From National Geographic
Most people have seen birds cruising on air currents, whether they be hawks, eagles, vultures, or crows, but few can imagine a bird the size of a small airplane gliding over the world’s highways and byways. Long before Big Bird began roaming Sesame St.¹ Argentavis magnificens did just that.
A colossal bird, Argentavis magnificens soared over parts of Argentina approximately six million years ago. It boasted a twenty-one foot wingspan and weighed an estimated one-hundred and fifty-five pounds. In comparison, the longest wingspan of a living bird is that of the wandering albatross (Diomedea exulans) measuring in at a measly ten feet, while the heaviest flying bird, the kori bustard (Ardeotis kori) weighs only about forty pounds.
Argentavis’ great weight made for an ungainly take-off. Using computer simulations originally designed for helicopters, researchers have come to the conclusion that Argentavis could probably get airborne only by running downhill, or launching itself from a high point. However, once aloft, Argentavis used its massive wings to soar with the best of them. It is estimated to have been able to cover distances of up to two-hundred miles at a speed of just over forty miles per hour, with a diving speed of up to one-hundred and fifty miles per hour.
While Argentavis could by no means carry off lift an elephant into the air like the mythical roc it was likely a capable predator. Its head measured twenty inches and sported an impressive hawklike bill. Coupled with its impressive diving speed and fierce talons, Argentavis could take down large prey with ease.
from Birdfinders
Much less capable of catching large prey, but equally impressive in its own way is Cuba’s zunzuncito, or bee hummingbird, the world’s smallest bird. The bee hummingbird (Mellisuga helenae) has a length of approximately two inches and weighs around .0635 ounces, with males being slightly smaller than females. It would take approximately 39,060 bee hummingbirds to equal the weight of one Argentavis magnificens. Not satisfied to be the smallest bird, the bee hummingbird is the smallest warm-blooded vertebrate.²
Unlike Argentavis, the bee hummingbird has no trouble taking off. With wing muscles that make up 22 to 34 percent of their body weight, they can fly at a speed of up to 30 miles per hour. Like other hummingbird they are adept at various aerial feats like hovering, vertical and backwards flight, and are even able to fly upside down.
These little birds feed primarily on nectar and small insects. Don’t be fooled by their humble diet, though; bee hummingbirds are as tough as they come. Males will establish feeding zones from which they aggressively chase all competitors be they other males, bumblebees, or hawk moths.
The bee hummingbird is also able to conserve energy during cool nights by dropping their body temperature. During the day their temperature is about 106 degrees Fahrenheit, but can drop down as low as 86 degrees in a sort of mini-hibernation.
Sadly, the bee hummingbird may go the way of Argentavis magnificens. While it is only considered Near Threatened by the International Union for the Conservation of Nature, its fairly small population is declining meaning its situation may worsen.
—
1. Big Bird has been roaming Sesame St. since 1969, played always by Carroll Spinney.
2. The honor of smallest vertebrate currently goes to Paedocypris progenetica, a tiny fish that lives in highly acidic swamps on the island of Sumatra. This little fish is only 7.9mm long, less than 1/3 an inch. It also sports a skull that leaves its brain unprotected by bone. Unfortunately, Paedocypris progenetica faces danger due to habitat damage caused by forest fire, logging, agriculture, and urbanization.
For more on this delightful relative of the carp:
http://www.nhm.ac.uk/about-us/news/2006/jan/news_7501.html
http://www.guardian.co.uk/world/2006/jan/25/indonesia.science
More about Argentavis magnificens:
http://www.cosmosmagazine.com/node/1421
http://www.telegraph.co.uk/scienceandtechnology/science/sciencenews/3299302/How-the-dinosaur-bird-took-to-the-skies.html
http://news.nationalgeographic.com/news/2007/07/070702-biggest-bird.html
http://www.npr.org/templates/story/story.php?storyId=11710794
http://news.bbc.co.uk/2/hi/science/nature/6262740.stm
http://www.pnas.org/content/104/30/12398.abstract
More about the bee hummingbird:
http://animaldiversity.ummz.umich.edu/site/accounts/information/Mellisuga_helenae.html
http://www.birdlife.org/datazone/species/index.html?action=SpcHTMDetails.asp&sid=2101&m=0
