Migration Forecast: 30 March – 6 April 2012

Benjamin Van Doren The Cornell Lab Mar 30, 2012

Conditions across much of the West look favorable for light migration to occur during the course of the forecast period, particularly toward the end of the week. The distinct exception is the Pacific Northwest, which is again forecast to receive more precipitation that will hinder significant landbird movements. The Great Plains will experience a distinct pulse of migrants early and late in the week. Watch midweek for the possibility of southern Plains fallouts associated with a frontal passage. Although the weekend begins with a potential for fallout conditions in the Great Lakes region, conditions are likely to be poor for migration for much of the rest of the week from the Great Lakes east through New England. Southern and western extremes of the region may see movements by late in the week, as might southern portions of the coastal Northeast. The Gulf Coast and Southeast should experience moderate migration in many areas over the course of the coming week, with a possibility for fallouts associated with a frontal passage across many coastal areas from Texas to Florida.

See the week’s radar results here.

Links to species names below take you to the March eBird maps for 2012.

Red-naped Sapsucker

Red-naped Sapsucker


North America’s four species of sapsuckers will be on the move this week, returning to higher elevation breeding locations and stopping over at migrant traps. Look for them in places where warm temperatures and southerly winds meet advancing precipitation from the north and west. The long-distance migrant and northern breeding Yellow-bellied Sapsucker should be on the move across a broad front east of the Rockies. Look at this migration graph for Wisconsin. Talk about arrival! But the more enigmatic three western species are all shorter-distance migrants, and their migration patterns are poorly understood, yet they should still depart lowland areas of the Pacific Coast and Southwest this week, pushing north toward their breeding grounds. Check out how closely this breeding range map for Williamson’s Sapsucker mirrors the high elevation habitat that it prefers for breeding, yet it does not occur in the coastal mountains of West. Instead it is replaced there by the Red-breasted Sapsucker, which prefers the more humid conditions of the Pacific Northwest stretching north to southeast Alaska. The closely related Red-naped Sapsucker’s distribution is similar to Williamson’s. All four of these woodpeckers should be on the move for the next 2-3 weeks, so the time is right to start your sapsucker search.



The Pacific Coast begins this forecast period with unfavorable conditions for migration in most areas, although portions of southern California and Nevada, the Great Basin, and northern and eastern Rockies will likely see light movements. As the precipitation and northerly winds associated with the stormy Northwest gradually expands eastward, most bird movements west of the Rockies will shut down, except across the desert Southwest, where light movements will continue. The beginning of the week sees continued unfavorable conditions along the coast for landbird migration, although some portions of the northern Central Valley in California and the Great Basin may see light movements. By the middle of the week, conditions begin to improve for light migration across portions of the desert Southwest north through the Great Basin and east through the Rockies, continuing through the end of the week.  However, note that more northerly locations will likely see migration halt as the weekend begins with the next expansion of continued Pacific Northwest storminess moving into the region. Conditions in some areas of the Great Basin and northern Rockies may provide opportunities for birders to see waterfowl and swallow fallouts on water bodies, particularly in areas where light or southerly winds are forecast to interact with precipitation.

  • Western landbirds will continue to move up the West Coast this week. Watch forBlack-headed Grosbeak to appear in southern and central California this week, but it’ll be another two weeks before they really reach the Pacific Northwest, and another month before they fill in their breeding range throughout the Rockies. Check out how they fill in the West Coast in April, but don’t get into the core of their range in the Interior West until May. This general pattern of earlier arrival on the West Coast can be seen in many western migrants, and is also discussed in last week’s BirdCast migration report.
  • Vaux’s Swifts should appear locally in southern Arizona and in parts of California this week, but colder temperatures and continued precipitation in the Pacific Northwest should prevent their arrival in Oregon and Washington at least for a few more weeks.
  • Mountain Quail will be in evidence as males begin to crow incessantly from their territories and conditions begin to warm up in their higher elevation breeding areas.
  • The mysterious Mountain Plover should be moving from its wintering grounds in California to the Great Plains this week, but exactly how they get there is still poorly known. Enterprising birders should look for storms and inclement weather to potentially put down migrants in Nevada and Utah this week. Look on salt flats and other barren open landscapes for this species. See Great Plains discussion below.
  • Lawrence’s Goldfinch is another bird to watch out for this week in California and the Southwest. Lawrence’s movements are poorly known, and the species appears to be nomadic in some years though not in others. This winter saw decent numbers arrive in the Southwest, so look for these birds to be returning to California’s foothills in the coming weeks. If you’re birding the desert migrant traps in the coming weeks, keep an ear out for Lawrence’s Goldfinches overhead, giving their distinctive, yet difficult to hear, high-pitched “tinkling bells” flight call.


