Sunday, January 29, 2012

Hummingbird Notes

The Princeton Environmental Film Festival is concentrated this year into three 4-day weekends, of which this is the first. Saturday afternoon included a showing of "Hummingbirds: Magic in the Air", which uses cameras with 500 frames per second to show their singular hovering skills in slow motion. After the movie came a fascinating lecture by Charles Leck, a retired Rutgers professor. Here are some notes:

  • New Jersey's Ruby-Throated hummingbirds enter NJ each spring at the southern tip, returning from winter habitat in Central America. They migrate across the Gulf, flying about 8 feet above the water at 50 mph. Charles described sitting on the beach at the right time of year, watching as they'd come flying in off the ocean at the rate of about one every couple minutes. 
  • For the 500 mile non-stop flight across the water, they first build up their body weight, then may lose a third of it during the flight. They store nectar in their bodies as a fat that, when metabolized for energy, becomes water that in turn keeps them sufficiently hydrated during the flight.
  • During the day they maintain a body temperature around 105 degrees. Any higher and proteins would start to denature. At night, they ramp their supercharged metabolism down to 55 degrees. (The movie shows this transformation by using infrared cameras that register heat as read and coolness as blue.)
  • Charles mentioned the marsh at Rogers Refuge in Princeton as the best place to see the male hummingbird mating flight, on May 7 or 8. Stop by on those dates and there will likely be other birders to show you where to look.
  • Since hummingbirds cannot live on nectar alone, they have to catch insects with their skinny beaks to get protein.  Sometimes it's easier for them to rob spider webs.
  • The Lecks often lead walks sponsored by Washington Crossing Audubon or the Trenton Marsh.
There's much more information at hummingbirds.net.



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