Regional Migration Analysis: 15-22 September 2017

Savannah Sparrow. Fyn Kynd/Macaulay Library. eBird S39302831.

Continental Summary

Moderate to locally heavy flights occurred in many areas of the West this period and featured Cackling Goose, Greater White-fronted Goose, Ring-necked Duck, Merlin, American Pipit, Fox Sparrow, Golden-crowned Sparrow, and Lincoln’s Sparrow, while moderate to locally very heavy flights occurred in the East, featuring Sharp-shinned Hawk, Gray-cheeked Thrush, Ruby-crowned Kinglet, Yellow-rumped Warbler, Palm Warbler, Savannah Sparrow, Harris’ Sparrow, White-crowned Sparrow and White-throated Sparrow.

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Upper Midwest and Northeast

Moderate and heavy flights were distributed around the region in favorable migration conditions, with most flights east of the Ohio River Valley to kick off the weekend and more flights to the west of this area to end the weekend. Slightly less intense flights continued for the days that followed into the middle of the work week, with many areas experiencing moderate flights. By Wednesday night an interesting pattern appeared, as a frontal boundary sat over the western Great Lakes and the remnants of Hurricane Jose sat off the Atlantic Coast. To the west of the frontal boundary, typical frontal passage conditions were favorable for migration and moderate to locally very heavy flights were aloft; but to the east of the front, sandwiched between it and the circulation of Jose, conditions were also favorable for moderate and locally heavy flights. The storm’s circulation and high pressure over land to the west created a favorable northerly and northeasterly flow for birds to move. As the tropical system maintained its position off the Atlantic on Thursday night, moderate and locally heavy flights continued in the swath of circulation between it and the Ohio River Valley high pressure center.

Top Movers

Increasing

Species Increase from Last Week % of Checklists Reporting
Ruby-crowned Kinglet 530% 4.5
Sharp-shinned Hawk 169% 5.9
Lincoln's Sparrow 287% 3.1
White-throated Sparrow 255% 4.8
Palm Warbler 137% 8.7
Savannah Sparrow 111% 5.2
Yellow-rumped Warbler 97% 5.7
American Pipit 274% 1.5
White-crowned Sparrow 987% 0.9
Blue-headed Vireo 102% 3.7
Orange-crowned Warbler 394% 0.7
Northern Flicker 32% 32.9
Gray-cheeked Thrush 92% 2.2
American Kestrel 45% 6.3
Brown Thrasher 48% 6.8
Swamp Sparrow 68% 3.8
Merlin 51% 4.8
Wilson's Snipe 76% 1.5
Yellow-bellied Sapsucker 49% 2.4
Winter Wren 125% 0.8
Broad-winged Hawk 41% 4.2
American Coot 68% 1.7

Decreasing

Species Decrease from Last Week % of Checklists Reporting
Barn Swallow -100% 0
Blue-gray Gnatcatcher -84% 1.4
Great Crested Flycatcher -93% 0.4
Ruby-throated Hummingbird -57% 11.2
Warbling Vireo -69% 2.6
Tree Swallow -64% 3.8
Eastern Wood-Pewee -49% 10.7
Baltimore Oriole -87% 0.6
Least Flycatcher -75% 1
Least Sandpiper -63% 2.5
Canada Warbler -87% 0.4
Semipalmated Sandpiper -58% 3.1
Common Nighthawk -64% 1.9
Chestnut-sided Warbler -52% 4.2
Blue-winged Warbler -92% 0.1
Red-eyed Vireo -34% 13.1
Eastern Kingbird -81% 0.7
Blackburnian Warbler -65% 1.6
Veery -70% 1
Olive-sided Flycatcher -88% 0.2
Semipalmated Plover -47% 3.8
American Redstart -28% 15.5
Northern Rough-winged Swallow -72% 0.7
Caspian Tern -49% 2.4
Osprey -28% 9.1

Cape May Warbler. Steve Calver/Macaulay Library. eBird S39187405.

