There are 9 or 10 at two locations. The biggest colony is at Rodale (below), where they were last year. There may be others in the county. There's plenty of similar habitat.
Rodale Experimental Farm, Maxatawny Twp., Berks, Pennsylvania, US Jul 8, 2017 7:00 AM - 9:20 AM Protocol: Traveling 0.4 mile(s) Comments: Overcast to partly cloudy, light westerly wind, 67-78F. 34 species
Turkey Vulture 1 Cooper's Hawk 1 Large Barn Swallow escort. Killdeer 9 Rock Pigeon (Feral Pigeon) 5 Mourning Dove 60 Large postbreeding flock. Red-bellied Woodpecker 1 Eastern Kingbird 3 Blue Jay 1 Horned Lark 4 Purple Martin 3 Tree Swallow 105 Large postbreeding flock on wires and hunting insects over wetland. Barn Swallow 55 Many adults with fledged young, some still being fed. Carolina Wren 2 American Robin 18 Gray Catbird 2 Northern Mockingbird 1 European Starling 150 Common Yellowthroat 2 Grasshopper Sparrow 3 Chipping Sparrow 2 Field Sparrow 5 Savannah Sparrow 4 Song Sparrow 8 Northern Cardinal 2 Indigo Bunting 2 Dickcissel 7 A female perched on a fencepost with dried grass in her bill. A male repeatedly hovered over her soliciting copulation, which took place when female consented. Following copulation, female flew down into the pasture with the nesting material and the male flew to a nearby weed stalk, where it commenced singing in response to the several other males singing nearby. About 0.1 mile away in an alfalfa field extensively invaded by chicory, a male flew in close company with a female from one stalk of chicory to another. This pair finally disappeared into the adjacent cornfield. Two other males sang unobserved from concealed perches in the pastures. A third male sang from utility wires above a field of alfalfa that was regrowing after earlier cutting. It appears that rotational grazing of pasture plots by dairy cows is ensuring that some tall grass is always available for grassland bird species. Note that Savannah and Grasshopper Sparrows, Bobolinks and Red-winged Blackbirds have all been confirmed nesting here this season. Bobolink 4 Red-winged Blackbird 15 Common Grackle 8 Brown-headed Cowbird 2 Orchard Oriole 1 House Finch 20 American Goldfinch 10 House Sparrow 5