Forecast and Analysis

Regional Migration Analysis: 14-21 August 2015

Andrew Farnsworth The Cornell Lab Aug 21, 2015

Screenshot 2015-08-21 09.08.58

Continental Summary

Scattered light to moderate movements featuring American Wigeon, Sanderling, Yellow Warbler, Wilson’s Warbler, and Yellow-headed Blackbird highlighted the week in the West, while Black-bellied Plover, Wilson’s Phalarope, Common Nighthawk, Least Flycatcher, Chestnut-sided Warbler, Yellow Warbler, and Wilson’s Warbler composed generally light early period and increasing moderate and even isolated heavy later period movements in the East.

Curious what birds will move next? Check out our migration forecast.

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

Screenshot 2015-08-21 09.07.54Upper Midwest and Northeast

Several days of light movements kicked off the forecast period across the region, with summer like conditions in full effect and muting most movements with unfavorable conditions. But a frontal boundary that began its incursion into the region on Sunday night brought locally moderate to heavy flights in the western Great Lakes. The intensity of these flights continued in the vicinity of the Mississippi River through the end of the period, as the slowing moving system allowed birds to the west of the frontal boundary to take advantage of marginal and favorable flying conditions. Note that much of the remainder of the region was quiet in advance of this frontal passage, but with its passage on Thursday night more moderate flights followed.

Top Movers

Increasing

Species Increase from Last Week % of Checklists Reporting
Common Nighthawk 121% 2.4
Black Tern 105% 2.6
Canada Warbler 52% 2.6
Blue-winged Teal 35% 3.6
Tennessee Warbler 96% 1.3
Western Sandpiper 91% 1
Chestnut-sided Warbler 25% 3.4
Semipalmated Sandpiper 14% 13.8
Black-and-white Warbler 17% 6.6
Blackburnian Warbler 37% 1.7
Northern Shoveler 68% 0.9
Cooper's Hawk 18% 4.8
Olive-sided Flycatcher 56% 0.9
Baltimore Oriole 11% 14.2
Least Flycatcher 26% 2.1
Least Sandpiper 10% 16.2
Lesser Yellowlegs 11% 11.3
Laughing Gull 10% 11.3
Mallard 6% 28.6
Greater Yellowlegs 10% 9.9
Wilson's Warbler 169% 0.3
Northern Waterthrush 17% 2.7
Baird's Sandpiper 34% 1.4
Blue-winged Warbler 21% 1.8

Decreasing

Species Decrease from Last Week % of Checklists Reporting
Indigo Bunting -27% 11.5
Dickcissel -48% 0.6
Yellow Warbler -25% 6.6
Red-winged Blackbird -20% 19.6
Hermit Thrush -41% 0.8
Purple Martin -16% 6
Swamp Sparrow -25% 2.4
Eastern Meadowlark -27% 1.3
Willow Flycatcher -24% 2.1
Field Sparrow -16% 5.8
Common Yellowthroat -15% 13.4
Grasshopper Sparrow -43% 0.4
Acadian Flycatcher -30% 1
Marsh Wren -21% 1.9
House Wren -12% 10.9
Northern Rough-winged Swallow -14% 4.4
Orchard Oriole -26% 1.1
Chipping Sparrow -10% 14.9

Screenshot 2015-08-21 09.04.48

Gulf Coast and Southeast

Light movements dominated the migration scene across the Southeast during this period. Last weekend’s light to locally moderate flights in Texas probably consisted of as many local bat and insect flights as bird movements. Other parts of the region showed sparse migration signals as generally warm and unfavorable conditions for migration prevailed. The end of the period, particularly Wednesday and Thursday nights, saw more extensive light to locally moderate flights first west and then farther east of the Mississippi River valley; presumably more birds, rather than insects and bats, participated in these flights than those from earlier in the period, given a frontal boundary’s edges in the great river’s vicinity on Wednesday night.

