Summary Fort Belvoir CBC, Jan 1, 2012
Warm weather up to and including count day affected tallies
for some species yet most others had normalized averages consistent with
historical trends; there are indications that waterfowl were reduced in
numbers but not at historical lows. The count tallied 114 species,
surprising given the date and the low turnout of field counters (139
counters, lowest since CBC 100, Jan. 2, 2000 which had 134).
Highlights were:
Unusual Species observed in less than 5 of the last 20 years:
Cackling Goose, Veteran's Park, Woodbridge, this will become less than
unusual as the years go by due to the elevation of Cackling Goose to species
status and since 1K to 2K flocks of Canada Geese near the Potomac River
often contain a Cackling Goose
Virginia Rail, 4 out of 20 years, Huntley Meadows, present for some time
Common Raven 4 out of 20, Huntley and the Lorton area; clearly CBC frequency
is increasing
Orange-crowned Warbler, 3 out of 20, Occoquan Bay NWR, very close to the
Brewer's Sparrow!
Brewer's Sparrow, new to count and new to Virginia, and Occoquan Bay NWR; an
amazing bird! Special Thank You to Linda Chittum, Russ Taylor, Phil Kenney
and Phil Silas
Hard to find in the circle during count day (recorded 6-10 times in the last
20 yrs):
Great Egret (an amazing story with wide-ranging No. Va observations from
December, 2011 to February, 2012; for instance, try Huntley Meadows),
Peregrine Falcon (at Occ. Bay NWR), and Lesser Yellowlegs (Great Marsh of
Mason Neck).
Species not too regular in the circle but you can probably find somewhere
nearby-ish (11-15 times in 20 yrs):
Snow Goose (Blue Phase, Veteran's Park), Horned Grebe (in decline, Pohick
Bay and the Colonial Farms Md area), Merlin (Huntley Meadows), King Rail
(Occ. Bay NWR, present for some time), House Wren (surprisingly hard to find
probably because it's so quiet in the winter in our circle - try the
Hallowing Point area, Mason Neck), Common Yellowthroat (Occ. Bay NWR and
Colonial Farms area), Chipping Sparrow (typically not an easy species to
find except for this year with a flock of 17 in the Gunston area and also
one at Occ. Bay NWR).
And then the species that are more or less regular yet are targets for many
local birders:
Common Loon (Pohick Bay), DC Cormorant, Black Vulture (only present in the
count for 18 yrs and showing a steady year to year increase; this year an
astonishingly high count of 236! and... duplicates were eliminated!), Wild
Turkey (steadily increasing probably because the forest is maturing),
Greater Yellowlegs (Great Marsh of Mason Neck is the bastion), American
Woodcock (displaying, almost always found on count day, peak display period
is now to early March in our area), Bonaparte's and Laughing Gull (tough to
find as only a few are present in early January), Red-breasted Nuthatch
(surprising as it's not a migrant year for this species, but scattered
reports of 8 birds tallied; try Fort Belvoir trails that traverse near Pine
trees), Gray Catbird and Brown Thrasher (pockets here and there),
White-crowned Sparrow (the Huntley Meadows back country and Burke Lake area;
not easy to find), Rusty Blackbirds (Mason Neck near wooded marsh edges and
Occ. Bay NWR), Brown-headed Cowbirds (Mt Vernon, Mason Neck and Colonial
Farms areas), and Purple Finch (single in the Burke Lake area).
Other species that are of interest such as Wood Duck (big
numbers on count day at Jackson Abbott Refuge this year), Greater Scaup
(carefully work through the big scaup rafts), Red-headed WP (big
concentration along the Indian Head Rail Trail in Md sector plus one at
Huntley Meadows), Yellow-bellied Sapsuckers (everywhere in low density,
always forested), Winter Wren (everywhere in forest edges in low density,
you need to learn the call notes), Hermit Thrush (scattered in forests with
some conifers), American Tree Sparrows (Huntley Meadows, Gunston, Occ. Bay
NWR, Colonial Farms in appropriate habitat), Savannah Sp (most in the Burke
area, power line cuts and such, also a few in the backcountry of Huntley, 2
at Fort Belvoir, 2 in the Mason Neck fields, and one at OCBNWR) and single
Purple Finch in the Burke area.
