Friday December 13, 2013
I just added a new profile to the Animal Encyclopedia. Please extend a warm welcome to the sun bear.
The sun bear is the smallest member of the bear family. Full grown, they are only about half the size of an American black bear. Adult sun bears grow to a maximum body length of about 4˝ feet and weigh at most about 145 pounds. Male sun bears are slightly larger than females. Sun bears are so named for the bright white or golden crescent of fur on their chest.
The range of sun bears has declined significantly during recent decades due to widespread habitat destruction and deforestation. Land is being cleared throughout Southeast Asia to make way forcoffee, rubber, and oil plam plantations. This loss of habitat has caused the sun bear to suffer a significant population decline and, as a consequence, the species is now classified as vulnerable by the IUCN.
To find out more, be sure to read the sun bear profile.
Photo © Anup Shah / Getty Images.
Wednesday December 11, 2013
It takes a lot of energy to power a hummingbird. To hover, hummingbirds must flap their wings 50 beats or more per second. To fuel these rapid wingbeats, hummingbirds require fast access to lots of energy. Hummingbirds also need to store energy to survive during the night (since they only feed during the day) as well as to power their flight during long migrations. These unique energetic demands have meant that hummingbirds have evolved inovative ways of metabolizing the food they eat.
Hummingbirds feed almost entirely on nectar—a sugar-laden liquid that is produced by plants. Nectar provides lots of energy becuase it is rich in sucrose, a sugar that consists of two simpler sugars: glucose and fructose. Most vertebrates, including humans and hummingbirds, are very good at breaking down glocose into usable energy. Glucose can be burned directly in muscle cells, where serves as a clean fuel for movement.
Fructose, on the other hand, is a different story. Most vertebrates are unable to break down fructose easily. It cannot be burned directly by muscle cells and must instead be metabolized in the liver where it is often converted to fat. But, when it comes to fructose metabolism, hummingbirds are not like other vertebrates.
New research by Dr. Kenneth Welch and graduate student Chris Chen at the University of Toronto Scarborough suggests that hummingbirds metabolize fructose in their own unique way. Instead of relying on the liver to break down fructose, hummingbirds can can take up fructose directly in their muscle cells. This means that they can use the sugars in nectar very efficiently to power not only their hovering flight, but their nighttime fasts and long migrations as well.
Chen, C. C. W., Welch, K. C. (2013), Hummingbirds can fuel expensive hovering flight completely with either exogenous glucose or fructose. Functional Ecology. doi: 10.1111/1365-2435.12202
More About Birds
Friday December 6, 2013
I just added a new profile to the Habitat Encyclopedia. Please visit the new Forest Biome profile page to find out about this unique region and its many animal inhabitants.
The forest biome includes terrestrial habitats that are dominated by trees and other woody plants. Today, forests cover about one-third of the world's land surface and are found in many different terrestrial regions around the globe. There are three general types of forests—temperate forests, tropical forests, and boreal forests. Each of these forest types differs in climate, species composition, and community structure.
To find out more, be sure to read the Forest Biome profile.
Photo © Raimund Linke / Getty Images.
Wednesday December 4, 2013
In 1999, conservationists set aside 4,000 acres of cloud forest on the western slopes of the Andes in southern Ecuador to protect several rare endemic species. Now, that reserve—the Buenaventura Reserve—is set to expand by another 600 acres thanks to a recent land acquisition organized by Ecuador's Fundación Jocotoco, Rainforest Trust, and American Bird Conservancy.
The Buenaventura Reserve protects 15 globally endangered bird species. Among them is the endangered El Oro parakeet, a species of parrot that was discovered in 1980 when a team of ornithologists came across the green-plumed parrot while exploring the remote cloud forests of Ecuador.
The El Oro parakeet's range is small and under threat. The species inhabits the tropical cloud forests that grow on the western slopes of the Andes between 2,600 and 4,000 feet in elevation. Its habitat is being fragmented and destroyed as land is cleared for agriculture or by logging activity. The Buenaventura Reserve protects some of the El Oro parakeet's habitat and expanding its boundaries increases the protection the rare parrot will receive.
The El Oro parakeet is not the only bird that will be protected in Buenaventura. There are more than 330 species of birds that have been identified in the reserve, 34 of which are endemic to the area. Among the birds that call Buenaventura home are cloud forest pygmy owls, grey-backed hawks, rufous-headed antbirds, grey-breasted flycatchers, and long-wattled umbrellabirds. Many migratory birds also use the Buenaventura Reserve during part of the year including Swainson's hawks, olive-sided flycatchers, black-and-white warblers, and summer tanagers.
Photo courtesy American Bird Conservancy.
More About Birds