Spring migration has reached fever pitch across the mid-continent, with millions of songbirds returning from the Neotropics. Our orioles for example, have now been reported in 14 U.S. States and 2 Canadian Provinces, up from only 7 States last week. The ruby- throated hummingbird migration is also humming along! They've now been reported in 17 States.
David Aborn sent his final weather report today, and says migration is beginning to slow down along the Gulf Coast. As you read his report, see if you can find the weather patterns he describes on this weather map.
Invasion Across U.S. Border
Exactly how many migrants have arrived from the Neotropics over the
past few weeks? In an article called "Silence of the Songbirds"
(National Geographic: June, 1993), a scientist named Dr. Sidney
Gauthreaux was asked this question. He estimated that, at peak
migration in late April, as many as 45 million songbirds arrive in a
single night along a 300 mile stretch of coastline between Corpus
Christi, Texas, and Lake Charles, Louisiana.
How does he know this? Since the 1960's he has used radar to measure migration across the Gulf of Mexico. You can see pictures of this in National Geographic--check it out!
Enough Food For an Army?
As the migratory population of our entire continent comes north to
breed, what do they eat aong the trail? Take a close look at
available food resources and you'll have a clue. According to John
Terbourgh, a Professor of Biology at Princeton University, "The
banquet is so bountiful and obvious that we do not have to wonder
what fuels the northbound migration."
In his book, "Where Have All the Birds Gone?" (1989, Princeton University Press) he explains his theory:
"The main surge of Neotropical migrants moves northward in phase with the leafing out of the forest canopy. The timing is hardly coincidental, because the larvae of several species of defoliating insects hatch out in synchrony with bud break to take advantage of tender, protein-rich young foliage. For several weeks thereafter, these (geometrid moth) larvae, commonly known as 'inchworms', can be extremely abundant and in outbreak years can even strip the canopy of leaves."
While estimates are very difficult to make, most people agree that, in the case of many songbird species, fewer and fewer make the trip each year. Again quoting from National Geographic, "Sidney Gauthreaux's comparison of radar images suggest a 50% falloff since the 1960's in waves of spring migrants."
Students in New Jersey who are concerned about songbirds sent this note yesterday:
"New Jersey is a very important state for migrating birds. We are on the Atlantic Flyway. That's where birds fly when they're coming North (along the Atlantic Coast). People are building houses where the salt water marshes used to be, and over wetlands and fields and forests too. New Jersey is more crowded with people than any of the other 50 states. The birds don't have any habitat. It's happening in other states too." Mrs. Hayes' Class, Tenafly, N.J. Smithread@aol.com
In next week's report we'll summarize the challenges that migratory songbirds face--on the wintering grounds, on the breeding grounds and along the migratory trail. In preparation, see if you can find the answer to this Challenge Question:
Challenge Question: #114
"What is a parasite? Describe how cowbirds parasitize some
Neotropical migratory songbirds."
(To respond to this Challenge Question, please follow the instructions at the end of this report. )
*****************************************************
To: Journey North
From: David Aborn,
University of Southern Mississippi
Dear Students:
Well, spring migration down here is coming to a close. There is a
stationary front that extends from Oklahoma all the way to the
mid-Atlantic states. South of the front, the winds have been from the
south. It has been that way for the last week. Consequently, it has been
pretty slow at our study site. There have been some orioles, and good
numbers of Bobolinks. In Hattiesburg, I have been seeing lots of Red-eyed
and Yellow-throated Vireos, Summer Tanagers, and Wood Thrushes.
As migrants reach the area where the front has stalled, they encounter rain and storms. If the winds are strong enough and the rain heavy enough, the birds will be forced to land. Thus, there should be a line of bird fallout that extends from the plains to the mid-Atlantic. Once the weather clears, the birds will take off again.
I hope you have enjoyed learning about this year's migration, and I hope your interest in nature continues. There is much we do not know about the world around us, and we need enthusiastic people like you to help answer the many questions that exist about our environment.
