28 March 2009

Zoo Birds

While Dana, Tony, Justin, and I worked in the herbarium at the Missouri Botanical Garden a few weeks ago, Lindsay spent a day with her friend Jenny and Jenny's daughter Allison at the St. Louis Zoo. Lindsay captured some pretty nice photos, so I wanted to share some information on some of the birds she saw.

Savannas in Sub-Saharan Africa are the natural haunts of the Bateleur Eagle (Terathopius ecaudatus). The genus name Terathopius means "marvelous face," which you can see in the photograph above. The specific epithet means "without tail," a reference to the very short tail on this medium-sized eagle. Bateleur eagles are aerial acrobats that characteristically tip their wings back and forth when they are flying, reminiscent of a tightrope act; in fact, "Bateleur" is French for "tightrope walker." These snake eagles mate for life, staying in the same nest for many years, and the female lays just a single egg. Only ~2% of chicks survive to become adults, which takes 7 or 8 years. Bateleur Eagles feed mostly on birds, but also will eat snakes, some mammals, and carrion.

The Blue Crane (Anthropoides paradisea) is endemic to southern Africa; greater than 99% of the populations of this species occur in South Africa, with a small population also occurring in neighboring Namibia, and breeding pairs found in 5 other countries on occasion. Unfortunately, this critically endangered species is in decline as a result of population growth, afforestation, and poisoning, both intentional to protect crops and unintentional as a result of pesticide application. The National Bird of South Africa, Blue Cranes are ~4 feet tall and can be found feeding on insects, small vertibrates, and plant seeds in dry grasslands.

Puffins are a group of pelagic seabirds that Lindsay and I have never seen in the wild. One of the four living species in the genus Fratercula, Latin for "little brother" (so named as a reference to the black and white plumage which resembles monastic robes), is the Tufted Puffin (Fratercula cirrhata) (cirrhata is Latin for "tufted"). Tufted Puffins can be found throughout the North Pacific Ocean feeding on fish, squid, crustaceans, mollusks, and other invertebrates. One of the first things you'll notice in looking at this bird is the huge bill, which is used by adult Tufted Puffins to store prey as they bring a meal back to their young (they've been known to carry up to 60 fish at one time!). Adults of this species also likely mate for life, and the female produces just a single egg.

Get a load of that prehistoric-looking thing! This is a Great Hornbill (Buceros bicornis), a species found in India, the Malay Peninsula, and Indonesia, known to live for up to 50 years! The "horn" on the top of the bill, known as a "casque," is a sign of sexual maturity in this species; it begins to form on juveniles that are 6 months old, but takes 5 years to fully form. The casque acts as a resonating chamber to amplify the nasal sounds produced by this unique forest bird. Great Hornbills feed mostly on fruit, but can also be seen eating small mammals, birds, snakes, lizards, and large insects. Another species that mates for life, Great Hornbills produce one or two eggs per clutch (though usually only one chick hatches) in hollowed out trees. Once the eggs are produced, the male leaves the female and eggs in the hollow tree, and the two nearly completely enclose the female and eggs in the tree using feces and food. The female then spends the next four months in the tree with the eggs, until the chick has hatched and is nearly ready to leave the nest. The male hornbill feeds the female through a small slit in the enclosed cavity during this time. About a week before the chick is ready to leave the nest, the female breaks through the enclosure to help the male find food, and the chick immediately rebuilds the barrier to protect it from predators! Unfortunately, populations of this amazing species are also in decline.

There are 16 living species of macaws in the world. The largest of those is the Hyacinth Macaw (Anodorhynchos hyacinthinus), a species native to central and eastern South America that lives in palm swamps, woodlands, and other semi-open wooded areas, avoiding heavily forested areas. Hyacinth Macaws feed on various nuts, seeds, and fruits; they particularly pine and palm nuts. Like the Scarlet Macaws that Lindsay posted about here, Hyacinth Macaws mate for life. Nesting occurs in existing holes in trees, where the female produces one or two eggs. If two eggs are produced, only one hatchling will survive, as the second born and smaller fledgling is not able to compete with the larger fledgling for food. Hyacinth Macaws are considered a threatened species, a result of their popularity in the pet trade as well as loss of appropriate habitat. Their numbers have seen a 50% reduction in the past 10 years or 3 generations, and another 50% reduction is expected in the next 10 years or 3 generations. These gorgeous birds are definitely in danger of becoming extinct.

