Surf birds at Cape Hatteras
June 28th, 2012
Laughing Gull, wallpaper available
Boat-Tailed Grackles are crow-sized blackbirds adapted to a coastal lifestyle.
Of the various songbirds on Hatteras, few of them show up on the outer
beaches. Boat-Tailed Grackles are a notable exception. They forage at the edge
of the surf, digging for small invertebrates. This week they were fattening
themselves on mole crabs (a.k.a. sand bugs), little beetle-shaped crabs that
burrow in wet sand. When coquina clams (another burrower at surf edges) are
abundant, they'll eat those, using their beaks like nutcrackers.
When a wave washes in, they leap and flutter to keep their balance.
I was mildly surprised to find this Black-Bellied Plover flying over the surf
The lifestyles of shorebirds are a mystery to me. They have a very short
nesting season--I know that much. So shorebird "spring" migration carries on
into early June, and "fall" migration starts in July. But you'd think that in
mid-late June, these birds would be ensconced on their breeding grounds.
And it just isn't necessarily so. I saw nine different species of shorebirds
on this trip, and only two breed anywhere in the vicinity. The rest of them
are birds of the west or the arctic tundra. And this isn't considered unusual.
Black-Bellied Plovers never rate anything below "uncommon" at any time of the
year on the Outer Banks.
Field guides aren't much help with these questions. My tentative hypothesis
based on internet research is that this is a failed breeder. Apparently, when
a bird fails to find a mate or is otherwise stymied in its attempt to breed,
it may immediately head back to its wintering grounds, doing an early molt on
the way. I guess there's no point in enduring the rigors of the tundra when no
fruit is going to come of it this year.