See you next migration!!
David A. Aborn
***********************************************************
The Following Migration Sightings Collected by the Volunteers of the National Birding Hotline Cooperative and Journey North:
NORTHERN/BALTIMORE ORIOLES
From PITTSBURG AND W. PENNSYLVANIA:
April 24, 1996
Westmoreland County:4/24,NORTHERN ORIOLE at Keystone State Park (North of
Latrobe).
From PENNSYLVANIA:
April 28, 1996
At the John Heinz National Wildlife Refuge, aka Tinicum (South of
Philadelphia), on Sunday, April 28th , there was a BALTIMORE ORIOLE seen.
From VIRGINIA:
April 28 & 29, 1996
Baltimore Oriole 4/28/96
Fairfax Co., VA
1 at Huntley Meadows (Near Arlington).
Baltimore Oriole
Charlottesville,VA 4/29/96
1 on UVA campus. New arrival.
From TENNESSEE:
April 30, & May 1, 1996
At Warner Park in Nashville on April 30 there were 49 species seen with 14
warbler species, but the most spectacular sight was all orange and
black...5 male BALTIMORE ORIOLES all seen together.
An NTOS Wednesday Walk at Radnor(Nashville) on May 1st produced 70 species, 23 warbler species and 4 vireo. Including 2 BALTIMORE ORIOLES.
From NEW JERSEY:
May 1, 1996
Great Swamp (West of Newark) May 1 at the Green Village end of Meyersville
Rd., NORTHERN ORIOLE were around the swamp.
(Credit: New Jersey Audubon Society)
From OHIO
May 1, 1996
The Soil & Water Conservation District Area 5 Envirothon team saw 2
Northern Orioles on May 1st at Shawnee State Park near Portsmouth, Ohio.
Portsmouth is the Southern most part of Ohio. John Austin
jaustin@delnet.net
From DELAWARE:
May 1, 1996
Arrivals at Burrow's Run near Ashland (NW of Wilmington) on Wednesday
including BALTIMORE ORIOLE.
From Hamilton/Ancaster, ONTARIO:
May 1, 1996
New migrant sightings this week include a NORTHERN ORIOLE.
We're all waiting for the warblers. Look for a push of warmer air
from the south, especially if it rains during the night.Good Birding.
From NEBRASKA:
May 2, 1996
On the 2nd, a BALTIMORE ORIOLE was seen in Whispering Timbers housing area
south of Fontenelle Forest, in Bellevue (South of Omaha) & a RUBY-THROATED
HUMMINGBIRD was seen in yards in central Bellevue (South of Omaha).
From MASSACHUSETTS:
Nantucket Island
May 2 & 5, 1996
All sorts of exciting springtime sightings to tell you about including: On
5/2 an excited new birder spotted a NORTHERN ORIOLE (Baltimore)in her yard
in Tom Nevers (South of Nantucket).
A check of the "Oriole Tree", a large pink flowering cherry on the left hand side of Sconset Avenue two streets before the rotary in Sconset (Nantucket Island) on 5/2 found a male NORTHERN ORIOLE (Baltimore), and an [AMERICAN] GOLDFINCH. A recheck of this same tree during our bird walk on 5/5 revealed to our amazement, a HUMMINGBIRD (most likely a RUBY-THROATED.)
From NEW JERSEY:
May 3, 1996
Rory saw a female Northern Oriole at 7:00 this morning, in his backyard.
The Oriole Committee, Tenafly, N.J. Smithread@aol.com
From CENTRAL AND NORTHERN RHODE ISLAND:
May 3, 1996
In Cumberland:(North of Providence) 1 NORTHERN ORIOLE.
From MASSACHUSETTS:
May 3, 1996
Eastern Massachusetts
At Heard's (sp?) pond in Wayland (West of Cambridge) there was a Baltimore
Oriole.
At the Oxbow National Wildlife Refuge there was a Baltimore Oriole.
