Date: 4/30/18 8:07 pm From: kurtcapt87--- via VA-bird <va-bird...> Subject: [VA-bird] A Great Weekend for the VA Breeding Bird Atlas!
A Great Weekend for the VA Breeding Bird Atlas!
The weather and timing were great for doing a bit of Atlas-ing this past weekend. Typically, for the Northern Virginia area, the last weekend of April and the first week of May have the most species diversity. Yet, it is also a period where many species are setting up "house" or raising young. For these reasons I decided on a bit of Atlas-ing, especially the priority blocks which are essential for this project!
Saturday, I started off at Mason Neck SP and NWR in Fairfax Co. The Fort Belvoir SE priority block is doing quite well but deserves a few more probable or confirmed breeders. Plus, adjacent blocks such as Indian Head NW or Fort Belvoir SW (although not priority blocks) have excellent habitat possibilities for unusual species. I started pre-dawn and added a singing Eastern Screech Owl at the same spot as one nearly 2 weeks earlier - moving the species up to probable status for Indian Head NW. For the biologist who analyze the Va Breeding Bird Atlas, probable status is nearly as good as confirmed, which means moving a species into this category is desirable.
During the Screech stop, a Veery made a flight call along the Potomac - a fine migrant. And migrants would soon dominate the day. The next bird heard was a gurgling Wood Thrush - perhaps 45 minutes before sunrise. Later, Wood Thrush plus other birds sang throughout this day, yet none could be recorded for the Atlas (such as the Yellow-rumps, Ovenbirds, waterthrush, No. Parulas, Blue-headed Vireos, Red-eyed Vireos, White-throated Sparrows, other warblers, etc.) as these birds are migrants and I do not know if they will stay unless other breeding behavior is noted. The Atlas website has charts with guidelines on the "safe dates" for coding singing species, especially for those that migrate.
I made it to the Mason Neck NWR impoundment and it got interesting. Top bird was a Great Egret perched on the edge of the impoundment on a small tree or shrub. Eventually it flew into the heronry - one of the largest west of the Chesapeake Bay - and was lost in the trees. I coded it as appropriate habitat as in years past Great Egrets were breeders, but I will have to take a closer look to find confirmation.
The next interesting sighting was a yodeling Pied-billed Grebe - a common call to the north such as in Minnesota or Maine but decidedly unusual in Northern VA. I will need to look more carefully for this species on my next visit.
There were other goodies such as Red-eyed Vireos, both orioles, some Common Loons off in the bay, a male Wood Duck floating nearby in the bay (waiting expectantly?), American Coot and Ring-billed Duck.
I continued my trek through the NWR and adjacent SP lands and recorded species via blocks. Top Atlas bird was a Black Vulture nesting in an old greenhouse in SP land. I upgraded Red-shouldered Hawk to a pair on Sycamore Rd in the Ft Belvoir SE block. Unusual migrant was a late Winter Wren. Totals for the day were good, despite the fog limiting distant viewing (for the diver ducks only Lesser Scaup and Ruddy Duck were found). 84 species were tallied by noon including 15 warbler species. Top numbers were Yellow-rumps (37), No. Parula (27), Ovenbird (16), Common Yellowthroat (6), Pine (4), Yellow-throated (3), Black & White (2), Prothonotary (2) and singles of Worm-eating, LA Waterthrush, Blue-winged, Magnolia, Yellow, Black-throated Blue, and Prairie. The vireos were good with 20 Red-eyes noted plus 6 Yellow-throateds and 2 White-eyes. Great Crested Flycatchers totaled 10, Wood Thrush topped out at 18, Scarlet Tanagers were 4, and White-throated Sparrows were obvious with 54 noted. Only 2 Swamps and 1 Song Sparrow. Orchard (5) beat Baltimore Orioles (2). At the end of the day 2 Indigo Buntings were near the VC.
Sunday, Rich Rieger joined me for a foray to the Widewater CW priority block, in Stafford Co. Although becoming a tad more suburban, it still retains some wild character, especially near the new State Park. The gravel Brent Pt road through a forested valley stretch from the northern block boundary was very good as we chanced upon a Barred Owl near the roadside. Knowing it was likely watching a nest site, we found the nest in just 2 minutes, in a snag cavity very close to the road, and it held a young owlet peering at us. Afterwards, we continued down the road, tallying what we could.
Past the railroad tracks we got a bit of luck and managed to confirm Chickadee, Titmouse, Red-bellied, and Hairy WP. Plus, an Osprey nest and a Purple Martin house in business. The process we use is straight-forward - we tally birds in safe date range that are present or singing. We look for other behavior that indicates a higher code - like this male and female No. Parula moving together from tree to tree in a tight area - clearly a pair. With this approach, our codes for singers, "S", become available for consideration during a future visit 7 or more days later. Then, when we find a singer at the same spot during safe date range, we can consider upgrading to the "S7" code - making that species a probable breeder and very valuable to subsequent data analysis by the biologists.
Regarding migrants, the day at Widewater CW was reasonably productive with a dozen warbler species where Yellow-rump (38), Ovenbird (13), No. Parula (13), LA Waterthrush (5), and Yellow-throated Warbler (4) were tally leaders. Curiously, only 9 White-throated Sparrows were found but Wood Thrush was good at 11 tallies. We managed to find 2 each of Yellow-throated and Blue-headed Vireos. And our work added 6 more confirms for the block plus 4 more probable species.
Despite not trying for a big weekend species total, I still tallied 98 for the 2-day stretch. Which means that Atlas-ing has few benefits!
PS if you see a daylight owl, be sure to add it to the Atlas as "H", in appropriate habitat (unless it does something else.). This will be most valuable to the Atlas. Thanks!