Here's the latest from whooping crane headquarters--and at points along the cranes' 2,700 mile path back to their nesting grounds in Canada. Thanks to Tom Stehn and Wally Jobman of the U.S. Fish and Wildlife Service for preparing these reports.
To: Journey North
From: Tom Stehn,
U.S. Fish and Wildlife Service
Aransas/Matagorda Island National Wildlife Refuge Complex
Austwell, Texas
Dear Students,
The migration is fully underway, with 82 whoopers (52 % of the flock) headed for Canada. This is about a week ahead of departures in some years. Fifteen of 27 family groups have left their wintering grounds here on the Gulf of Mexico. Among them is the Nylarling pair, who started their migration on April 3 or 4th. (This is the pair people are most likely to see when they visit our refuge. They're named after the Nyarling River which flows beside their nest in Wood Buffalo National Park in Canada.)
With a low pressure system bringing north winds to the coast March 31-April 1, most of the cranes probably started their migration April 2-4. Strong southeast winds and thermals April 3rd provided ideal migration conditions.
Easter weekend, another strong low pressure reached the Texas coast, bringing much needed rain along with thunder and even hail stones. This was the first real rainstorm we have had in over 3 months. These low pressure systems are continuing to arrive in South Texas every 6-7 days. I hope national weather patterns change because the migrating whoopers will have to travel through these storms which are strong blizzards in the northern U.S. and Canada. I did a radio interview with Regina, Saskatchewan last week comparing their snowstorm with our 75 degree temperatures at Aransas.
When the migrating whoopers encounter these storms with their north winds, the birds will quickly find a place to land and wait for several days until the north winds rotate back around to the south. Storms (low pressure systems) bring winds from the north as the winds whirl counterclockwise around the pressure system. During high pressure, this brings southeast winds to Texas. The whoopers wait for high pressure and south or east winds to continue their migration. During these storms, the whoopers will make short daily flights out to grain fields to feed, returning to wetlands where they will spend the night. It is during these short low altitude flights where they might collide with power lines and be killed, especially during rain or snow storms when the power lines are not very visible.
Right now at the refuge we have two chemical spills to contend with. Oil washed up on 25 miles of beach from a barge 150 miles up the coast that split in two in bad weather. We had over 150 people working on the beach last week picking up tar balls the size of dinner plates. We have found 20 dead birds killed by the oil and captured two loons that were weakened by the oil.
While this was going on, a tanker in the Gulf opened the wrong valve and dumped 580 barrels of tetrachloroethylene (a chemical used in making degreasers and nail polish removal) over a 20-mile strip until the crew discovered their mistake. This chemical is heavier than water and kills anything it comes into contact with as it sinks to the bottom in the 90-foot deep water. There is probably no way to clean up this latter spill. I wonder if any endangered sea turtles were killed in the spill? We will look for dead fish washed up on the beach, but the spill occurred 18 miles off-shore so things may not turn up on the refuge.
Fortunately, neither of these spills directly affected the whooping cranes that were still here. However, how many small larval blue crabs in the Gulf were killed by the chemicals. These very young crabs are what the whoopers will rely on for food next fall as the crabs grow and move into the salt marshes. So these spills do affect the whoopers. It is a lesson in how impacts occurring in an ecosystem affect many things.
I expect all but 20-30 of the whoopers will have departed Aransas when I next do an aerial count scheduled for April 11.
Sincerely,
Tom Stehn
Aransas Refuge Biologist
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From: Wally Jobman,
U.S. Fish and Wildlife Service
Grand Island, Nebraska
Subject: Whooping Crane Sightings in The U.S.A. Spring, 1996
Date..............Location
O4/03/96..........OKLAHOMA
.....................Alfalfa County., ( near Jet)
.....................7 Cranes
04/04/96..........OKLAHOMA
.....................Alfalfa County.,( near Jet)
.....................11 + 1 Cranes
03/13/96..........KANSAS
.....................Stafford County., (Stafford)
.....................2 Cranes
04/05-06/96.......KANSAS
.....................Rush County (South of Otis)
.....................4 + 1 Cranes
03/27/96..........NEBRASKA
.....................Custer County (North of Merna)
.....................2 Cranes
03/30/96..........NEBRASKA
.....................Buffalo County (West of Kearney)
.....................1 Crane
04/07/96..........NEBRASKA
.....................Garfield County (near Burwell)
.....................2 Cranes
04/07/96..........NEBRASKA
.....................Phelps County (West of Wilcox)
.....................2 + 1 Cranes
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