January 18, 2007
Mid-winter Eagle Survey
We continue to be optimistic about our eagle pair possibly laying one to three eggs within the next two to three weeks. The latest promising signs have included the female lying in the nest for long periods during the day. But our best indication that an egg is coming will be seeing the female spending the night on the nest. In the past two seasons, when the female spent her first full night on the nest, we had an egg the next morning, so the female's behavior will be our best indicator that an egg might be coming.
After the female lays the first egg (assuming she does), she will possibly lay one or two more eggs, and those will come about two to three days apart. The first chick will have the advantage, as it will hatch first (after about 35 days of incubation) and be bigger than its siblings. Often there is sibling rivalry in bald eagle nests, and if food is in short supply, the rivalry can be deadly. In the past two Eagle Cam seasons -- when we had three eaglets in 2005 and two eaglets in 2006 -- we did see sibling rivalry, but we never saw any acts that threatened the life of a chick, and all five chicks went on to fledge successfully. The most likely reasons for the success of all our cam eaglets were the experience of the parents and the bountiful food supply at the Refuge.
Eagle Survey
We recently received the results of our 2007 Mid-winter Eagle Survey. Mid-winter eagle surveys are held annually in many areas of the country and are used to gage the health of local eagle populations. Below are the results:
Non-Roost Count AM
Bald Eagles
Immature: 36
Mature: 61
Golden Eagles:
Mature: 1
Immature: 1
Unknown: 17
Total: 116
Top spot was Wildlife Drive again with 19 eagles.
Golden eagles were sighted at Little Blackwater River Bridge and Kuehnle North
Roost Count PM
Bald Eagles
Immature: 25
Mature: 51
Golden Eagles: 0
Unknown: 16
Total: 92
Top spot was Rte 335 Bridge again, with 23 eagles.
Both Non-roost count and Roost count numbers were slightly lower this year, and that is likely due to the mild winter we experienced at the end of 2006.
If the winter is mild, the eagles might not migrate or might have a wider range of locales where they can find food. Up until the recent cold snap, the mild winter in the U.S. had been affecting eagle migration in different areas around the country, with the midwest reporting that eagles had spread out over a larger area and were not concentrating as much around dams and other open-water magnets like they normally do at this time of year. However, now that the winter is finally turning colder, some of these eagles may need to relocate.
I also wanted to mention the golden eagles that were sighted during our survey. Golden eagles are hard to find in the eastern section of the U.S., so spotting one is a very big deal for a birder, and spotting an immature golden eagle is especially exciting. The beautiful golden eagle is one of the largest birds of prey in North America -- only trailing the bald eagle and the California condor in size.
You can read more about golden eagles at All About Birds and at ENature.
White Pine Update
One of our cam watchers sent me a link to a bald eagle page made by the Stratford Landing Elementary School that mentioned a possible explanation as to why eagles like to put white pine sprays on the top of their nests. According to the site: "Scientists think the reason eagles put sprigs of trees in their nests, is because the odor helps keep away parasites, such as blow flies. Eastern White Pine sprigs seem to be the eagles' top choice. Parasites could weaken, or even kill, a young eagle." We're not sure what the source of that information is, but it's an interesting idea.
Washington Post
Finally, I wanted to mention that the Washington Post has just published a very nice article about eagle watching at Blackwater Refuge. You can see the article here (note that you might have to register to view it). The article describes Blackwater Refuge as one of the best places to watch eagles on the East Coast, and that is something everyone at the Refuge is proud of -- especially since we can appreciate the excitement a person experiences when they see their first bald eagle in person.
In the popular John Denver song titled The Eagle and the Hawk there is a stanza that I like because it captures the magic of watching an eagle:
I am the eagle, I live in high country
In rocky cathedrals that reach to the sky
I am the hawk and there's blood on my feathers
But time is still turning they soon will be dry
And all those who see me and all who believe in me
Share in the freedom I feel when I fly
May we always have eagles to inspire and excite us.
Until next time,
Lisa - webmaster
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