Slaty-back on Saturday
Dma3@aol.com
Sat, 13 Feb 1999 20:16:56 EST
The Conowingo Slaty-back was watched on Saturday about 3-4PM Standing and
swimming among the rocks near the end of the "seawall." It may have been seen
briefly in flight shortly after 7AM when masses of gulls flushed, some landing
behind the seawall, some flying away.
It indeed a tricky bird to pick out. The mantle is barely paler than that of
Lesser Black-back, and more slate, with no brownish hints, but in some lights
they will look similar. It is larger and more heavily built than Lesser, with
stronger head, slightly thicker bill. There is only a hint of head streaking
at this point, faint streaks on crown and nape and smudge outlining eye, but
many Lessers are already in their prealternate molt, and losing their head
streaks rapidly.
Please make every effort to study the primary pattern of the bird if it
preens, and get flight photos if it moves in to feed. This information will be
vital in eliminating other species and hybrids. With gulls like this, it is
very hard to get from being 99% certain to being 100% certain.
Dave Czaplak