The Spectacled Owl (Pulsatrix perspicillata) ranges from southern Mexico through Central America and the northern 2/3 of South America, where it can be found in mature tropical rainforests, dry forests, treed savannas, plantations, and open areas with scattered trees. Like many other owls, this is a nocturnal species. Spectacled Owls feed on mammals, crabs, frogs, and large insects; they will even eat birds and other owls. Females produce 1 or 2 eggs, but generally only one fledgling survives. The young bird depends on its parents for about a year after fledging.

The White Stork (Ciconia ciconia) is an approximately 4 foot tall wading bird found in parts of Europe, northwest Africa, and southwest Asia. They migrate and winter in tropical Africa to South Africa, as well as in India. White Storks breed in open farmland with access to marshes; nesting occurs in trees, on buildings, or on nesting platforms. They feed on frogs, large insects, small birds, lizards, and rodents.

And then, there are the penguins. Seventeen species of penguins exist worldwide; unforturnately, populations of most of these are declining. Lindsay watched a program on PBS last week about this goofy group of birds. From the program, Lindsay learned that penguins can survive and breed in areas that are often too cold for plant life. They usually are found in large colonies. Penguins can't fly, and are very clumsy on land, but they are agile divers and swimmers, using their wings as flippers. Their biggest enemy, aside from global climate change, seems to be seals and sea lions.

Did you know there were penguins in Africa? I certainly didn't. The African Penguin (Spheniscus demersus) is found naturally on islands along the southwestern coast of Africa, as well as in a few mainland locations in Africa; this is the only species of penguin that breeds in Africa. Another monogomous bird species, the male and female take turns incubating and feeding their young. African Penguins feed on fish, small crustaceans, and squid. Unfortunately, African Penguins were nearly driven to extinction as a result of harvesting of eggs and guano (they nest in excavations within sun-hardened guano), feral cats, and oil pollution; less than 10% of the orignal populations remain. As stated above, they are excellent swimmers, reaching top speeds of approximately 12.5 mph and staying under water for up to 2 minutes.

Gentoo Penguins (Pygoscelis papua) are found on Antarctica and on sub-Antarctic islands, giving them the greatest distribution of any penguin species. They feed mostly on crustaceans, but will also eat fish and squid. Their nests often consist of a pile of stones, but sometimes consist of grasses and other vegetation. Females typically produce 2 eggs, and the parents take turns incubating the eggs. Both hatchlings usually develop; however, if food is scarce, the parents will feed only the stronger hatchling, letting the weaker starve to death.

You should recognize the penguin in the foreground as a Gentoo Penguin; the two in the background are King Penguins (Aptenodytes patagonicus). Becoming as large as 3 feet tall, the King Penguin ranks second in size of penguins only the the Emperor Penguin (Aptenodytes forsteri). King Penguins, which breed on sub-Antarctic islands, feed mostly on fish and squid. They have four layers of feathers, the outer of which is oily and waterproof; the three inner layers are down feathers. Chicks do not have the outer layer of feathers when born, so they cannot fish until they reach maturity. Adults can dive to depths of 1000 feet and can stay submerged for up to 15 minutes, swimming at speeds of up to 6 mph. As in the other species of penguins discussed above, the male and female alternate incubating and foraging activities. The population numbers of this majestic species are actually increasing.

Rockhopper Penguins (Eudyptes chrysocome) were given their common name as a result of the way that they hop from rock to rock in their sub-Antarctic habitat. While this species is smaller than most other penguins, Rockhopper Penguins seem to have a Napoleon complex and are very aggressive. Rockhoppers feed primarily on fish, crustaceans, and squid. Females produce two eggs, but the first is often lost or does not hatch; if it does hatch, the hatchling often does not survive. As in the other species of penguins, the parents take turns incubating and foraging/feeding.

Although all of these species were observed in a zoo setting, it is still interesting to learn about the diversity that exists throughout the avian world. It would be amazing to see these species in their natural settings, but for many of us, seeing them in captivity will probably be the best chance we get. I hope you found this post as interesting to read as I found it to write.

1 comment:

Muhammad said...

This is such an informative post. You have a lot of really great points. I wish I had this post as a resource when I started blogging.
Bird watching binoculars.