The Zoo

The Philadelphia Zoo joins Kids Corner monthly to explore the fascinating world found behind the gates of America's First Zoo!

Animals in the Summer

Summer is right around the corner and this time of year, everyone loves to take a swim in the pool, lounge around in the shade or even air-conditioning just to stay cool. The animals are doing the exact same thing at the Zoo!

Some like it hot!

There are a number of animals that thrive in the hot weather. The desert tortoise is one that is able to live where ground temperature may exceed 140 degrees F because of its ability to dig underground burrows and escape the heat. At least 95% of its life is spent in burrows. Adult desert tortoises can survive for about a year without water.

Kangaroo rats are another underground desert dweller, living in dens which they seal off to block out midday heat and to recycle the moisture from their own breathing. Kangaroo rats can live their entire lives without drinking a drop of liquid. All of the water they need to survive can be metabolized within their bodies from starch and fats in the dry seeds they eat. They are also masters at conserving moisture; their kidneys have the ability to concentrate urine 4 to 5 times that of humans.

A camel is another one of those animals that has always been known for its ability to survive in the warmest conditions, however, there are many myths about the camel - one being that they store water in their hump and survive for weeks without drinking water. In truth, it can survive with very little water. The hump is a measure of the animal's health. It's composed of fat and supportive tissue and can be used as an extra ration for necessary energy and can also be metabolized into water when needed. The hump fat can eventually be used up just like any fat in a fasting situation.

Moisture from food is also a source of water and during a rainy, cool season a camel requires less water intake than in hot, dry weather. The camel can go without water for several days if food is provided. However, if it is getting neither food nor water, it weakens within two or three days. In very hot weather, a camel that has not drunk any water for a long time can drink up to 50 gallons at a time.

Turkey and black vultures have one of the most unusual ways of surviving the blistering hot sun. They are dark in color and thus absorb considerable heat in the desert. They excrete urine on their legs, cooling them by evaporation and circulate the cooled blood back through the body. This behavior, called urohydrosis, is shared with their relatives the storks, successful birds of the African deserts. Both vultures and storks may escape the hot midday temperatures of the desert by soaring effortlessly, high on thermals of cooler air.

Animal Adaptations for beating the heat

To stay cool, warm-blooded animals sweat or pant to loose heat by water evaporation. They can also cool off by moving into a shaded area or by getting wet. Only mammals can sweat. Primates, such as humans, apes and monkeys, have sweat glands all over their bodies. Dogs and cats have sweat glands only on their feet. Whales are mammals who have no sweat glands, but since they live in the water, they don't really need them. Large mammals can have difficulty cooling down if they get overheated. This is why elephants, for example, have large, thin ears which loose heat quickly.

Cold-blooded animals often like to bask in the sun to warm up and increase their metabolism. While basking, reptiles will lie perpendicular to the direction of the sun to maximize the amount of sunlight falling on their skin. They will also expand their rib cage to increase their surface area and will darken their skin to absorb more heat. When a reptile is too hot, it will lie parallel to the sun's rays, go into a shady area, open its mouth wide, lighten its skin color or burrow into cool soil.

Staying Cool at the Zoo

For those animals that aren't the biggest fans of the hot weather, we offer them lots of ways to stay cool at the Philadelphia Zoo.

The polar bears have a 200,000 galloon pool to take a dip in! In fact, practically every morning first thing they go for a swim. There exhibit also has a shade structure, a sprinkler and cool sand that they can roll around in. When the temperatures hit above 90-95 degrees, we bring in the huge blocks of ice (25-50 pounds) and place them in their pool. The keepers also often make "fishicles" or "applecicles" where the polar bears have to lick the ice down to get to the tasty treat!

Other animals in the Zoo that you'll see swimming or wading in their pools are the Amur tiger, black panther, Indian rhino, hippos, Humboldt penguins, flamingos, giant otters, and of course the elephants that completely submerge themselves.

Some animals even have air-conditioned dens in their exhibits. The Zoo's red pandas have a shade structure, a sprinkler and their very own air-conditioning. Under the rock shelf in their exhibit they can take a break from the sun and lounge in their cooled den.

In fact, all of the animals who need it have a place to take a break from the weather. See these pools, dens and misters in use and you know summer has arrived!

Learn more about the animals at the Zoo in the summer:
philadelphiazoo.blogspot.com/2006/05/hot-time-in-city.html

Check out your local zoo to see what the animals are doing in the summertime heat!