While the exact number is debatable, there are between 325 and 340 hummingbird species. Globally restricted to the Americas, Ecuador is the king of hummingbird diversity with its 132 confirmed varieties. At 5 cm and the mass of a U.S. penny, the Cuban bee hummingbird (Mellisuga helenae) is the smallest avian species alive today. Although little, hummingbirds are not inconspicuous animals. Males fearlessly flash iridescent colors around the neck in what is known as the gorget display. Revealing bright hues of red, green and blue, such displays are aggressive messages that denote breeding and feeding territories. Despite their diminutive size, hummingbirds will dive-bomb conspecifics as well as invading species that compete for their food and space. Survival for a hummingbird is all about energy conservation. With wingbeats of 50 beats per second during a hover and 200 beats per second on an attack, these birds drain their fuel like a HUMMER H2 climbing a steep hill. Daytime heart rates can exceed 1000 beats per minute in order to sustain the high oxygen and nutrient demands of wing muscles. This intense activity requires an energy rich diet, which explains why the typical hummingbird needs to consume a greater nectar mass per day than its own body mass. At night hummingbirds “shut down.” Referred to as torpor, the body enters a hypothermic state as it drops nearly 20o C and the heart rate falls to between 50 and 180 beats per minute. Even with these energy saving measures, hummingbirds still lose 10% of their total body weight each night. Underscoring these high energy demands is the fact that some species like the ruby-throated hummingbird (Archilochus colubris) will migrate from Central America to northern Ontario, Canada.
©2000-2015 BTLeventhal.com / Bruce & Tamy Leventhal. All rights reserved. No image on this site may be used without permission.