Galápagos Tortoise

Galápagos tortoises are the giants of the tortoise world. Males can weigh more than 500 pounds (227 kilograms), and females average about 250 pounds (113 kilograms). They have thick, sturdy legs to hold up all that weight, but they still spend a lot of time lying down to conserve energy. There are two types of Galápagos tortoises. The largest, with big, round shells, are called “domes.” The smaller kinds of tortoises have shells that curl up in front like a saddle and are called “saddlebacks.” Naturalist Charles Darwin made his historic voyage on the HMS Beagle from 1831 to 1836. When the ship sailed around the Galápagos Islands, he and his shipmates marveled at the animal life they found, from blue-footed boobies and marine iguanas to giant tortoises. One thing that caught his eye was that each of the 13 larger islands in the Galápagos Islands had a slightly different form of giant tortoise. Each was uniquely suited for survival on that particular island’s environment. For example, domed shells were found on tortoises living in highlands with lush pastures. Saddleback shells gave the tortoises on other islands more flexibility to reach sparse vegetation found higher off the ground, allowing them to stretch their neck to eat from bushes and cactus. On islands with sparse vegetation, the tortoises have longer legs to climb a little and reach food growing up high; these tortoises tend to be smaller, possibly to help them travel through their harsher habitat. Galápagos tortoises are herbivores that eat prickly pear cactus (a favorite) and fruits, as well as flowers, leaves, and grasses. In fact, these tortoises can go without eating or drinking for up to a year, because they can store food and water so well. Tortoises don’t have teeth, so they use the bony outer edges of the mouth to bite off and mash food. Once in the mouth, food is quickly swallowed. They don’t have a good sense of smell, so they use their eyes to find food. Anything red really gets their attention!

Hyacinth Macaw

Many people are familiar with macaws and parrots as pet store animals. It might be difficult, then, for people to imagine what these large, loud, beautiful birds look like in the wild. The spectacular flash of color of a wild macaw is becoming more and more of a rare sight. The largest species of macaw, the brilliant-blue hyacinth grows to be up to 40 inches (1 m) long. The hyacinth macaw survives today in three known distinct populationin southern Brazil, eastern Bolivia and northeastern Paraguay. It is possible that smaller, fragmented populations occur in other areas of its range. Although it is difficult to estimate, some people believe there were more than 100,000 hyacinth macaws before the arrival of Amerindians in South America. In 1990, the wild population was estimated to be 2,500 birds. The world’s captive population is probably much larger, numbering in the thousands. The hyacinth macaw is found primarily in riverside topical rain forest and palm swamps. Its habitat varies throughout its range, however, from seasonally moist forest with a broken canopy, to mature palm forest, to grassy marshes. The hyacinth macaw nests in holes in trees. The clutch size is two or three eggs, although usually only one fledgling survives. The hyacinth macaw eats seeds, nuts, fruits, and vegetable matter. Eight species of palm are central to its diet. Its exceptionally powerful bill, the largest of its kind in the world, allows it to eat otherwise inaccessible nuts and seeds. Macaws can eat some poisonous seeds and unripe fruits that no other animal can digest. Scientists believe this is possible because the birds eat chunks of clay from river banks. The clay is thought to help absorb the poisons or make them harmless. Macaws play an important role in seed dispersal. They are messy eaters, carrying and dropping many nuts and seeds.