Oriole Migration Update: April 24, 1997

Jim Gilbert

Until an hour ago, sightings of only 3 orioles had been posted on the Internet. Then, this exciting news arrived from David Aborn in Texas. As you'll read below, a huge wave of migrating songbirds landed Tuesday on the Texas Gulf coast. Riding on a south wind, they had presumably just crossed the Gulf of Mexico when they encountered strong winds from the north and were forced to land.

When migrating birds stop en mass due to bad weather, it's known as a "fallout". Accurate timing is critical when songbirds cross the Gulf of Mexico. When there's a fallout on the Texas coast we know many other birds will not cross the 500 miles of open water successfully. And, although those that arrive may stay for only a few hours each year, their lives may depend on the coastal woodlands for food and rest.

They'll be coming your way soon! So be on the lookout, and report back to us when you see your first oriole this spring!

Here is David's report:

Dear Students:
"I spent Tuesday morning (4/22/97) in the field looking for birds. A cold front passed through at about 6:00 AM, bringing 20 mph northwest winds. Had the front passed through at about midnight, this morning would have been great for birding. However, the south winds during the night allowed birds to migrate, so this morning was slow. I did hear the first Swainson's Thrush of the season, and saw Nashville Warblers, a Great-crested Flycatcher, and two Ruby-throated Hummingbirds.

"Later, I received a report from the Texas coast. The front that passed through central Texas Tuesday morning made it to the coast that afternoon. It forced MANY migrants to land, including 50+ orioles. Other seen in big numbers were 50+ Indigo Buntings and 30+ Painted Buntings."

Tuesday Morning (April 22 at 6 AM)	Tuesday Evening (April 22 at 6 PM)

These maps show the weather conditions that caused the "fallout" on the Texas coast. (The yellow arrows show the direction from which the wind was coming.) The fallout occurred near the Texas/Louisiana border, at Sea Rim State Park, about 20 miles south of Port Arthur, TX. Look at the arrows there. As you can see, the wind was blowing from the south in the morning. Note how the wind shifted and was coming from the north in the afternoon.

"If you look at today's weather map, a strong storm system is in the northwest. This front is expected to pass through Texas on Friday and continue moving east. Just like Tuesday's front, it will bring bad flying weather for birds, so depending on where you live, this weekend or early next week should have lots of migrants.

"You asked if I think this is the first 'wave' of orioles, since there haven't been many reports. Yes, I do think this is the start of the Northern Oriole migration (Orchard Orioles migrate a little earlier). Along the Gulf coast, Northern Orioles usually show up around the last week in April, so this is the right time to see an increase in their numbers.

"The third week of April through the first week of May are usually the peak of migration along the Gulf coast, so the next couple of weeks should be pretty colorful. Feel free to ask me any questions you have about birds or bird migration. Until next week, happy birding!

David Aborn
David_aborn@baylor.edu

The Next Oriole Migration Update Will be Posted on May 8, 1997.