- Apr 14, 2014
The next two full moons (tonight and 14 May) nicely bracket the peak of landbird migration through our area, and should afford good opportunities to “moon-watch” for nocturnal migrants. [Recall our moon-watching efforts back on 4 May 2012, and see the archives of this list serve for a flurry of discussion and results.]
Tonight there should be clear skies. And there is the added bonus of a lunar eclipse, though it will peak after midnight – a bit late for those of us who require some sleep. Any of you who do spend time looking at the lunar eclipse through a spotting scope might pay attention to whether birds are passing the face of the moon; and you can certainly spend time before the eclipse watching this phenomenon. For a bright full moon, be sure to use sunglasses and/or some kind of filter on your scope. During the height of the eclipse, it will be interesting to see if there is enough light on the moon’s disc to see birds moving past.
For those who wish, please moon-watch between 10:00 and 10:30 this evening and record the number of birds passing the face of the moon. If you can’t watch for the entire 30 minutes (ones eye do get tired!), then just record the number of minutes you watch so we can get a rate (birds per minute). Also, keep track of the direction of travel of the birds by using the moon as a clock face and recording the “time” the bird enters and exits – e.g. from 7:00 to 1:00 across the “clock” (=moon). From your location, you can use that to roughly determine the direction of travel.
If you do stay up for the eclipse, you might record the same information for that period (though the passage of visible migration is going to change through the night as migrating birds gain, then lose altitude). It might be that migrants won’t be visible across the face of the “blood moon” during the eclipse, but it’s worth a try.
As always, don’t worry about what kind of birds you’re seeing – you’ll notice differences in shape and wingbeat patterns, but it’s futile to try to make identifications with such brief views (and you can’t judge size, since apparent size is a function of flight altitude).
Feel free to post any results tomorrow.
Kimball L. Garrett
Ornithology Collections Manager
Natural History Museum of Los Angeles County
900 Exposition Blvd.
Los Angeles, CA 90007 USA