Forecast and Analysis

Regional Migration Analysis: 4-11 September 2015

Andrew Farnsworth The Cornell Lab Sep 11, 2015

Screenshot 2015-09-11 13.42.31

Continental Summary

A big week for migration saw Ruby-crowned Kinglet, Orange-crowned Warbler, Yellow-rumped Warbler, Green-tailed Towhee, White-crowned Sparrow, and Golden-crowned Sparrow migrate in light to moderate flights across the West and Blue-winged Teal, Bald Eagle, Swainson’s Thrush, Ruby-crowned Kinglet, Nashville Warbler, Orange-crowned Warbler, Yellow-rumped Warbler, Magnolia Warbler, Palm Warbler, Blackpoll Warbler, Bay-breasted Warbler, and Baltimore Oriole moving in moderate to heavy flights in the East.

Need a review of our definitions for regions, species on the move, and migration amounts? Please visit this link.

Quick Links to Regions

Upper Midwest and NortheastBirdCast Upper Midwest and Northeast Region Gulf Coast and SoutheastBirdCast Upper Southeast Region
Great Plainsbirdcast_plains West
BirdCast West Region

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Upper Midwest and Northeast

Light to moderate flights were scattered across the region last weekend, but this relatively small push stood in stark contrast of the movements that would come. A cold front moving through the Great Lakes brought heavy and very heavy flights on Sunday night to the Upper Midwest. The intensity of these flights continued in this part of the region through Tuesday night, as the frontal boundary slowly drifted east. By Wednesday night moderate to heavy flights occurred across much of the region west of the Appalachians, with the coast still experiencing rather warm summer like conditions unfavorable for flights. With the front’s eventual passage off the coast on Thursday night, moderate to heavy flights finally appeared east of the Appalachians while continuing their push in the Upper Midwest. Note that few areas of the coast experienced large flights, away from northern New England early Thursday evening.

Top Movers

Increasing

Species Increase from Last Week % of Checklists Reporting
Palm Warbler 311% 3.6
Blackpoll Warbler 162% 6.6
Swainson's Thrush 105% 9.6
Bay-breasted Warbler 87% 5.1
Gray-cheeked Thrush 330% 1.7
Black-throated Green Warbler 54% 9.2
Nashville Warbler 51% 7.6
Wilson's Warbler 45% 5
Philadelphia Vireo 56% 3.2
Pied-billed Grebe 59% 5.2
American Golden-Plover 51% 3.1
Tennessee Warbler 33% 9.6
Magnolia Warbler 22% 14.1
Northern Parula 31% 4.4
Orange-crowned Warbler 604% 0.4
Northern Flicker 12% 28.7
Yellow-throated Vireo 24% 5.8
Dark-eyed Junco 52% 1.8
American Wigeon 130% 0.7
Rose-breasted Grosbeak 17% 8.2
Merlin 27% 3.5
Cape May Warbler 29% 3
Yellow-rumped Warbler 22% 3.2
Blue-headed Vireo 28% 2.2
Lincoln's Sparrow 83% 0.6

Decreasing

Species Decrease from Last Week % of Checklists Reporting
Baltimore Oriole -58% 3.1
Eastern Kingbird -54% 2.9
Barn Swallow -42% 7.9
Common Nighthawk -46% 3.2
Short-billed Dowitcher -45% 1.5
Purple Martin -76% 0.4
Ruddy Turnstone -50% 0.7
Bank Swallow -47% 0.9
Blue-gray Gnatcatcher -27% 6.8
Semipalmated Sandpiper -28% 5.8
Great Crested Flycatcher -21% 5.1
Western Sandpiper -42% 0.7
Glossy Ibis -55% 0.3
Wilson's Storm-Petrel -95% 0
Eastern Wood-Pewee -14% 20.4
Least Sandpiper -18% 9.5
Canada Warbler -24% 2.3
Semipalmated Plover -16% 7
Common Grackle -16% 13.6
Ruby-throated Hummingbird -12% 25.5
White-rumped Sandpiper -35% 0.8

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Gulf Coast and Southeast

Primarily unfavorable migration conditions prevailed for the first half of the week. Light to moderate flights were peppered across the region, with little deviation in intensity and relatively limited geographic extent. Wednesday and Thursday nights saw these unfavorable conditions finally break in many areas, with moderate and locally heavy flights following suit. Larger flights were particularly apparent in the southern Appalachians to end the period.