Great Plains

Conditions in the southern Plains states look favorable for moderate migration over the weekend, with scattered heavy migration in Oklahoma, Nebraska, and Kansas. However, the northern Plains states may not see these conditions until Sunday and Monday. Additionally, conditions look good for diurnal movements to occur (strong thermals and warm conditions), so birders should watch for migrating soaring birds to be aloft early in the forecast period. By Tuesday, as precipitation moves eastward across the northern Plains states, migration will shut down; however, southern portions of the Plains states including the Ozarks should see continued favorable conditions for movements, including the potential for fallouts in Oklahoma and Nebraska. Birders should check landbird and waterbird migrant traps. With the arrival and passage of a frontal boundary, and increased likelihood of precipitation, conditions in the middle of the week will not be favorable for migration in most areas (light movements may be widely scattered and local in the northern Plains states). By Thursday and Friday nights, southerly flow will return across much of the southern Plains region, likely facilitating widespread moderate and scattered heavy movements. Friday looks to be a good day for watching the sky during the day, with the best chance on this day to observe diurnal migration in action, including soaring migrants and swallows.

  • The first week of April should bring the first influx of Swainson’s Hawk ‘s into Colorado and western Kansas, and should bring some into Wyoming and Nebraska. Swainson’s will also be evident in good numbers at hawkwatches in southern Texas. There have been scattered reports of this species as early as February and the first week March from Colorado — some with good descriptions. We encourage people to photograph early arriving Swainson’s Hawks to help understand the true status of this species.
  • Farther north, expect a big movemen t of Red-tailed Hawks through the northern plains and prairie provinces, particularly on Sunday and Monday. Head to hawkwatch sites such as Pembina Valley, near Winnipeg, Manitoba, if you can.
  • Expect Mountain Plovers to return to breeding grounds in Colorado, Kansas, and New Mexico. This species is rarely detected as a migrant, but this would be an excellent week to look. In particular, try searching during or immediately following rain or snow that may force the species to land. Look on bare ground, open agricultural fields, near prairie dog colonies, or other areas with very short grass. Prior to fall migration, they congregate in dry lake beds and along dry shorelines of reservoirs, and these would be excellent locations to check for downed spring migrants as well.

Upper Midwest and Northeast
The weekend begins with favorable conditions in the Upper Midwest on Saturday evening for moderate migration to occur, with the potential in portions of the Great Lakes for scattered heavy migration. However, precipitation quickly enters the picture and because of rapid changes in wind direction and the potential for some widespread precipitation, birders should be aware of the potential for landbird and waterbird fallouts, particularly around the Great Lakes. As this disturbance passes, conditions across the Great Lakes will be mostly unfavorable for migration through Monday. Farther south, conditions are slightly more favorable for migration, and areas of the upper Mississippi Valley may see light to moderate movements continue through Tuesday. As precipitation builds into the region, and a stronger disturbance approaches, conditions will likely deteriorate for nocturnal migration through much of the period until Thursday night; however, birders should be aware of the potential for fallout conditions in areas where southerly flow and presumably light to moderate migration interacts with precipitation. By Thursday night, western portions of the region should begin to see more widespread moderate movements, although by Friday night, only southern portions of Ohio, Kentucky, and Tennessee will likely see these movements as northerly flow continues over the Great Lakes. Most of the Northeast looks to be in for another round of northerly flow and precipitation through the forecast period, though light to moderate migration is possible, even in these circumstances, if precipitation does not occur and winds are lighter than forecast.  Additionally, a westerly component to forecast winds may make for interesting coastal landbirding across New Jersey, New York, and southern New England by the end of the forecast period. Most movements of nocturnal migrants, if they occur, will likely be in the Delmarva region and over portions of Pennsylvania.

  • Stormy conditions early in the week appear poised to force down Long-tailed Duck,Horned Grebe, and perhaps even a few White-winged Scoters moving between the Atlantic Ocean and Great Lakes. These species can even show up on ponds during inclement weather, so get out and check ponds, lakes, and other water bodies for these waterbirds. The extent of overland migration for Long-tailed Duck, in particular, is under-appreciated by most birders. Note the pattern of observations between major wintering areas from the Chesapeake to New England, and staging areas in the Great Lakes (where they also winter). Seriously. This is very cool. Click this link. And compare with January and February of this year. You can also listen for migrating Long-tailed Ducks calling as they fly overhead at night.
  • Expect a nice push of both species of kinglets in the region. The first Ruby-crowned Kinglets have already shown up in most states and Ontario–expect the species to become more widespread this week, perhaps with some localized fallouts along the Great Lakes. Golden-crowned Kinglets should approach near peak numbers in the Great Lakes states. Winter Wrens have also already moved in record numbers and we expect this week will be near peak numbers across much of the region.
  • Yellow Palm Warblers should arrive as conditions permit, particularly on the coast. Yellow Palm Warblers typically arrive and peak two weeks ahead of Western Palm Warbler. Savannah Sparrows and Chipping Sparrows should become increasingly widespread. While still about a week early, watch for Blue-gray Gnatcatcher andLouisiana Waterthrush to fill in territories. Watch for early Ovenbirds too, reaching the mid-Atlantic (see discussion below).

