Rarely found outside stands of its namesake tree, it is one of the few wood-warblers whose breeding and wintering ranges lie almost entirely within the U.S. and Canada. Although resident subspecies occur on Hispaniola and in the Bahamas, Pine Warblers nesting in forests of southeastern Canada and the Northeast join those from southeastern states in winter, where they can be surprisingly abundant, with as many as 50-100 birds joining mixed-species foraging flocks.
The Pine Warbler is far more often heard than seen in Vermont, where it rarely ventures below the canopy of mature white and red pines. Consequently, it is one of the least well-studied North American breeding warblers. Nests are typically located near the ends of horizontal limbs, often more than 50 feet above ground, and eggs may be laid as early as the first week of May. Although primarily an insect eater, this species is the only wood-warbler known to regularly consume seeds, especially in fall and winter. Pine Warblers occasionally delight birders by visiting feeders during winter, taking both seeds and suet. Their digestive system is able to compensate for this seasonal dietary shift by modulating enzyme production.
For Vermont birders, waterfowl have ceased to dominate the highlight reels, as the recent warm southerly air flow has brought a diverse push of early migrants. Vermont’s only pair of Sandhill Cranes returned for a fourth year to Bristol Pond, where observers are urged to use caution and respect in viewing them. Among wading birds reported during the past week were a Great Egret in Shelburne, three Black-crowned Night-Herons at Delta Park in Winooski, and a Virginia Rail at the West Rutland Marsh. Shorebirds included four reports of Greater Yellowlegs, one Lesser Yellowlegs at Brattleboro Retreat Meadows, a Spotted Sandpiper in Ludlow, and an Upland Sandpiper in West Brattleboro. Two Caspian Terns were observed along Lewis Creek in Addison and a single bird on Shelburne Bay.
Among landbirds, Broad-winged Hawks returned to the state en masse, while a Merlin was sighted in Proctor. Well ahead of its normal spring migration schedule was a Common Nighthawk at Brattleboro Retreat Meadows on April 19th. Also early was an Eastern Kingbird at the North Branch Nature Center in Montpelier on the 14th. An intriguing report of a Red-headed Woodpecker from Castleton on the 16th lends hope that this declining species, which has all but disappeared from Vermont, may still breed within the state. Purple Martins, Northern Rough-winged Swallows, and Bank Swallows all returned within the past week, while new songbird arrivals included Blue-headed Vireos, Brown Thrashers, Palm Warblers, Louisiana Waterthrush, Common Yellowthroat, Eastern Towhees, and an early Indigo Bunting.
Avian hold-outs from the still-retreating winter season included single Northern Shrikes in Essex Junction and Windsor, BoBunting in Berlin, and numerous Common Redpoll flocks in the northern half of Vermont.
You can explore all the birds reported last week in Vermont and add your own sightings at Vermont eBird.