Top Movers

Increasing

Species Increase from Last Week % of Checklists Reporting
Baltimore Oriole 58% 6.9
Blue-winged Teal 82% 8.2
Nashville Warbler 607% 1.8
Magnolia Warbler 76% 3.5
Scarlet Tanager 45% 3.2
Tennessee Warbler 48% 2.5
Veery 53% 1.8
Swainson's Thrush 97% 1
Rose-breasted Grosbeak 99% 1
Golden-winged Warbler 94% 0.9
Ovenbird 29% 4.4
Northern Shoveler 48% 2.3
Wilson's Snipe 67% 1.2
Common Yellowthroat 23% 7.1
Brown Thrasher 14% 12.2
Pine Warbler 16% 9.9
Cape May Warbler 40% 0.9
Chestnut-sided Warbler 21% 5.2

Decreasing

Species Decrease from Last Week % of Checklists Reporting
White-crowned Pigeon -82% 0
Least Bittern -45% 0.6
Chuck-will's-widow -55% 0.3
Mississippi Kite -31% 2.1
Louisiana Waterthrush -48% 0.3
Least Tern -31% 1.5
Northern Waterthrush -30% 2.6
Black Tern -23% 2.6
Eastern Kingbird -15% 6.5
Eastern Meadowlark -27% 1.2
Great Crested Flycatcher -11% 9
Barn Swallow -6% 18.3

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Great Plains

Quiet weekend beginnings got loud by Sunday night, when moderate to heavy flights prevailed across the region behind a passing cold front. Similarly intense movements occurred in the middle and end of the week, in local pulses, as birds took advantage of several bursts of favorable conditions for flight. Particularly hot this period were areas of the central and southern Plains, which generally experienced larger flights during the pulses of movement than parts further north.

Top Movers

Increasing

Species Increase from Last Week % of Checklists Reporting
Orange-crowned Warbler 282% 9
Ruby-crowned Kinglet 515% 4.5
Yellow-rumped Warbler 110% 6.8
Ovenbird 212% 6.6
Wilson's Warbler 92% 13.2
White-throated Sparrow 466% 1.7
Lincoln's Sparrow 121% 3.7
Swainson's Thrush 60% 9.7
Nashville Warbler 64% 7.4
Blue-headed Vireo 53% 3.6
Black-throated Green Warbler 75% 1.4

Decreasing

Species Decrease from Last Week % of Checklists Reporting
Eastern Kingbird -40% 11
Cliff Swallow -44% 4
Western Kingbird -56% 1.6
Purple Martin -76% 0.5
Barn Swallow -21% 28.6
Baltimore Oriole -23% 14.4
Stilt Sandpiper -29% 4.2
Bank Swallow -35% 3
Dickcissel -37% 3.2
Philadelphia Vireo -42% 1.2
Least Sandpiper -20% 5.8

Screenshot 2015-09-11 13.41.58

West

This period saw consistent light to moderate flights for much of the region. Almost all areas of the West participated in the movements: moderate flights early and mid period in the Pacific Northwest; moderate flights in the Rockies and portions of the Desert Southwest mid and late period; and moderate flights from the Great Basin through the eastern front of the Rockies at the end of the period.

Top Movers

Increasing

Species Increase from Last Week % of Checklists Reporting
Ruby-crowned Kinglet 89% 5.3
White-crowned Sparrow 49% 15.3
Golden-crowned Sparrow 225% 1.6
Lincoln's Sparrow 44% 5.1
Green-tailed Towhee 63% 4
American Pipit 61% 2.5
Fox Sparrow 74% 1.9
Yellow-rumped Warbler 26% 13.9
Golden-crowned Kinglet 34% 4.2
Swainson's Thrush 27% 5.1
Orange-crowned Warbler 18% 18.1
American Wigeon 24% 4.2
Savannah Sparrow 18% 10.6
Clay-colored Sparrow 45% 1.5
Horned Grebe 38% 1.2
Common Yellowthroat 14% 15.5
Eared Grebe 29% 3.9
White-throated Sparrow 1886% 0.2
Say's Phoebe 17% 7.2

Decreasing

Species Decrease from Last Week % of Checklists Reporting
Wilson's Phalarope -65% 0.7
Violet-green Swallow -53% 4.6
Solitary Sandpiper -42% 0.8
Semipalmated Sandpiper -55% 0.4
Broad-tailed Hummingbird -28% 3.6
Western Kingbird -30% 3
Franklin's Gull -40% 0.7
American Avocet -26% 3.8
Bank Swallow -38% 0.9
Tree Swallow -28% 2.1
Eastern Kingbird -60% 0.3
Virginia's Warbler -39% 1
Baird's Sandpiper -26% 1.7
Cliff Swallow -28% 2.2
Short-billed Dowitcher -30% 1
Vaux's Swift -42% 2.9
Brown-headed Cowbird -23% 2.4
Least Sandpiper -15% 8.9
Western Sandpiper -16% 7.2
Bullock's Oriole -27% 1.1
Long-billed Dowitcher -19% 2.8
Cordilleran Flycatcher -40% 0.3

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Farnsworth and Van Doren

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