the trail and walked down toward Sandy Point. A few came over and asked about the beach closure then went on their way south with no fuss. One guy who'd recently moved to Newburyport wanted to know all about being a plover warden and whether we still needed volunteers.

The last hour went by very quickly.

The drive back to the gatehouse took awhile with constant stopping to look at kestrels hovering over the south field, or perched on trees, their gorgeous coppery backs and light blue wings gleaming in the sun.

There were five hawk watch people in parking lot 1 today so those kestrels surely got counted on their way north.