The first two reports of migrating loons arrived this week. A single bird was observed by Dr. David L. Hanselman (dlhansel@mailbox.syr.edu) on March 15th. It was seen on Lake Charleston near Outlet, Ontario. Most of the lake was iced over but the loon was in an area of open water. A second loon was reported to Dave Evers from a colleague in southern Michigan. We'll try to get more specific location in our next report.
With the migration underway we hope you're ready to report the first loon you see this spring. Be sure to include the name of the lake or pond where the loon was sighted and, if you know it, its ice-out date. Please be sure to include the name of the nearest town, so we can find the location on a map. Send your report to: jn- report@learner.org
Research Update:
Preparations for Tracking Loon Migration by Satellite Telemetry
Last week we asked, "Why do you think it was important for Pete to gather 30 minute behavioral observations from 40 different loons?" As you'll read later in this report, students' answers were right on!
Dave Evers has good news and bad news to report about his research this week. Here's an update:
Pete Reaman released the loon last week as planned. He followed its movements for 6 days using radio telemetry, watching carefully for signs of unusual behavior. During that time, the loon did not appear to be bothered by the antenna in any way. Its foraging and preening behaviors were completely normal. The results were better than expected and the scientists were encouraged. However, as you recall from our last report, the loon was originally captured because it came onshore and even allowed people to pick it up. The loon came ashore repeatedly over the past week-- until finally it was killed by a raccoon during the night!
Here are Dave's comments:
"Loons only come to shore for 3 things, mating, incubation, and if they're sick/dead. Healthy loons have no other reason for being near shore, as it is a very risky place to be. For unknown reasons, this loon was sitting on shore and allowing people to pick it up. I have some thoughts on why.
"We're concerned because we're finding more and more loons behaving in this way. There are several cases this past year. We're afraid that it could be a hormonal imbalance due to 'endocrine-disrupting' chemicals in the body. The name 'endocrine disrupters' refers to chemicals that interfere with the normal balance of hormones. This is a new topic in conservation and some people think these chemicals may be as harmful as DDT. Clearly research is needed in this area because there are thousands of chemicals in our environment that have never been tested for their effects on humans or wildlife. Since loons are high in the food chain, chemicals can be highly concentrated in their food. The health of loons can serve as an indicator of the health of our environment.
"For more information about endocrine disrupters see the current issue of Natural History magazine. If you read the article, please try to answer Challenge Question #48:
Challenge Question # 48
"What do you know about 'endocrine disrupters'? Which animals seem to be affected by them?"
"On a positive note, Pete caught a second loon two nights ago. To attract the loon, he used nightlighting techniques and recordings of hoot and wail calls. This loon will receive the second test transmitter tomorrow morning. This is especially exciting because we feel we'll be able to capture loons with this method quite simply. We're now ready to order a satellite transmitter--and hope to be able to track spring migration this year! We must hurry because their departure from Florida is about to begin.
"We've accomplished two major hurdles this past month:
1) We determined the acceptability of a satellite transmitter shell.
2) We've learned we can capture wild, wintering loons.
More later,
Dave
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Answers to Challenge Question # 38
"Why do you think it was important for Pete to gather 30 minute behavioral observations from 40 different loons?"
From Dave Evers:
"These behavioral observations will be used as our reference condition for wild loon behavior in the winter. We will then compare the behavior of the experimental bird with our data set to see if there is an effect from the antenna."
From Pennsylvania:
"I think it was important for Pete to gather 30 minute behavioral
observations from 40 different loons so that he can compare the behavior
of the loon wearing the antenna to others who don't have one. This way he
can make sure the loon wearing an antenna is acting normal when released
back into the wild." By, Rachel Kramer nheilman@oak.kcsd.k12.pa.us
From Glennallen Junior High:
"It was important to gather information on behavior patterns from
other loons so that he could tell how normal, or abnormal, the loon
with the antenna is acting once it is released."
"That if the loon did not act like the other loons the transmitter might be bothering it. If you look at 40 different loons you will get a better idea of what the loons should act like."
Ariana Bates and Jeremy Stevens
Glennallen Junior High 7th grade jszarzi@igc.apc.org
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How to Respond to Challenge Question # 48
1. Address an e-mail message to: jn-challenge@learner.org
2. In the Subject Line of your message write: Challenge Question # 48.
3. In the Body of your message answer this question:
"What do you know about 'endocrine disrupters'? Which animals seem to be affected by them?"
The Next Common Loon Migration Update Will be Posted on March 28, 1996
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