Gulf Coast and Southeast

Moderate and locally heavy flights were the norm in many areas of the region during this period. The distribution of these flights was skewed primarily to areas east of the Mississippi for much of the period, as favorable wind conditions in these areas associated with the offshore and slow northward passage of Hurricane Jose facilitated movements. One exception was Wednesday night –  conditions in the western reaches of the region improved with the arrival of a frontal boundary in north and west Texas, while conditions in the remainder of Texas and areas to the west of the Mississippi River were largely marginal or unfavorable and under the influence of high pressure to the northeast. As the frontal boundary passed through the Texas Panhandle, moderate to heavy flights occurred; but between the frontal boundary and the more favorable conditions east of the Mississippi River, flights were light and local at best.

Top Movers

Increasing

Species Increase from Last Week % of Checklists Reporting
Swainson's Thrush 486% 5.4
Magnolia Warbler 162% 8.2
Palm Warbler 653% 4.1
Rose-breasted Grosbeak 664% 3.2
Gray Catbird 78% 12.2
Common Yellowthroat 93% 10.5
Scarlet Tanager 171% 5.1
Northern Flicker 89% 8.6
Brown Thrasher 58% 15.7
Tennessee Warbler 160% 5.1
Merlin 380% 1.8
Cape May Warbler 225% 2.6
Gray-cheeked Thrush 1760% 1.2
Northern Mockingbird 22% 42.7
Eastern Phoebe 35% 16.6
Philadelphia Vireo 542% 1
House Wren 98% 2.6
American Redstart 35% 13.8
Chestnut-sided Warbler 60% 5.3
Black-throated Green Warbler 73% 3.4
Ruby-crowned Kinglet 354% 0.7
Tufted Titmouse 17% 33

Decreasing

Species Decrease from Last Week % of Checklists Reporting
Great Crested Flycatcher -59% 3.3
Eastern Kingbird -57% 2.6
Purple Martin -79% 0.6
Bank Swallow -73% 0.7
Spotted Sandpiper -47% 3.4
Pectoral Sandpiper -58% 1.8
Black Tern -70% 0.9
Barn Swallow -40% 10.7
Least Sandpiper -40% 5.4
Semipalmated Sandpiper -52% 1.9
Blue Grosbeak -48% 2.6
Solitary Sandpiper -64% 0.9
Lesser Yellowlegs -48% 2.5
Cliff Swallow -58% 1.2
Least Tern -85% 0.3
Mississippi Kite -77% 0.4
Green Heron -33% 5.9
Northern Rough-winged Swallow -44% 2.2
Stilt Sandpiper -52% 1.2
Blue-winged Teal -39% 3.4
Semipalmated Plover -38% 3.1
Bullock's Oriole -95% 0
White-winged Dove -19% 10.6

American White Pelican. Kelly Preheim/Macaulay Library. eBird S39118167.

Great Plains

A pulse of moderate to locally very heavy flights graced parts of the region on Saturday night, especially over the central Plains. Several days of relative quiet followed this intense movement, as conditions became generally less favorable for migrants to take flight. Another frontal passage arrived on Tuesday night, but its impacts were again more local than regional; moderate to locally heavy flights occurred in the northern and central Plains. Note that this frontal boundary was actually represented by two fronts, a more easterly and more intense line of storms, and then a more westerly line of precipitation; both spawned movements. With the movements of this system to the east, moderate to locally very heavy flights shifted to the central and southern Plains by Wednesday night. By Thursday most flights associated with this passage had moved out of the region, but a new pulse of moderate to heavy flights was aloft locally in the northern Plains in reasonably favorable migration conditions in the Dakotas.

Top Movers

Increasing

Species Increase from Last Week % of Checklists Reporting
White-crowned Sparrow 664% 6.2
Yellow-rumped Warbler 194% 8.6
Western Meadowlark 97% 14.3
Orange-crowned Warbler 112% 10.2
Ruby-crowned Kinglet 117% 7
Osprey 109% 7.5
Vesper Sparrow 129% 5.5
Savannah Sparrow 136% 4.7
Sharp-shinned Hawk 145% 3.4
Northern Flicker 43% 28.3
Ring-billed Gull 52% 15
Harris's Sparrow 2887% 1.2
Franklin's Gull 50% 15.2
Townsend's Solitaire 693% 1.2
White-throated Sparrow 89% 3.9
American White Pelican 45% 9.6
Rock Wren 218% 1.5
Merlin 89% 3.3
Dark-eyed Junco 207% 1.6
American Coot 44% 8.4
Spotted Towhee 60% 4.4
Red-winged Blackbird 30% 15.1
Wilson's Snipe 71% 2.8
Ruddy Duck 70% 3.3

