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DVOC Field Trip Report
by Steve Kacir

March 21, 2009
DVOC Field Trip and DE Breeding Bird Atlas census at Bombay Hook NWR

On the morning of March 21, I got a somewhat later start than I’d planned for arriving at the refuge, but still made it there with plenty of time to do a slow drive in on Whitehall Neck Rd. There were no signs of Snow Buntings, only a few Horned Larks, and none of the larks were exhibiting breeding behavior. One of the goals I’d set for the trip was to confirm Horned Lark as a breeder in my Breeding Bird Atlas Block: Woodland Beach SW or Block #62, which encompasses a fair amount of the publicly accessible areas of Bombay Hook NWR. I was hoping to find some potential nesting Horned Larks on the drive in, and then bring the field trip participants back to those sites. Unfortunately, I just had no luck finding any larks exhibiting breeding behavior. I did get to see the female American Kestrel perched on the wire just in block #62 as usual.

Presently, Cindy Ahern pulled up behind my Scion xB and followed me in to the visitor center. There I met up with John and Peggy McDevit, Cindy Ahern and her son Eric, and Stew Beltz and his son Jack. We took a quick moment for everyone to get prepared for birding. Then we began exploring the area around the visitor center for signs of breeding birds. This area is a hotspot for breeding activity, and had a good number of birds exhibiting breeding behavior. Two Northern Mockingbirds that Cindy thought might be a pair were, sadly, not within safe dates, so we could not record them as probable breeders.

The DE Breeding Bird Atlas (DE BBA) only allows probable codes within safe dates, which is a big difference between it and the PA Breeding Bird Atlas (PA BBA). However, the DE BBA also uses a code “E” for “encountered,” allowing atlasers to record observations of potential breeding species outside safe dates, even if they show no signs of breeding behavior. The code “E” will be used to further refine safe dates within the state of Delaware, which currently are based on previous safe dates used when Delaware and Maryland were censused at the same time. So we got to code the mockingbird as “E” since they breed in the state, but weren’t in safe dates. The House Sparrows battling for territory were in safe dates, so we got to record them as probable breeders with a code “T” for territorial behavior. Tree Swallows had returned, and already were staked out on nest boxes, most boxes had a bird on top of the roof and one within, which allowed us to confirm the swallows as on nest (code ON), a confirming breeding behavior, which can be recorded outside of safe dates as well as within them. Other species we encountered in the area included Turkey Vulture, Northern Flicker, Carolina Wren, good numbers of lingering juvenile White-crowned Sparrows, Song Sparrows, a calling Eastern Towhee, calling Ring-necked Pheasants and a flyby third winter Bald Eagle, which was a real crowd pleaser. Already, some participants had tallied lifebirds in the forms of Song Sparrow and White-crowned Sparrows. The air was filled with the sound of calling Tundra Swans, and we were able to see some of them on the marsh behind the visitor center. To our delight, we would hear calling Tundra Swans throughout the day and all over the refuge.

I let everyone know my plan for our next area was to drive to Finis Pool and look for breeders and some of the more shy refuge species before heading back to the larger pools. As we headed out, a Savannah Sparrow was just at the side of the dirt road. I was driving at a decent speed for the refuge, but I soon found I was losing my participants. Everyone was so taken with the refuge, that they were crawling along, and I realized we might never actually get to Finis (at least as a group). We really needed to stop on the way so people could get some birding under their belts, so I scrapped my plans and we headed out to the Raymond Pool observation tower. There we enjoyed hundreds of staging Northern Pintails and Northern Shovelers and Green-winged Teal. Mallards and Canada Geese were present as well. A female Cooper’s Hawk cruised from the far shore and shot past the tower while we were there, though few of us really saw her well.

We moved a little down the road and explored the Boardwalk Trail area, where I’d hoped (as usual) that a rail might poke its head out or walk under the little bridge. As usual, the rails, if any were about, were too secretive. We tried to confirm breeding European Starlings seen off the trail. While the starlings did seem to prefer the tree with many natural cavities, no starling actually entered any of the cavities while we were there. We walked out to a little pool of open water, where we found Greater Yellowlegs, but failed to locate any Common Yellowthroats, even though I’d seen one there a month ago. Northern Harriers patrolled the marshes, and a distant adult Bald Eagle perched opposite Raymond Pool. Leaving the Boardwalk Trail, I think everyone felt good about the birding so far, and we all resolved to cut to the chase and get out to Finis.

