Ready for Take-off?
Observers in the Gulf Coast states are on the lookout for the season's first orioles. Many ruby-throated hummingbirds, also a neotropical migratory songbird, have already arrived as you'll read below.
As waves of songbirds prepare to make their spring journey, what might you see if you were standing on their staging grounds? What's happening on the coast of Mexico's Yucatan Pennisula, for example? Many songbirds return from Central America by taking a short-cut back to their breeding grounds, flying non-stop over the Gulf of Mexico. Take out a map and you'll see why. As the "crow" flies this is the most direct route--but it's also risky.
These staging grounds might remind you of a busy airport, full of planes preparing for take-off. Here's a wonderful description by the Houston Audubon Society, "Millions of songbirds push north to the Yucatan Penninsula and the adjacent Mexican coast. As the sun sets on a spring evening, the birds assemble into flocks along the shores. The flocks remain for only a short time, busily feeding and calling in their short characteristic chirps. Then, the single chirp of an anxious individual bird sends hundreds onto the air to begin a night journey across 600 miles of open water."
Challenge Question # 70:
"Why do you think most neotropical migratory songbirds migrate at night?"
To respond to this Challenge Question please follow the instructions at the end of this report.
Weekly Weather Forecast for the Birds
Journey North student Katie N. wrote last week to ask about the effect of weather on migration:
"I am researching examples of where adverse weather conditions stopped or slowed the migration of robins, orioles and monarch butterflies. Please share where, the type of weather and the result to the animal." (Journey210@aol.com)
Over the next weeks, we're lucky to have the help of ornithologist David Aborn of the University of Mississippi who will provide a weekly "Weather Forecast for the Birds". He will show you how to read a weather map for a bird's-eye view of migration conditions. We've now setting up a network of on-the-ground observers in the Gulf Coast States. These people will notify you when the songbirds arrive and will comment on the affects of weather on migration.
Why Take the Trip?
In our last report we asked why orioles and other neotropical migratory birds leave the neotropics and come to North America. Here are some ideas from a New York student: "The weather gets too warm, out of habbit, following their prey, and predators might come after them." ccarlsen@monroe.edu
We'll come back to this question over the next weeks. Keep track of the reasons you think they make the trip. Think about the songbirds' life cycle at this time of year. If you have a Journey North Teacher's Manual, this would be a good time to do the "Life Cycle Slueth" on page 73.
Range Expansion
As it happens, some orioles don't leave the U.S. in the fall at all. During this century, as people have begun feeding birds, the migration patterns of many species have changed. Orioles are an example of a species that has expanded its winter range. Here are comments from Noel Wamer of Tallahassee, Florida:
March 25, 1996
"I suspect that you are looking for spring migration arrival dates of orioles, but I thought you might want to know about wintering birds as well. This winter I have had an estimated 25 orioles visiting my backyard feeders. This is the highest total in the past four winters. I will try to send along the date of last departure. They ususally begin to thin out in early April.
The phenomena of wintering orioles on the lower coastal plain was first noticed in the late 1940's. By the 1960's there were quite a few people feeding them. They are here every winter, but unless you feed them they are rare, scattered, and seldom seen. The orioles arrive in the neighborhood in mid-October, but will not come to the feeders until it becomes cold, usually after the first good freeze.
This winter has been uncommonly cold, even for Florida. The orioles respond by really flocking to the feeder. At the feeder they eat oranges cut in half, crumbled sugar donuts, peanut butter, and and orange suet mix. They will also drink from the hummingbird feeders. On days with sub-freezing temperatures the orioles were eating as many as nine orange halves a day, and as many donuts as I would put out.
Cheers,
Noel Wamer
Tallahassee, FL, USA
nwamer@freenet.tlh.fl.us
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Migration Reports from Observers
Collected from Journey North participants and the National Birding Hotline Cooperative.
From TEXAS:
March 26, 1996
A RUBY-THROATED HUMMINGBIRD was seen on the 26th in the Austin area.
Reports of hummingbirds are coming in, so if you don't have your
feeders out yet, it's time to do so. By April 2nd there had been
numerous reports of RUBY-THROATED all over town.
From LOUISIANA:
April 3, 1996
Grand Coteau, LA
We are located 15 miles north of Lafayette, Lousiana, about 50 miles
from the Gulf Coast. We have four resident hummers (ruby-throated)
at feeders outside of the classroom window. We have also spotted
barn swallows, and today spot-breasted thrushes. Weather Conditions
lows in the upper 40's high's in the mid 70's
Latitude 30. 418, Longitude -92.044
Thanks, Mary Jo Kirgan mkirgan@ash10.net-connect.net
How to Respond to Challenge Question # 70
1. Address an e-mail message to: jn-challenge@learner.org
2. In the Subject Line of your message write: Challenge Question #70.
3. In the Body of your message, answer this question:
"Why do you think most neotropical migratory songbirds migrate at night?"
The Next Northern Oriole Migration Update Will be Posted on April 11, 1996.
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