This week featured moderate to heavy flights across the southern US, from the Pacific to the Atlantic, and the central US, from Texas to the Canadian border, and these flights included Western Sandpiper, Wilson’s Phalarope, Bonaparte’s Gull, House Wren, Gray Catbird, Magnolia Warbler, Black-throated Blue Warbler, Lincoln’s Sparrow, Lazuli Bunting, Western Tanager, and Summer Tanager.
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Light to moderate movements in the Midwest and portions of the southern Appalachians and mid Atlantic were the only so-called highlights of the beginning of the period last weekend, before a large low pressure center moving across the region shut down most movements. Northern New England did see a nice pulse of birds on Sunday night, as the exception to this larger rule. The remainder of the week featured generally unfavorable conditions for migrants to fly, with locally light and isolated moderate movements punctuating an otherwise quiet (literally) nocturnal migration scene.
Moderate to heavy flights occurred on most nights of this period, with many migrants moving into and through the region. Particularly extensive were the flights of Saturday, Wednesday, and Thursday, when many radars in the region were alive with bird migration; also note that some of these radars were detecting some substantial rain as well. Reports of some fallouts and concentrations during the period continued, given the precipitation early in the weekend, in particular from Alabama and Texas.
The scattered light to moderate movements from Friday and Saturday nights stood in stark contrast to the blanks, so to speak, of Sunday night following the passage of a cold front. As high pressure built into the region, and much cooler temperatures prevailed with unfavorable winds, migration was hard to identify on radar to say the least. But Tuesday night’s moderate flights in the southern Plains previewed the more extensive moderate and even locally heavy flights that followed on Wednesday and Thursday nights.
This week’s light to moderate movements in California and the Desert Southwest were some of the most consistent of the spring season, with birds moving extensively in these areas on almost every night of the period. Additionally, light movements were also apparent farther north along the Pacific Coast and in the Great Basin early in the period, as well as along the eastern front of the Rockies later in the period. Of all the region’s movements this week, California arguably experienced the largest and most consistent.