I found a beautiful book about sloths which I gave to each of my grandchildren for Christmas, and even kept one for myself because the illustrations are so charming. The book is mostly photos of sloths with some text that tells a bit about them. Sloths are native to South and Central America, where they spend most of their lives hanging in trees. Their long arms and impressive hooked claws allow them to hook on and hang from branches without using much energy. In Costa Rica there is a sloth sanctuary, the first in the world, devoted to caring for orphaned and injured sloths. In the words of Lucy Cooke who wrote "A Little Book of Sloth" the reader is encouraged to "take a break from the hectic world around you, kick back, relax, and enjoy hanging with the sloths."

Sloths belong to a special group called Xenarthrans, which means they can’t control their body temperatures like other mammals. They must bask in the morning sun to warm up, like reptiles do, and they cling to their mothers for the first year of their lives. In the sanctuary the babies have stuffed toys to cling to in place of their mothers, and the photos of them with their toy friends are adorable beyond belief. Wild sloths are solitary but the sanctuary sloths make friends with each other for life.

Other interesting things about sloths—three fingered sloths are the only mammal on earth with extra neck vertebrae which enable them to turn their heads up to 270 degrees. So even when they are upside down their permanent smiles are the right way up. Wild sloths are actually green because their coats are covered with algae and insects, including a moth that lives only on sloths. These invisible cloaks save them from hunting eagles, which is good because they can’t move fast enough to escape an eagle looking for a meal, since their top speed is fifteen feet a minute.

Why are sloths so slothful? In the wild they eat leaves that are a bit toxic and don’t provide much energy. Their big stomachs allow them to take 4 weeks to digest one meal, and their stomach contents make up 2/3 of their body weight. If they didn’t digest their food slowly the toxicity of the leaves would give them severe indigestion. Another of the amazing things about sloth behavior is that they climb down from their treetop homes once a week to poo at the base of the tree. The sanctuary sloths have to be taught this unusual potty habit, which may take a while for them to learn.

"A Little Book of Sloth" is delightful and suitable for children from age 3 on up to elementary school. It is also great fun for adults because the photos are unbelievable cute. The author is Lucy Cooke and the publisher is Margaret K. McElderry Books.

In next week’s column I will share some information about current research on sloth hair which suggests microorganisms found on sloth hair may be the basis of new disease- fighting drugs.