Reindeer Baby Boris Grows Up
See Kim’s previous post, Reindeer Baby Boris Comes Home.
As Boris grew older, physical changes in him became more and more obvious. He was getting taller and more muscular. His thick velvet coat was getting even more dense, and antler buds were beginning to grow on top of his fuzzy black head. Every once in awhile Boris would delicately balance on three legs in order to scratch an antler bud with his hoof, as if satisfying a little itch. He also began growing the thick patch of skin and hair that reindeer display under their throats. Boris was beginning to look more like a reindeer and less like a Holstein calf!
Interestingly, reindeer and caribou are the only species of deer in which males, females, and even calves produce antlers (see post All about Antlers). Female reindeer and calves shed their antlers around March or April and start growing new antlers immediately after shedding the old ones. Male reindeer shed their antlers at the end of the winter season, after the rut, and grow them again around January or February. Inside the fur-covered nose of a reindeer are long nasal passages that warm the cold winter air before it reaches the animal’s lungs. A furry scarf or “dewlap” of skin and hair worn under their throats is really an inflatable pouch of skin that amplifies the roaring sound made during rutting season. Other vocalizations reindeer make are honks and bellows. We have heard Boris honk when he is waiting for a bottle and bellow when it isn’t coming quickly enough! Reindeer calves are born with teeth, and when they are just a few weeks old they begin sampling the solid food their mothers eat. In the wild tundra, reindeer dine on the leaves and branches of willows and graze on grasses and sedges. In the winter they use their well-adapted hooves to dig under the snow and ice to reach their favorite food of lichens, sometimes called “reindeer moss.”
When Boris was about one week old, he began sampling the solid food that was set aside for him by his keepers. He favored the leaves from the acacia branches hung for him to sample and began picking up strands of hay to taste as well. Although most of it dribbled out of his mouth and onto the ground at first, he eventually learned to chew and swallow a bit of both. Mimicking the adult reindeer, he got better at it and was soon munching his hay and pellet like a pro. Thanks to a very healthy appetite, Boris was gaining about 5 pounds (2 kilograms) a week! He was quickly out-growing his howdy pen and was ready to graduate to the large exhibit. Kim Weibel is a senior keeper at the San Diego Zoo. Check back soon for Kim’s next post about Boris.