Wednesday, May 11, 2011

Sterling Forest

May 11th is the earliest I have ever been to Sterling Forest - when I first went there I favored early June although more recently I've been more likely to go there at the end of May. So this was somewhat of an experiment. The novel experience was the presence of some migrants in what otherwise would be considered classic northern deciduous breeding habitat (Yellow-rumped Warbler, Nashville Warbler, Blackpoll Warbler, White-crowned Sparrow). The female Black-throated Blue was probably a migrant too. In the end I racked up quite a decent total of warblers, although some species were heard-only, and unquestionably my best for this site.

The main targets at Sterling Forest are Golden-winged Warbler and Cerulean Warbler. I heard two Ceruleans and saw/heard about six Golden-winged. All males. I didn't see any sign of females but perhaps since this is mid migration they are en route. Unfortunately I also saw four Blue-winged, a personal high total, which doesn't bode well for this little enclave of Golden-winged. In fact one Blue-winged was singing in the same tree as a Golden-winged without territorial exclusion, which illustrates how this sort of hybridization can so easily come about.

My usual initial spot for Golden-winged has been trashed by the power line company, which likes to destroy habitat of endangered species by chemical and mechanical means. Looks like that will take a few years to bounce back, assuming it ever does. I've also seen these jackasses prune trees in breeding season, including destroying an American Redstart nest in the process and right next to a Golden-winged nesting site. Of course the power line cut itself is providing niche habitat for Golden-winged, especially after habitat encroachment or succession of its more usual sites. Golden-winged is essentially extirpated in NJ, at least from any publicized spots - the last site that I knew of near Layton has gone too far in succession. Although Cerulean is relatively rare, Golden-winged is much rarer as a regional breeding species.

However at least the most prominent spot for Golden-winged at Ironwood Road is mostly intact. Here Golden-winged, Prairie, Chestnut-sided, Yellow and Common Yellowthroat were on territory. I felt that the numbers of Prairie and Chestnut-sided were on the low side, but this may reflect ongoing migration especially of the latter species.

Here's the list, with 17 warbler species:
Green Heron
Red-tailed Hawk
Chimney Swift
Ruby-throated Hummingbird
Great Crested Flycatcher
Eastern Kingbird
Yellow-throated Vireo
Red-eyed Vireo
Tree Swallow
Barn Swallow
Black-capped Chickadee
Wood Thrush
Gray Catbird
Blue-winged Warbler
Golden-winged Warbler
Nashville Warbler
Northern Parula
Yellow Warbler
Chestnut-sided Warbler
Black-throated Blue Warbler
Yellow-rumped Warbler
Prairie Warbler
Blackpoll Warbler
Cerulean Warbler
Black-and-white Warbler
American Redstart
Louisiana Waterthrush
Common Yellowthroat
Hooded Warbler
Scarlet Tanager
Eastern Towhee
Field Sparrow
White-crowned Sparrow
Rose-breasted Grosbeak
Indigo Bunting
Brown-headed Cowbird
Baltimore Oriole
American Goldfinch

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