BIRDS OF NANTUCKET

This story goes back 40 years to when the USAF had me stationed at Westover Field in western Massachusetts. We were outside in the evening and I was excited to see a hummingbird working the petunias near the walkway into our apartment. It buzzed this way and that, sticking its long nose into the flowers.

Something just didn't ring true about this critter. The movements weren't right and anyway, it was almost dark. Then I realized yet again, the wisdom of Roger Tory Peterson. On his color plate showing the Ruby-throated Hummingbird he also showed a picture of a Sphinx Moth with a note "resembles hummingbird." This was my first experience with this hummingbird look-alike and it was quite enchanting.

You don't see many hummingbirds on Nantucket but they are around. There is even a nest in the collection at the Maria Mitchell Association that was found near Surfside in 1949. You really have to know what you're doing to find a hummingbird nest. It's only about the size of a walnut shell, made out of spider silk and lichens and often blends really well into the little branch to which it is attached. If the hummers themselves don't help you out by showing you where it is, you'll never find it.

Let me tell you a bit about these amazing creatures. You know they are tiny. There's a joke about a recipe requiring hummingbird tongues. It takes a lot of them to acquire the taste. Anyway, Ruby-throats are just over three inches long including that long bill. They don't occur in Europe, Asia, or Africa, so early explorers had a hard time understanding what they were seeing. There are over 300 species of hummers, mostly in Central and South America. The Bee Hummingbird of Cuba is the world's smallest bird, just over two inches long. Eighteen species make it into the U.S. and three have made it to Nantucket.

Hummingbirds were long viewed as impossible creatures. They burn energy at such a frantic rate that it seemed they would burn themselves out. Fortunately, the nectar they consume is almost pure energy, so they eat the right stuff. They also are able to slow down their metabolism while at rest, dropping their heartbeat and lowering their 110-degree body temperature in half, going into a state known as torpor at night or when it is cool.

Ruby-throats vary their wing-speed from 50 to 80 beats per second and yes, they do make a humming sound. They can even fly backwards. But they can't walk! Their feet

work for perching only. It's amusing to see a hummer perched on a phone wire. You can hardly notice the bird.

These amazing birds are also long distance migrants. Ruby-throats all leave the U.S., even southern Florida in the wintertime. They are trans-Gulf migrants, zooming across 600 miles of water at 60 mph, perhaps 25 feet above the water.

This info comes from fishermen out in the Gulf of Mexico seeing them fly by. During these flights they may burn off 1/3 of their body weight.

If you notice a hummingbird on Nantucket after the end of September it is undoubtedly NOT a Ruby-throat. Let a birder know if you see a late one since it will be a rare species from the western U.S. that has headed east instead of south. Nantucket has hosted both Allen's and Black-chinned Hummers. The most recent was a Blackchinned that lasted into November 2007 in 'Sconset with the help of a feeder.

This year has been a good one for Nantucket's Ruby-throats. Quite a few were seen during migration and there are two locations in and around Polpis and one near Bartlett's where they may be nesting.

Amazingly hummingbirds have been known to live more than nine years - spectacular for such a small creature that travels so far every year. Scientists use a term, site fidelity, for creatures that return to the same spot over and over again. For birds it means that after traveling halfway around the world and back they will seek out the same tree in the same backyard that they left eight months before. This explains why a yard in Polpis and one off the Old Quidnet Milk Route host these feathered gems every year. They are either the same birds or their offspring.

If you have them in your neighborhood they are interesting to watch. For such small creatures they carry an amazing amount of aggression and territoriality. One hummingbird always acts as the "warden," deciding who gets to feed and when. There are dramatic aerial dogfights with much humming and high-pitched vocalization.

If you put out a hummingbird feeder, use one part sugar to four parts water for the mixture. Our hummingbirds will be around into the month of September and will provide you with endless excitement. You may even be lucky enough to see a Sphinx Moth as well. I

George C. West creates illustrations for these articles.