Now it was my turn to stall. As we came around the corner at Shearness, I couldn’t bring myself to drive past the massive shorebird flock that was on the mudflats. We stopped and put up our scopes. The flock was made up of at least one thousand Dunlin, and Cindy Ahern picked up on 2 Black-bellied Plovers on the left edge of the flock. We lingered here, hoping for something more, but soon got back on track. The road to Finis had a few Dark-eyed Juncos, and Finis was the only location where we found juncos on the refuge. At Finis Pool, we scanned around, locating some Green-winged Teal, Blue-winged Teal, American Wigeons and Wood Ducks. The frog diversity here was quite good, we heard Pickerel Frog, Spring Peeper, Southern Leopard Frog and New Jersey Chorus Frog. Eastern Painted Turtles were basking throughout much of Finis as well.

We explored the area around the Allee House next, where massive flocks of Snow Geese were too wary to allow scope views. Nonetheless the spectacle of all those shimmering white geese against the clear blue sky was a reward in itself. Two American Pipits flew over us as we watched the Snow Geese. Another American Pipit called as we headed back towards Bear Swamp; unfortunately, none of these pipits lingered in the area. A pair of Eastern Bluebirds occupied a nest box on the side of the road as we headed out of the Allee area, which allowed us to confirm another species for the BBA.

At this point, we broke for lunch. During our exodus from the refuge, some of us enjoyed seeing a Red Fox trotting along the dike road. Others found the only Pied-billed Grebe of the trip. Most of us returned to the picnic tables to enjoy our lunch. After fortifying ourselves with Wendy’s or Wawa, we headed back to the impoundments. Raymond Pool presented us with two white Snow Geese, and a third darker goose that initially seemed to be a washed out first year Blue Phase Snow Goose. However, when the bird raised its head a dusky chinstrap marking was apparent. With closer examination, the coloration of the goose was intermediated between blue goose and Canada Goose, and the shape and pattern of the bill was consistent with Canada Goose as well. The goose was the same size as its attendant Snow Geese, and had a wing pattern consistent with Snow Goose. This goose was definitely a hybrid Canada X Snow Goose, the first I’d ever seen. The darker neck indicated that the bird was likely a first year goose, since adult Canada X Snow Geese hybrids typically show an all white head and white first half of the neck. We all had great looks at this unusual bird.

Moving to Shearness Pool, we enjoyed seeing a distant Horned Grebe past the tidal flats. Three Great Egrets and a second winter Bald Eagle were on the mudflats. A Boat-tailed Grackle also roamed the mudflats, calling constantly. In Shearness Pool itself, we enjoyed watching hundreds of Tundra Swans and some Snow Geese. We climbed Shearness Observation Tower to get a better look at the Snow Geese, but failed to find any Ross’s Geese in the flock.

At Bear Swamp, John and Peggy found 4 Ring-necked Ducks, which we saw from the observation tower area of Bear Swamp. A Hairy Woodpecker called from the Bear Swamp trail, which I think was the first one I’ve encountered at the refuge during the BBA. A single Black-crowned Night-heron was on the island where the night-herons roost. Of course, the highlight of the Bear Swamp leg of the trip, and possibly the trip in general, were the 17+ Wilson’s Snipes on the mudflat at Bear Swamp. I found the first one, and soon we were seeing them seemingly everywhere: walking, flying or just standing on the mud. At one point the birds decided to fly from the mudflat to a little island of mud. Jack Beltz counted as they flew away, and this count combined with a few more on the mudflat came to 17 birds, though we all believed there were probably additional snipe in the area. Everyone had a great time watching these snipe, and I noticed an interesting behavior. The snipe tended to land with their heads raised and necks stretched, making them look a little like a yellowlegs when they land. This posture also exposed some lighter feathers in the chin and neck area. After a brief moment of standing seemingly fully exposed, the snipe would then fold into typical snipe posture hiding the more visible feathers on the chin and neck and essentially blending into the background. When you see them erect, you look for a certain shaped bird with light color on the front of the neck. Then, when they collapse into being snipe-like, they are even harder to locate due to the combination of their magnificent camouflage and the fact that you are looking for a bird of a certain pattern and posture that is at odds with how the snipe looks when it is in its typical posture. Essentially, this behavior allows the bird to disappear almost before your eyes. I would not be surprised if this behavior evolved to help snipe disappear from predators that might otherwise track them in flight and located them after landing.

Presently, the group began to disband, and I provided directions for those seeking avocets and suggested those going north could do worse than explore the Middletown Auto Mall where Lapland Longspurs had been seen of late. After everyone else left, I walked out to Parson’s Point, where I happened upon some very close Tundra Swans, and got to enjoy their calling up close. I found an Eastern Phoebe at Bear Swamp. A Fox Sparrow was a big surprise at Finis Pool. I ran a circuit around the pools again, and wound up at the visitor center around dusk. There, I listened for owls and woodcocks. No owls called, but 3-4 American Woodcocks put on some nice courtship flights, and I even got to see one skim across the fields and land near the road, allowing a close approach. Watching those display flights was a great way to end the day.