Interesting Creatures of Guyana: The Humming Bird

Jun 08, 2008 News

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Best known for their intriguing ability to hover in mid-air by rapidly flapping their wings 15 to 18 times per second, Humming Birds are listed among the smallest bird species which can be found mainly in the Americas, ranging from Southern Alaska to the Caribbean.

The majority of this bird species which is said to be of the family Trochilidae have been sighted in tropical Central and South America.
It is said that the name of the Humming Bird derives from the characteristic hum made by their flapping wings.
In addition to being capable of sustained hovering, these birds also have the amazing ability to fly backwards, being the only group of birds able to do so. A typical description of a Humming Bird is a bird with a long, thin bill. But what is intriguing to note is that the bill, combined with an extendable, bifurcated tongue evolves in order to allow the bird to feed upon nectar deep within flowers.
In fact, a Humming Bird’s bill can be opened wide even as the lower half (mandible) also has the ability to flex downward to create an even wider opening, facilitating the capture of flying insects in the mouth rather than at the tip of the bill.
Researchers have been able to uncover that there are between 325 and 340 species of Humming Birds, with the Bee Hummingbird (Mellisuga helenae) being arguably the smallest bird in the world. It is said that this bird weighs 1.8 grams (g) and measures about five centimetres (cm).
And then there is the average sized Rufous Humming Bird (Selasphorus rufus) which weighs approximately three grams and has a length of 10 to 12 cm.
The largest of this bird species is the Giant Humming Bird (Patagona gigas) and it is said that some can weigh as much as 24 g and measure around 21.5 cm.
However, it is said that most species exhibit conspicuous sexual dimorphism with males more brightly coloured and females displaying more cryptic colouration.
It is said that iridescent plumage is present in both sexes of most species with green in some cases being the most common colour.
Researchers have also deduced that highly modified structures within certain feathers, usually concentrated on the head and breast, produce intense metallic iridescence in a rainbow of colours.
Reports are that many plants pollinated by Humming Birds produce flowers in shades of red, orange and bright pink, though the birds will take nectar from flowers of many colours.
It is said that they feed primarily on ornithophilous flowers for nectar which is a requisite source of energy, while small insects are their source of protein.
They reportedly consume many insects and up to five times their own body weight in nectars on a daily basis and therefore must visit hundreds of plants in a day. Reports are that at any given point in time, they are just hours away from starving.
However, it is said that nectar is a poor source of nutrients, thus forcing the birds to meet their need for protein, amino acids, vitamins, and minerals by preying on insects and spiders, especially when feeding their young.
And as far as it is known to researchers, male Humming Birds do not take part in nesting.
It is said that most species make a cup-shaped nest on the branch of a tree or shrub which varies in size ranging from smaller than half of a walnut shell to several centimetres in diameter. Two white eggs are usually laid, which despite being the smallest of all bird eggs are in fact large relative to the Humming Bird’s adult size.
The incubation period is typically 12 to 19 days.
And while they are well known for their flying ability, they however do not spend all day flying. In fact, they spend most of their lives sitting, perching and watching the world.
Nonetheless, the flight of the Humming Bird has been studied intensively from an aerodynamic perspective using wind tunnels and high-speed video cameras.
According to published reports, Bio mechanist Douglas Warrick and co-workers were able to study the Rufous Humming Bird in a wind tunnel using particle image velocimetry techniques and investigated the lift generated on the bird’s up-stroke and down-stroke.
They concluded that their subjects produced 75 per cent of their weight support during the down-stroke and 25 per cent during the up-stroke.
It has also been deduced that with the exception of insects, Humming Birds while in flight have the highest metabolism of all animals, a necessity in order to support the rapid beating of their wings.
Reports are that their heart rate can reach as high as 1,260 beats per minute.
However, they are said to be capable of slowing down their metabolism at night or any other time food is not readily available.
Moreover, it is said that most organisms with very rapid metabolism have short life spans but reports are that Humming Birds have been known to survive even in captivity for as long as 17 years. (Source: Wikepedia – The Free Online Encyclopedia)

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