From NOVA SCOTIA:
May 3, 1996
Baltimore Oriole (Icterus galbula)-One at White's Lake (South of
Halifax) May 3.
From ILLINOIS:
Chicago area
May 3, 1996
Among 91 species seen today in Jackson Park (Chicago area) were BALTIMORE
ORIOLE and BOBOLINK.
From ILLINOIS:
May 4, 1996
Among 106 species seen today in Jackson Park (Chicago area) was a
BALTIMORE ORIOLE.
From PENNSYLVANIA:
May 5, 1996
Two orioles sited in back yard Sunday 5/5/96. Both appeared
to have the coloration of males. I hope a nest becomes
established so that I may enjoy them all summer.
Location: Sunbury, Pa. 3 miles east of the Susquehanna river.
William C. LeMasters 9i11@postoffice.prolog.net
RUBY-THROATED HUMMINGBIRDS:
From NORTH CAROLINA:
April 21, 1996
Ruby-throated hummingbirds have been seen for a couple of weeks throughout
the state. Liz Baird, a Museum educator here in Raleigh, spotted a
hummingbird at her feeder in mid-March. My first observation was on 4/21 - a
male feeding on wild columbine growing in my wildflower garden. Several other
folks have recently reported hummingbirds at their feeders and at wildflowers
such as the native coral honeysuckle (a great hummingbird plant!).
Mike Dunn
Coordinator of Teacher Education
North Carolina State Museum of Natural Sciences
Raleigh, NC
MikeDunn@aol.com
From ILLINOIS:
April 23, 1996
A RUBY-THROATED HUMMINGBIRD was at Carlinville (Near Springfield) on
April 23.
From PITTSBURG AND W. PENNSYLVANIA:
April 27, 1996
Butler County: 4/27 a RUBY-THROATED HUMMINGBIRD was seen on a feeder in
Slippery Rock (NE of New Castle).
(Numbers of YELLOW-RUMPED and RUBY-CROWNED KINGLET reported at Presque Isle are down suggesting migration is later than usual.)
From PENNSYLVANIA:
April 28, 1996
At Camp Michaux, Michaux State Forest (SW of Harrisburg) there was a
RUBY-THROATED HUMMINGBIRD.
From OHIO:
May 1, 1996
Several RUBY-THROATED HUMMINGBIRDS were reported beginning with 1 in
Hubbard ( NE of Youngstown) on May 1st.
From Cape May NEW JERSEY:
May 3, 1996
RUBY-THROATED HUMMINGBIRDS are BACK!!! A male is visiting the
feeders and gardens regularly now at CMBO. Males return first
and set up territories, then females follow. If you want
hummingbirds to stay and nest in your yard, you may want to hang
feeders now, especially since gardens are pretty sparse this
time of year. But realize the task you are taking on ...
feeders need to be cleaned out thoroughly each week and refilled
with fresh solution. In the spring you only need to put 1-2
inches of solution in your feeders.
Highbush Blueberries are beginning to bloom. And Dogwood flowers are just
opening. Flowering Quince or Japonica is in bloom, a favorite with hungry
hummingbirds. (Credit: Cape May Bird Observatory staff)
From Eastern MASSACHUSETTS:
May 3, 1996
RUBY-THROATED HUMMINGBIRDS in East Middleboro and East Bridgewater
(South of Brockton)
From NEW YORK:
May 6, 1996
Syracuse 50 mile radius
The first RUBY-THROATED HUMMINGBIRDS have been seen. It's time to
get those feeders out using a solution of 4 parts water to one part
sugar; red food coloring is not necessary.
****************************************************************
How to Respond to Challenge Question # 114
1. Address an e-mail message to: jn-challenge@learner.org
2. In the Subject Line of your message write: Challenge Question #114
3. In the Body of your message, answer this question:
"What is a parasite? Describe how cowbirds parasitize some Neotropical migratory songbirds."
The Next Northern Oriole Migration Update Will be Posted on May 16, 1996
 |
|
|---|