Top Movers

Increasing

Species Increase from Last Week % of Checklists Reporting
Northern Waterthrush 55% 1.4
Wilson's Phalarope 138% 1.7
Black-bellied Plover 36% 4.7
Prairie Warbler 21% 5.2
Chestnut-sided Warbler 57% 0.7
Western Sandpiper 25% 3.3
Marbled Godwit 31% 1.7
American Redstart 19% 3.5
Blue-winged Teal 24% 1.6
Blue-winged Warbler 56% 0.4
Blue-gray Gnatcatcher 10% 20
Northern Parula 13% 6.5
Long-billed Dowitcher 21% 1.5
Short-billed Dowitcher 15% 2.8

Decreasing

Species Decrease from Last Week % of Checklists Reporting
Swallow-tailed Kite -40% 0.9
Common Yellowthroat -27% 3
Wood Thrush -67% 0.2
Purple Martin -22% 4.4
Least Tern -19% 4
Indigo Bunting -16% 8.1
Western Kingbird -21% 2.1
American Robin -13% 9.7
Blue-headed Vireo -39% 0.4
Red-winged Blackbird -11% 13.4
Brown-headed Cowbird -13% 3.9

Screenshot 2015-08-21 09.10.59

Great Plains

Light to moderate movements punctuated the northern Plains’ states weekend, with movements persisting into the early part of the work week. By midweek, the central Plains’ states participated in the action, with moderate and even locally heavy flights on Tuesday and Wednesday nights. These movements coincided with the frontal boundary passing east across the region and the more favorable northerly and slightly cooler flow following in its wake.

Top Movers

Increasing

Species Increase from Last Week % of Checklists Reporting
Wilson's Warbler 829% 3.3
Blackburnian Warbler 1000+% 1.8
Least Flycatcher 157% 8.5
Yellow Warbler 153% 19.6
Franklin's Gull 38% 13
Black-and-white Warbler 116% 2.7
American Golden-Plover 665% 1.4
Ring-billed Gull 24% 18.6
Black-bellied Plover 65% 2.7
Spotted Sandpiper 24% 16.5
Baltimore Oriole 22% 14.8
American Redstart 70% 2.3
Black-necked Stilt 69% 2.6
Least Sandpiper 18% 11.8
Merlin 71% 1.9

Decreasing

Species Decrease from Last Week % of Checklists Reporting
Western Kingbird -33% 7.9
Willow Flycatcher -57% 0.5
Sora -39% 1.7
Western Meadowlark -29% 7.2
Grasshopper Sparrow -35% 2.6
House Wren -16% 9.7
Bobolink -57% 0.3
Lark Sparrow -17% 6.5
Spotted Towhee -52% 0.6
Common Yellowthroat -21% 6.1
Brown-headed Cowbird -22% 6.3
Orchard Oriole -22% 5.2
Red-winged Blackbird -12% 20.9

Screenshot 2015-08-21 09.12.50

West

Despite a forecast that called for pulses to begin and end the forecast period, the West saw more consistent light to moderate flights for the entirety of the period. California and the Desert Southwest began the weekend with such movements, but the intermountain west quickly joined the migration game with scattered light to moderate movements on Saturday and Sunday nights. These movements continued in similar intensities and extents for the remainder of the period. Note that, similar to the Southeast region’s movements that included insects and bats, so to are many movements in places like New Mexico and portions of the eastern front of the Rockies composed of birds, bats, and insects.

Top Movers

Increasing

Species Increase from Last Week % of Checklists Reporting
Wilson's Warbler 44% 13.7
Townsend's Warbler 112% 2.8
Northern Shoveler 30% 5.1
Green-winged Teal 31% 4.7
Yellow Warbler 21% 15.9
MacGillivray's Warbler 30% 4.6
Brewer's Sparrow 59% 2.5
Orange-crowned Warbler 21% 8.3
Willow Flycatcher 31% 4.4
Yellow-headed Blackbird 45% 3.9
Black Phoebe 20% 20.2
Short-billed Dowitcher 32% 2.5
Sanderling 33% 2.2
Least Sandpiper 13% 14.2
Savannah Sparrow 15% 7
Semipalmated Plover 19% 6.4
Solitary Sandpiper 29% 2.3
American Wigeon 38% 1.4
Baird's Sandpiper 24% 2.6
Nashville Warbler 23% 3
Clay-colored Sparrow 110% 0.5

Decreasing

Species Decrease from Last Week % of Checklists Reporting
White-throated Swift -23% 1.3
Olive-sided Flycatcher -27% 1.4
Blue Grosbeak -15% 4.7
Cassin's Finch -24% 1.3
Hermit Thrush -35% 0.7

–––––––––––––––––––––––––––––––––––

Farnsworth and Van Doren

POWERED BY