Count week species were Long-tailed Duck on the Potomac just
before the count and Lesser Black-backed Gulls at Neabsco Creek the day
before.
High Count species were: Great Egret (6, warm weather!),
Black Vulture (236, warm weather), Turkey Vulture (289, warm weather), Wild
Turkey (69), Lesser Yellowlegs (12, Great Marsh of Mason Neck, amazing!),
and American Woodcock (21, warm weather must be playing a role!, reported at
Huntley, Ft Belvoir, Mason Neck, Occ Bay NWR, and Colonial Farms sector).
Low Count species were (low counts have rarely occurred
during my tenure as compiler): Bald Eagle ( 177 were reported to me - many
were already deleted! - and it was winnowed down to 85; given the warm
weather up north, a low count is expected), Herring Gull (418 - recent range
is 411 to 1324 - , second lowest in 20 yrs!; a poor gull year again
attributable to warm weather), Great Black-backed Gull (108; one year was
118 and all others above 200), Brown Creeper (26, ties previous low for CBC
104, 1/4/04), Golden-crowned Kinglet (44; previous lows were 49 - 1/4/98 -
and 56 - 1/2/00 - all others are 95 or greater!), Ruby-crowned Kinglet was
pretty low (25, lowest was 18 in 1/5/97), Northern Mockingbird (141, second
lowest), Eastern Meadowlark (1, never missed since at least 12/22/68, in a
power line cut behind a church and a great example why more field counters
are needed to cover all the habitats!) and House Finch (second lowest since
last year at 156, and next lowest is during the population boom in 12/23/84;
indications of recent population decrease).
We can use count data to evaluate the claim that waterfowl
counts are down. I am using absolute numbers as most of the key waterfowl
habitats are naturally covered irrespective of field counter turn out.
First, Canada Geese. Counts were about 10,000, down from about 13,000
averaged over the last 10 yrs (which shows an increase over a 20 year
interval) but this slightly depressed total may be due to natural variations
as well as the warm winter. For the balance of the waterfowl, I summed over
all species of ducks and got 19,251. The average for the last 20 yrs is
28,515 and the range is 18,148 to 54,748 (the variability is due to a range
of factors including production in the breeding areas, weather during count
day, and weather history leading up to count day); the count seems to
indicate that duck tallies are on the low side but not historically low -
again, this may be a result of the warm weather yet other factors could be
playing a role.
Finally, what are the trends for resident populations of
mainly non-migrant species? These species are Red-bellied WP, Downy WP,
Hairy WP, Pileated WP, Carolina Chickadee, Tufted Titmouse, White-breasted
Nuthatch, Carolina Wren, Northern Mockingbird, Northern Cardinal, House
Finch and House Sparrow. I examined the last 20 yrs of normalized data
(using field hours) and found that Pileated Woodpecker is down a bit but
this may be due to improperly eliminating duplicate tallies in prior counts,
Northern Mockingbird is really low and no explanation can be found, House
Finch has been showing signs of decline starting about 1/3/99 and
approximately reaching current normalized levels near 1/4/04 yet may still
be going downward, and lastly House Sparrow which is down by 38% yet it is
difficult to draw conclusions as this species probably does not get enough
serious attention on count day. All other resident species are close to
normalized count densities.
Lastly, the Audubon CBC website will display this year's and
prior year's counts. The website seems to be having some difficulties this
year but I think this will all be ironed out in the next few weeks (software
issues).
Again, a Big Thank You to Everyone Who Came Out and Counted!
Kurt Gaskill
Ft Belvoir compiler and data cruncher
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