When, where, and how far will birds migrate? Our migration forecasts will answer these questions for the first time.
With peaks of spring movements in the rear view for most species, this week will see scattered light flights across much of the West, with moderate flights along the eastern front of the Rockies, that will feature Black Tern, Cordilleran Flycatcher, Willow Flycatcher, MacGillivray's Warbler, and Blue Grosbeak, and moderate to heavy midweek flights where and when precipitation does not fall in the East, featuring Black-bellied Plover, Black Tern, Olive-sided Flycatcher, Alder Flycatcher, Yellow-bellied Flycatcher, and Mourning Warbler.
A reasonable quiet late migration season week in the West featured movements of Black Tern, Olive-sided Flycatcher, Swainson's Thrush, Gray Catbird, Northern Waterthrush, American Redstart, particularly in the Desert Southwest and northern Rockies, while moderate to heavy flights in the East early in the week, featuring White-rumped Sandpiper, Sanderling, Black Skimmer, Eastern Wood-Pewee, Marsh Wren, Saltmarsh Sparrow, and Orchard Oriole, subsided as a more early spring like air mass arrived.
Scattered precipitation across the region this period will add a new dynamic to West, with light to moderate movements featuring Common Nighthawk, Western Wood-Pewee, Eastern Kingbird, Western Tanager, and Lazuli Bunting where precipitation is not falling mostly early in the week in the Southwest and central and southern Rockies, while an early period blast of moderate to heavy movements featuring White-rumped Sandpiper, Common Nighthawk, Willow Flycatcher, Yellow-bellied Flycatcher, Philadelphia Vireo, Tennessee Warbler, and Blackpoll Warbler gets swept aside with the passage of a strong frontal boundary in the middle of the week.
Several widespread pulses of moderate to heavy flights featuring White-rumped Sandpiper, Stilt Sandpiper, Ruddy Turnstone, Common Nighthawk, Eastern Wood-Pewee, Alder Flycatcher, Blackpoll Warbler, and Mourning Warbler punctuated the week across the East, while mid week moderate to locally heavy flights along the eastern Rockies were highlights of the period's assemblage of Black Tern, Least Flycatcher, Dusky Flycatcher, Plumbeous Vireo, Swainson's Thrush, MacGillivray's Warbler, and Blue Grosbeak in the West.
Favorable conditions for light to moderate flights begin and ends the period for the West as Black-bellied Plover, Lesser Yellowlegs, Willow Flycatcher, Swainson's Thrush, Townsend's Warbler, Virginia Warbler, and Blue Grosbeak are on the move, while the moderate to heavy flights that will include White-rumped Sandpiper, Short-billed Dowitcher, Least Flycatcher, Philadelphia Vireo, Blackpoll Warbler, Chestnut-sided Warbler, Wilson's Warbler, Rose-breasted Grosbeak, Savannah Sparrow and White-crowned Sparrow navigate around some serious weather in the first half of the period and quiet markedly with that weather's departure to end the period.
Widespread favorable conditions that bring light to moderate flights including Solitary Sandpiper, Western Wood-Pewee, Dusky-capped Flycatcher, Gray Flycatcher, Warbling Vireo, Orange-crowned Warbler, Yellow-breasted Chat, and Black-headed Grosbeak to the West early in the week become increasingly restricted to the Desert Southwest by the end of the week, while the arriving major pulse of southerly flow and warmer air toward the end of the weekend in the East brings moderate to heavy, and locally very heavy, flights for the rest of the period that will include Broad-winged Hawk, Least Sandpiper, Olive-sided Flycatcher, Veery, Wood Thrush, Wilson's Warbler, Mourning Warbler, Black-throated Blue Warbler, Lincoln's Sparrow, White-throated Sparrow, Rose-breasted Grosbeak.