Decreasing

Species Decrease from Last Week % of Checklists Reporting
Warbling Vireo -92% 1
Great Crested Flycatcher -99% 0.1
Eastern Kingbird -89% 1.1
Least Flycatcher -82% 1.5
Yellow Warbler -77% 2.2
Olive-sided Flycatcher -90% 0.5
Baltimore Oriole -84% 1.3
Blue-gray Gnatcatcher -78% 1.7
Red-eyed Vireo -73% 3.1
Yellow-billed Cuckoo -87% 0.6
American Redstart -75% 1.6
Barn Swallow -45% 14.8
Ovenbird -98% 0
Black-and-white Warbler -79% 0.8
Little Blue Heron -83% 0.5
American Goldfinch -31% 20.4
Tree Swallow -75% 0.9
Ruby-throated Hummingbird -38% 9.1
Eastern Wood-Pewee -45% 5.3
Cedar Waxwing -42% 5.6
Semipalmated Sandpiper -82% 0.5
Red-headed Woodpecker -38% 8.3
Northern Mockingbird -49% 4.2

American Pipit. Mary Rumple/Macaulay Library. eBird S39285120.

West

Moderate to locally heavy flights were scattered across the region for the weekend, particularly over the Central Valley of California and portions of the Rockies. Increasing precipitation in the northern half of the region shut down most movements to begin the work week, while light to moderate flights continued in California and the Desert Southwest. Local moderate to heavy flights took off from the Rockies on Tuesday and Wednesday nights, while movements in California and the Desert Southwest continued. By period’s end a disturbance moving east through the Great Basin brought favorable migration conditions in its wake in the Pacific Northwest, with moderate to locally heavy flights ensuing in the northerly flow.

Top Movers

Increasing

Species Increase from Last Week % of Checklists Reporting
White-crowned Sparrow 102% 20.7
Golden-crowned Sparrow 1653% 4.8
Violet-green Swallow 127% 9
Yellow-rumped Warbler 83% 15.8
Lincoln's Sparrow 132% 8.4
Fox Sparrow 533% 4.3
Vaux's Swift 127% 6.2
Townsend's Warbler 109% 7.4
Northern Flicker 35% 27
Say's Phoebe 72% 10.1
Black-throated Gray Warbler 89% 7.8
Ruby-crowned Kinglet 119% 6.4
American Pipit 140% 4
Orange-crowned Warbler 52% 16.7
Spotted Towhee 41% 19.8
Red-tailed Hawk 34% 23.7
Turkey Vulture 30% 27.6
Cackling Goose 4199% 1.8
Greater White-fronted Goose 469% 1.6
Merlin 159% 1.9
Sharp-shinned Hawk 97% 3.7
Red-shouldered Hawk 45% 7.4
Ring-necked Duck 145% 1.8
Pacific-slope Flycatcher 61% 5.1
Black Phoebe 22% 25.4

Decreasing

Species Decrease from Last Week % of Checklists Reporting
Caspian Tern -59% 3.2
Western Kingbird -72% 1.2
Black-chinned Hummingbird -54% 2.7
MacGillivray's Warbler -51% 2.3
Heermann's Gull -50% 2.4
Semipalmated Plover -52% 1.7
Brown Pelican -42% 3.9
Rufous Hummingbird -50% 2.1
Western Sandpiper -37% 4.4
Western Gull -30% 7.4
Black-headed Grosbeak -46% 2.5
Brandt's Cormorant -45% 1.8
Wilson's Phalarope -70% 0.5
Hooded Oriole -62% 0.8
Spotted Sandpiper -35% 3.9
Cliff Swallow -57% 1
Elegant Tern -46% 1.3
Swainson's Thrush -44% 1.6
Baird's Sandpiper -48% 1.3
American Avocet -37% 2.3
Black-necked Stilt -34% 3.1
Least Sandpiper -29% 5.7
Lesser Yellowlegs -43% 1.7
Barn Swallow -17% 17.5
Western Tanager -21% 7.9

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Farnsworth and Van Doren

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