a committee of the New York State Ornithological Association
of New York Rarities
by Angus Wilson, Photographs by Andy Guthrie
Late in the afternoon on Sunday 31st January 1999,
Andy Guthrie and I discovered an adult Black-tailed
Gull (Larus crassirostris) roosting in a flock
of Ring-billed Gulls (Larus delawarensis) near Parking Field
#6 at Jones Beach on the south shore of Long Island, New York.
To the best of our knowledge, this represents the first state record
of this asiatic species.
Figure 1. We
first spotted the bird as it stood with a group of roosting Ring-billed
Gulls on the sand separating the parking field from the ocean.
Although resembling a Lesser Black-backed Gull, the bird appeared
only slightly larger than the surrounding Ring-billed Gulls.
Figure 2. The
deep red orbital ring and bright yellow iris are clearly
visible. The bill was yellow with a broad subterminal band
crossing both mandibles. The bill was tipped with red and
on the lower mandible there was a patch of red (gonyl spot)
on the distal side of the black band. In life, the mantle
was a uniform slate gray (lighter than in these photos) and
without any hint of brown. Five white primary tips were visible
on the folded wings. On the standing bird we counted three
primary tips (P8-P10) beyond the end of the tail, with the
next primary tip (P7) parallel with the tail tip. One additional
primary (P6) carried a white tip. The white tips appeared
larger and more striking in life than they do here.
Figure 3. Taking
flight. The bold white rump (uppertail coverts) contrasted
dramatically with the broad black subterminal band on the
tail. This immaculate black band was approximately one bill
length deep and stretched across all of the tail feathers
except the outermost which appeared all white. The white
terminal band was perhaps one third to one quarter the width
of the black subterminal band. The yellow legs are clearly
visible here. Note also the neat white trailing edge to the
secondaries and inner primaries.
Figure 4. More detail
of the tail. Notice how the black of the subterminal tail
band extends along the outer webs of the tail feathers towards
their base. The prominent white primary tips and the obvious
contrast between the black outer primaries and gray inner
primaries/secondaries/mantle are not evident in this exposure.
Figure 5. Closer view
of the standing bird showing the diagnostic bill pattern,
yellow iris, red orbital ring, yellow legs, subterminal black
tail band and white primary tips.
raised showing the dull gray undersides.
Figure 7. Detail
of the subterminal black tail band as the standing bird
raises its wings.
Figure 8. More
detail of the tail. This time we can see the undersides
of the tail feathers.
Exciting images of a 3rd basic Black-tailed Gull from Texas can
be found here: