Summary of the Fort Belvoir CBC, Dec 30, 2018 (circle center on Rt 1 near
Pohick Church in Fairfax Co.)
The count recorded 108 species and one count week species (Lesser
Black-backed Gull) due to the efforts of 174 field counters (63 parties) and
16 feeder watchers - this is bit below the long-term average of 113 species.
There was one unusual species, Clay-colored Sparrow. Species with High
Counts were Double-crested Cormorant (349), Blue Jay (1746), Red-breasted
Nuthatch (98), Gray Catbird (10), and Swamp Sparrow (319). Species with Low
Counts were House Finch (111). Uncommon species were Greater Scaup (only
2), Common Loon (2), King Rail (2), Greater Yellowlegs (2), Wilson's Snipe
(only 1), American Woodcock (8), the 3 typical owls, American Kestrel (1),
Merlin (2), Peregrine Falcon (1), Common Raven (2), Palm Warbler (1),
American Tree Sparrow (6), White-crowned Sparrow (12), Lincoln's Sparrow
(2), Purple Finch (8), and Pine Siskin (7). I note that American Coot was
almost a low count (7) as well as American Goldfinch (250). After
deconfliction, Bald Eagle numbers were 156 (116 adult).
This winter season had low overall numbers of waterfowl (although all the
typical species were reported), which is thought to be due to the rainy
summer causing high water levels and turbidity and thus lowering submerged
aquatic vegetation growth as well as reduced underwater animal production.
Chickadees (732) and Titmice (731) were low, but not record low, and this
may also be associated with the effects of the wet summer. Moreover, Great
Blue Heron tallies (182) were depressed this year, also possibly related to
the wet summer. Additionally, House Finch and American Goldfinch were also
depressed in numbers, although the impact of disease on the former may be
key to understanding its decline. We note the fall had a poor berry crop
showing for some plant species, e.g., poison ivy, which greatly reduced
warbler (YWRA=19) and waxwing (393) totals.
On the other hand, the significant autumn influx from the north of
Red-breasted Nuthatches was notable and produced a record count.
Unfortunately, this did not extend to the other winter finches, which,
despite a great fall migratory showing, were present in limited numbers in
the circle. A good migratory season coupled with desirable habitat led to
good sapsucker (91), creeper (86), winter wren (53) and Hermit Thrush (125)
numbers. Overall, sparrow numbers appeared to be a bit higher than average,
but not in record numbers (except for SWSP). This year we had 2 Lincoln
Sparrow reports and when one notes that over the last 20 years LISP is
sometimes reported for this circle suggests a new wintering trend. With the
inclusion of the Lorton Landfill and Laurel Hill Parks, good habitat for
species that are problematic elsewhere in the circle can be surveyed and
this enhances harrier, kestrel, meadowlark and White-crowned Sparrow
tallies. Continued maintenance of these habitats should result in the
continued presence of these species in future counts. Notable was the return
of the Clay-colored Sparrow to the Laurel Hill Eq. Center Park after giving
a fine showing last winter. Although the CCSP was a bit more elusive this
season than last, it still has delighted many birders.
Some long-term trends are beginning to become apparent. Vultures and
cormorants have increased greatly in numbers compared to just 20 years ago -
this may be connected to long term warming trends. Another trend is the
switch of buteo abundance from Red-tailed Hawk to Red-shouldered about 14
years ago which is likely due to the increase in the suburban landscape
footprint.
Additional notes on count data: wind direction was variable the day of the
count, but strength was weak throughout the day. Some field counters became
feeder watchers in the afternoon, hence the numbers have some overlap as the
total participants numbered 185.
Last, but not least, a special Thank You to the Sector Leaders and ALL the
Counters who have, once again, made this CBC excellent!
Wishing You All Good Birds,
Kurt
