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Journey North News will be posted onThursdays Feb. 26, Mar.12, 26, Apr. 9, 23 May 7
Common Loon Migration Update: March 12, 1998
Here's the latest news from our loon Biologists in California and Florida that suggests the loons are in the early stages of attaining their breeding plumage, readying themselves for migration! After reading their Field Reports, see if you are "ready" to answer the Challenge Question that follows their reports.
Field Report From Loon Wintering Grounds in California To: Journey North From: Lucy S.Vliestra March 10, 1998 "Common Loons are still not showing many signs of migration. Most are still in full winter plumage, although some are starting to show hints of breeding plumage including black faces and white-spotted backs. Red-throated loons and Pacific loons are really changing plumage now and nearly half of all red-throated loons that I see are in full breeding attire. I am also seeing larger and larger groups of Pacific loons lately, potentially pre-migratory aggregations that have been described by local birding authorities." "Gray whale movements through Monterey Bay have slowed over the past couple of weeks. Residents say this period is usually quiet for whales as we await the first major movement of subadult whales in late March." Lucy S. Vlietstra, Monterey Bay, California Field Report From Loon Wintering Grounds in Florida To: Journey North From: Joe Kaplan and Keren Tischler March 9, 1998
Are You Ready For Their Arrival and Challenge Question # 3 ?
You'll need a Field Guide to North American Birds. Although they're called Common
Loons, they are not commonly seen by most people. At first glance, many birds may
appear the same. Look more closely and read the information carefully. To identify
a bird correctly you must consider such things as its: size, shape, colors, markings,
vocalization, the bird's location and even its behavior! Now, look closely at the face of the loon pictured here, consider the Field Reports above, and see if you can answer:
(To respond to this Challenge Question, please follow the instructions at the end of this report.)
How to Track Loon Migration
If loons over-winter in your region, please report your "FIRST" loon NOW. We'll know by the date that your sighting was pre-migration. (Since our computer can't add an extra category for "over-wintering" sightings, we ask that you report these as "FIRST" sightings.)
Scientists Discuss Challenge Question # 1
In our last report, we asked: "If feathers can be collected from loons at
different stages of maturity, what do you think they might help the biologist to
understand?" Challenge Question # 4
(To respond to this Challenge Question, please follow the instructions at the end of this report.)
Journey North Observer Concerned about Beached Loons in Florida To: Journey North From: Francis Harvey "I am from Canada, visiting Panama City Beach, Florida. Each day, I walk the beach and for the past three weeks I have marvelled at the common loons playing in the surf. Now, during the past five days, there are no loons in the surf - just dead loons on the beach. Why?? What is killing them?? Yesterday, there were two dead loons on Panama City Beach. On Monday, there were 3 dead loons, and last week there was one dead loon. I have reported this to the Panama City News Herald and to Channel 7 News." "My concern is that when I go home to Canada and go fishing in the summer, I may not hear these magnificent creatures yodelling across the Rideau Lakes where there are about 14 or 15 nesting pairs each summer. I like loons. Why are they dying on Panama City Beach??" Smiths Falls, ON, Canada K7A4S4 alice@panacom.com We forwarded this note to biologist Dave Evers. Here are his comments: "I'll talk to Joe and Keren about this and see if they can get up there soon. They're at the Ding Darling NWR and are slowly making their way into the panhandle of FL. That area is where there was an estimated 2,500 to 10,000 loons that died in the winter of 1982-83. That die-off was strongly linked with mercury." "It's hard to say right now why loons are dying there, but there is also a dieoff going on off the coast of NC per Stephanie of the Outer Banks Wildlife Shelter. Maybe you can get some sort of network going and we can find out how many loons are being found on beaches around the country." "There are several studies that have shown the period of molt to be very stressful and energy consuming for birds. Loons are flightless for about 2-3 weeks while their new feathers develop. This is the time when loons are in greatest danger. Not only are they unable to fly, but they must expend significant energy to grow feathers. (There are 11 primary feathers and 22-23 secondary feathers on each wing-- that's a lot of feathers and they're big!) Since they are using their energy stores they are less able to deal with diseases at this time. When the molt is finished, they have brand new feathers for their trip north." "Loons may especially be vulnerable due to the synchronous remigial molt (i.e., all the flight feathers are growing in at once). The 1982-83 dieoff occurred during wing molt of the local population. There may be a link to mercury. Methylmercury is bound up in the muscle tissue of loons, particularly those individuals that have accumulated a lot of it during the breeding season. During stressful times, like a wing molt, a lot of energy is needed to grow in the new feathers and methylmercury can be remobilized from the muscle tissue into the blood and subject the loon (i.e., its brain) to high levels of mercury." How to Respond to Journey North Loon Challenge Questions: Please answer ONLY ONE question in each e-mail message: 1. Address an e-mail message to: jn-challenge-loon@learner.org 2. In the Subject Line of your message write: Challenge Question # 3 (OR # 4) 3. In the body of the EACH message, give your answer the questions above. The Next Loon Migration Update will Be Posted on March 26, 1998. Copyright 1998 Journey North. All Rights Reserved. |