Naturespeak A naturalist's view of the world

August 20, 2008

A Priceless Little Gem: Part II

Filed under: Uncategorized — wykes @ 8:20 pm

A few days ago, I left you with the thought that the Ruby-throated Hummingbird is a priceless little bird based on its nest-building capabilities alone. I was able to show you a detailed view of a nest to prove my point. Today, I come with a dead bird in hand in order to examine the bird itself (see above). Sure, Iíd rather show you two in a bush but this gives us an opportunity to appreciate some normally un-observed features. The live bird is just too, well, lively!

The poor little birdlet before you apparently succumbed to starvation and was found lying on the ground.A Wikimedia article states that ďat any given moment (hummingbirds) are only hours away from starving.ĒNormally, you canít believe everything you read on the internet, but this statement merely reflects the fact that hummingbirds have one of the highest metabolism rates in the animal kingdom. Their tiny little hearts can beat 1,260 bpm and they need to eat up to 5 times their body weight each day just to keep up appearances. Any delay in the daily schedule caused by injury or bad weather can have swift and lethal consequences Ė as it did for this unfortunate fellow.

This is a male Ruby-throated Hummer, as indicated by his iridescent throat patch known as a gorget. These namesake feathers donít express their ruby-ness unless they are illuminated with the proper lighting. Most of the time they appear black or dark brown (see here) but when struck by a shaft of angled sunlight they glow like fiery coals (see here). The back feathers have the same type of structural color except that they are ignited into an emerald flame when given a breath of sunshine. You can see why there is no good way to describe them other than by using gemological terminology.

Apart from those colors, the long beak also commands our attention. Ruby-throats prefer red tubular flowers (such as the Trumpet Vine) for nectaring and this needlelike bill can penetrate down to the sugary reservoir at the base. They will feed on insects and tree sap during the course of their frenzied feeding, but rely on flower nectar for most of their nutritional needs.

The actual feeding is performed with a long tongue that is plunged into and out of the nectary. During the course of the visit, the bird inevitably gets dusted with pollen from the yellow anthers (see this cut-away view here) and thus performs an un-witting dating service for the Trumpet Vine.

†† Perhaps one of the most unappreciated features found on this minuscule fowl are the tiny feet (see here).These micro appendages are so small that the bird can neither walk nor hop on them (which matches them with elephants in the jumping category). They can manage a sideways twig shuffle and an over-the-wing head scratch, but thatís about it.

There are hundreds of species of hummingbirds in the New World, but only the Ruby-throat makes itís living here in the eastern United States. Our local representative is the product of over 30 million years of refinement Ė a delicate but proven design. Over all that time, the species has never been able to learn the words, but they hum along just fine.

1 Comment »

  1. Hummingbirds are so cool and it’s always sad to find a dead bird of any kind. Should you ever find an injured bird, you probably already know about the Bird Center of Washtenaw County. I used to volunteer there feeding the birds and also by bringing flowers from my garden for injured hummingbirds. I know you’re not in Washtenaw County, but maybe there’s a similar group where you live?

    Comment by Monica — September 7, 2008 @ 7:24 am

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