A walk back to the Slateford Historical Farm produced a 'fly-by' Common Loon and Broad-winged Hawk, plus Hairy and Pileated Woodpecker, White-throated Sparrows, Eastern Towhee, and Blue-winged and Magnolia Warbler.
We walked all the way from the farm down to the Arrow Island Overlook area, adding a Wild Turkey, Common Raven, Gray Catbirds, Veery, American Goldfinch, and Worm-eating Warbler.
On the way back from the Arrow Island area, I just happened to notice a bird pop up a few feet from the ground and perch partly hidden behind a branch. I pointed it out to Adam and our original thought was that it might be a female Common Yellowthroat. Luckily, it flew up to a bush next to the trail and perched in the open with a Ruby-crowned Kinglet. That's when we both realized it was an Orange-crowned Warbler! Unfortunately, I was unable to get a photo of it before it disappeared back into the brush. It had a thin dark eyeline on its pale gray head that slightly contrasted with the drab green back, had no wingbars, and had noticeable yellow undertail coverts, which made it a bird of the 'celata' subspecies. It was a nice surprise to find one in Spring.
In the area around the parking lot at the east end of the drive, we spotted Northern House Wren, Wood Thrush, Chipping Sparrow, Chestnut-sided and Palm Warbler, many more Yellow-rumped Warblers, Scarlet Tanager, Rose-breasted Grosbeak, and Indigo Bunting.
From there, we walked back to the farm and up the road back to our cars, adding 6 'fly-by' Double-crested Cormorants, an Eastern Phoebe, Yellow-throated Vireo among more warblers, an Eastern Bluebird, and Field and Swamp Sparrow.
My checklist contained a total of 58 species, 15 of them warblers! It can be seen here.
On the way back home, I stopped at the Tatamy Exit retention pond, which held a Spotted and a Least Sandpiper.
