Showing posts with label Migration. Show all posts
Showing posts with label Migration. Show all posts

Sunday, February 24, 2008

Migration Underway: Cedar Waxwing

In our last post, a migrating flock of robin visited the Colvin Run Habitat and brought with them the bird perched on the water pump tub (middle of the photo, back to the camera). Who is this? This perviously never observed in the Habitat bird is a cedar waxwing.
This regal looking bird is the size of robin, but is usually one of the last birds migrating north as they eat berries and fruit, which certainly are not available in Viriginia in late February or even early March. My guess is that this particular waxwing was wintering with other birds including these robins. When the robins came north, this waxwing just came along.
As you can see from this third photo, the coloring and the crown of the waxwing, especially when perched in the trees, is very similar to the female cardinal. Once you notice the yellow-tiped tail and the orange (nearly red)-tiped wings, you'll never confuse the waxwing with the femal cardinal.

Cedar waxwings with orange instead of yellow tail tips began appearing in the northeastern United States and southeastern Canada beginning in the 1960s. The orange color is the result of a red pigment picked up from the berries of an introduced species of honeysuckle. If a waxwing eats the berries while it is growing a tail feather, the tip of the feather will be orange.
The cedar waxwing is one of the few temperate dwelling birds that specializes in eating fruit. It can survive on fruit alone for several months. Unlike many birds that regurgitate seeds from fruit they eat, the cedar waxwing defecates fruit seeds. The cedar waxwing is vulnerable to alcohol intoxication and death after eating fermented fruit. Cornell


Saturday, February 23, 2008

Migration Underway: American Robin

Last Sunday at about 3 in the afternoon as I was completing my work for the Great Backyard Bird Count, I noticed a single robin perched in the oak tree among a number of male and female cardinals.
Then, another robin appeared in the dogwood and still another appeared in the Bradford pear tree. Within a minute, there were two dozen robins in the Habitat. Clearly, a migrating flock of robins had picked the Habitat as a stop over on their way north.
They quickly found and enjoyed the water available in the tub and the flower pots. The robins mingled with the other birds and were still in the Habitat when the sun went down. I did not see them the next morning. I have not seen them since. In this 2 hour period, I saw more robins in the Habitat than will be observed throughout the spring and summer months.
Take a close look at this last photo. Notice a bird other than a robin? Who is this previously unobserved-in-the-Habitat visitor? Stay tuned. We'll talk about this fellow in our next posting.





Friday, February 22, 2008

Migration Underway: Yellow-Bellied Sapsucker

This week in 2007, I observed for the first time a yellow-bellied sapsucker. Yes, the yellow-bellied sapsucker is real and not a fictional bird. Since that time in 2007, the yellow-bellied sapsucker has not been seen. Until this morning.
This morning, two yellow-bellied sapsuckers - a male and female (chin and throat red in male, white in female). They were both on the same maple tree. In fact, it was only when I looked closely at the photos that I realized these were two different birds.
Given the timing of these two observations and limited observations, it is clear that these are migrating woodpeckers. The yellow-bellied sapsucker is the only woodpecker in eastern North America that is completely migratory. [Cornell] That is, their summer and winter regions do not over lap; or, they do not stay in one region year around.
After some additional study, two other observations. First, it is clear that the yellow-bellied sapsucker has been in the Colvin Run Habitat for the last week or so based on the song provided at [Cornell]. Second, shown in the last photo are deep round holes that the sapsucker inserts its bill into to probe for sap and rectangular holes which are shallower. New holes usually are made in a line with old holes, or in a new line above the old.