As promised, this week Peter Nye sent migration data from the first eagle he ever tracked using satellite telemetry. This eagle was tracked in 1992. With the addition of this eagle you now have 3 eagles to track this spring.
Remember, even though this migration data is not "live" it does represent the real world at this moment. This very day, eagles are migrating according to the patterns you'll discover below. Each week we will provide satellite readings that were taken at EXACTLY this time of year in the 1992, 1994 & 1995 seasons.
Compare the migration data in the charts below for our 3 eagles and see if you can answer today's Challenge Question:
Challenge Question # 82
"When did each of our 3 eagles begin its migration? If the dates are different, what do you think this could mean? "
Accompanying today's report, Nebraska students describe how a local power plant serves as a "MacDonald's restaurant" for eagles that winter in their region. We hope you'll enjoy their story. Last week a mystery from Michigan was described by Mrs. Sabotta's students. They asked, "Why don't the eagles in Iron Mountain, Michigan migrate?"
Among those who puzzled over this mystery were Mrs. Allen's 4th Grade students at South Park Elementary in Pueblo, Colorado. Here's what they concluded: "The eagles are near Lake Superior. The lake is too large to freeze so the eagles have fish to eat all winter." (garyt@ns-1.csn.net)
But the students in Iron Mountain INSIST all the water there is frozen in the winter! So, how can the eagles survive if they can't get fish?
Jason Edstrom explains, "Road kill is the reason Eagles can stay in Upper Michigan year round. In the winter more deer and other animals get hit by cars than in the summer. In the summer they eat fish and in the winter road kill."
Lucas Baumgartner adds, "You see, the open water isn't the only thing that freezes. The roads also build up ice making it very difficult to stop so many animals are added to the road kill menu every winter. So even though the main source of food of the Eagle is fish, during the winter Eagles do not migrate because there is plenty of road kill to feed them."
** By the way, we challenged eagle expert Peter Nye to answer the same question. Here are his thoughts:
"Concerning the Michigan eagle migration question, I would guess that there is an available food supply in Iron River, allowing eagles to stay there. This could be in the form of fish coming out of a power-plant along a small stretch of the river, or from ice- fishermen leaving their catch on the ice, or from carcasses being left out by meat processing plants, or even from an upland source, not fish. For example bald eagles that over-winter in Utah feed primarily on jackrabbits! Whatever the reason in Iron River, they are there because they are getting food !! Let me know what they are eating, I'm curious.
"Remember that not all bald eagles are migratory in the true sense of the word. A better way to describe them would be as birds moving from one place to another as their food supply dictates. Some populations migrate, some do not. Some breeding birds stay on or near their nesting site year-round. The decision to migrate or not is based upon food. When the food supply dwindles or when access to a food supply becomes difficult, eagles will move to places where they can get some. This food supply does not always have to be fish, although that is preferred.
"Here's an update about our New York eagles. All of our 'local' New York nesting eagles are now incubating eggs, some of which should begin hatching out any day now. Just about all of the bald eagles that winter in New York State have now departed for their northern nesting grounds (the adults). I just had an interesting observation of one of our marked eagles. It wintered in southern NY (Sullivan County) and was seen at a deer carcass on the Upper Saranac Lake way up in our Adirondack Region of northern NY on 12 April.
"The movements of immature birds are different from the movements of breeding eagles. Not unlike immature Homo sapiens, immature eagles kind of do what they want, traveling wherever they are inclined, but not necessarily to any breeding territory or in any particular direction. We have observed, however, that young eagles often wander back to their natal (birth) territory each spring, at least for a while, perhaps as an "orienting" mechanism to refamiliarize themselves with where they came from. Of course when they reach sexual maturity at about 5 years of age, they will return to the "vicinity" from where they fledged to establish their own breeding territory or to fill a vacancy in an existing one. Male eagles will typically stay "closer to home" than females, who may establish their own nesting sites within 200-300 miles from where they were born.