Gulf Coast and Southeast

Favorable conditions across Texas and the western Gulf Coast will likely facilitate moderate migration, with scattered heavier movements.  This pattern begins the weekend and continues through Tuesday, when a frontal boundary is forecast to approach and pass. With the threat of precipitation increasing through Tuesday night, and a potential for wind shift during the day on Tuesday, birders should be aware of the potential for coastal fallout of circum-Gulf and trans-Gulf migrants.  Conditions for fallouts are forecast to continue to move eastward along the Gulf Coast, providing birders opportunities for trans-Gulf groundings in MS, AL, and the panhandle of Florida.  By Wednesday, northerly flow in the western portions of this region will likely shut down most movements there, although conditions in FL and AL remain interesting for potential fallouts and at the least moderate migration over land.  Additionally, note that trans-Gulf movements will likely shut down as this front moves out into the Gulf of Mexico and pushes East toward the northern Caribbean. The East coast of Florida should see good conditions for concentrating migrants by midweek, as a westerly component to the forecast winds should develop though Thursday night.  By Friday, the frontal boundary is forecast to pass off the coast, leaving much of the Southeast under the influence of unfavorable northerly winds.  Additionally, most migration from the Caribbean will cease as this front moves off the coast.  However, western portions of the region should see widespread moderate migration by Thursday night after southerly winds return.

  • Chimney Swifts have already been widely reported in the Gulf Coast states with scattered reports from Arkansas, Tennessee, and the Carolinas. Expect numbers to build through the week with potential first arrivals for Kentucky and Virginia. Will conditions be favorable enough to take them as far as Maryland? It’s a roll of the dice, but given the excellent eBird community in that state, we’re not willing to bet against them, so we’ll predict first arrivals before the end of the week.
  • Expect a strong arrival for Ovenbird, which seems to already be showing signs of arrival on the Southeast coast. Could these be birds moving from Florida and the Caribbean, a tad earlier than trans-Gulf migrants coming from Middle America? Records are currently limited to Florida (where widespread away from the panhandle), a few in Texas and isolated reports from Louisiana, Georgia, the Carolinas, and Virginia. Numbers should build considerably in all Gulf Coast states, and we wouldn’t be surprised if the first few show up in Tennessee, and more arrive in the Carolinas and Georgia. Kentucky and the mid-Atlantic may need to wait another week, but please try to prove us wrong!
  • Blue-headed Vireos will be found in good numbers throughout the region including an influx of birds that wintered in Mexico and Central America. White-eyed Vireosshould be widely found away from wintering grounds north to at least the mid-Atlantic and Kentucky.
  • Texas should see a notable influx of flycatchers including Scissor-tailed Flycatchers, Eastern and Western Kingbirds and Brown-crested, Great Crested, and Ash-throated Flycatchers.
  • Along the immediate Gulf Coast expect the next wave of warblers to include Blue-wingedTennessee, and Kentucky, some of which will also occur inland.Swainson’s Warbler may be found at coastal migrant traps, but may be just as easy to find on the breeding grounds.
  • Birders in Bermuda should be aware of the possibility for an arrival of early Caribbean migrants associated with the strong frontal boundary forecast to push off the Southeastern US coast by late week. Southwesterly winds in advance of the passage of this front may push birds moving through the Caribbean substantially East of their intended landfalls. Presumably arrivals could occur during the 6-8 April period if this happens. Birders should watch the passage of this front carefully, and examine the timing and extent of its preceding southwesterly and westerly winds to assess how likely a possibility this might be.  Perhaps an even more remote possibility is the transport of some of migrants much farther afield toward the Canadian maritimes, depending on the tracking and intensity of the system. Although there is no precedent, we wonder aloud if the right winds could even transport spring Hooded Warblers, Blue Grosbeaks, or Summer Tanagers to Iceland. A mega-twitch would surely ensue if so!

Posted 23 March 2012 by Christopher Wood, Andrew Farnsworth, Brian Sullivan and Marshall Iliff of the Cornell Lab of Ornithology and David Nicosia of NOAA, on behalf of Team eBird and BirdCast.