"We are obviously disappointed that the eagle we caught and tagged this year suffered a failure of its satellite radio. We must remember though, that these radios are very high-tech and state of the art; they are not yet a perfectly reliable commodity. We hope to get several out next year, so we should have at least one or two operating."
Regards, Eagleye Nye
EAGLE MIGRATION REPORT FROM OBSERVERS:
(Please report your bald eagle sightings to: jn-report@learner.org)
From MINNESOTA:
Several students saw eagles over the Easter Holiday from April 5 to
9th. They were reported near large lakes which are still iced in
except for edges or along the rivers, mainly the Mississippi which
runs through our closest large town, Grand Rapids.
Mrs. Williams 3rd Grade Class
Vandyke Elementary
Coleraine, MN
0316vel@InforMNs.k12.mn.us
Samantha, Naomi and Tarayn of Mrs. Williams third grade class send this poem:
Eagle, Eagle soar through the sky
Eagle, Eagle I watch you fly
Eagle, Eagle hunts by day
Eagle, Eagle sees his prey
Eagle, Eagle has his fish
Eagle, Eagle now you rest.
Bald Eagle Spring Migration Data
1992, 1994 & 1995
1992 Eagle
Date Latitude/Longitude
Feb. 29 41.315 N, 74.716 W
March 2 41.522 N, 74.541 W
March 5 41.496 N, 75.032 W
March 9 41.558 N, 74.777 W
March 10 41.530 N, 74.719 W
March 12 41.581 N. 74.576 W
March 15 41.565 N, 74.741 W
March 16 41.639 N, 74.663 W
March 19 41.591 N, 74.495 W
March 21 41.495 N, 74.799 W
March 22 41.537 N, 74.447 W
March 26 42.094 N, 74.800 W
March 29 42.091 N, 74.870 W
March 31 41.652 N, 74.715 W
April 1 42.139 N, 74.780 W
April 5 41.626 N, 74.717 W
April 9 41.389 N, 74.645 W
April 11 42.458 N, 74.482 W
April 15 44.774 N, 74.063 W
1994 Eagle
Date Latitude/Longitude
Feb. 28 44.333 N, 75.983 W
March 1 44.300 N, 76.001 W
March 3 44.350 N, 75.967 W
March 7 45.183 N, 76.450 W
March 10 45.150 N, 76.466 W
March 11 45.216 N, 76.433 W
March 13 45.350 N, 76.466 W
March 15 45.516 N, 76.450 W
March 17 46.250 N, 75.883 W
March 19 46.350 N, 75.766 W
March 22 46.266 N, 75.966 W
March 23 46.300 N, 76.000 W
March 25 46.300 N, 75.900 W
March 27 46.350 N, 75.866 W
March 29 46.516 N, 76.033 W
March 31 48.450 N, 74.966 W
April 2 48.383 N, 74.933 W
April 5 48.400 N, 75.133 W
April 6 48.366 N, 75.033 W
April 8 48.316 N, 75.000 W
April 10 48.316 N, 75.200 W
1995 Eagle
Date Latitude/Longitude
March 1 41.234 N, 75.186 W
March 17 41.558 N, 75.122 W
March 20 42.041 N, 74.925 W
March 27 43.731 N, 73.072 W
March 31 44.969 N, 72 268 W
April 2 46.033 N, 71.532 W
April 6 46.758 N, 70.294 W
April 8 48.258 N, 70.028 W
April 10 48.981 N, 68.798 W
April 14 49.280 N, 68.386 W
How to Respond to Challenge Question # 82
1. Address an e-mail message to: jn-challenge@learner.org
2. In the Subject Line of the message write: Challenge Question #82.
3. In the body of the message, give your school's name and location and answer this question:
"When did each of our 3 eagles begin its migration? If the dates are different, what do you think this could mean? "
The Next Bald Eagle Migration Update Will be Posted on April 22, 1996.
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