Things change as the temperature dips! Caring for the Oklahoma City Zoo’s diverse animal collection (over 300 species!) through all the seasons requires caretakers to be familiar with their animals’ natural behaviors to make them comfortable year-round.
As an over-arching concept, animals can be found in “tropical” or “polar”, with “temperate” areas of the world in between the extremes. Those adapted to tropical areas are less naturally able to acclimate to temperature change when compared to those species found in areas that experience more seasonal changes in climate. This increases as you move away from the equator. However, interesting things happen when you consider those species that have long migration pattern, changes due to altitude, or have adapted to desert life where the difference from daytime to nighttime temperatures can be extreme… which results in animals that have a surprising ability to acclimate or adjust.
Oklahoma’s winter season is marked by a very noticeable decrease in grass/plant growth. Herbivores like the bison and zebra that rely on grazing in their habitats during the summer have their Bermuda hay increased substantially. The zebra gets two servings in summer but is increased to eight in winter! The bison go from four to 13! To keep them active in the winter, we also provide hay three to four times per day instead of twice in the summer.
Our California sea lions and harbor seals also get a diet increase to put on a few extra pounds to help insulate their bodies from the colder air. Their pool is heated to 72 degrees but natural weight gains and consequent loss later on is a normal cycle they experience in the wild and is considered a healthy pattern.
Opposite of this, our two grizzly bears are fed more and gain weight in late summer/early fall so they have the poundage already in place when natural instinct tells them it is time to begin their semi-hibernation. The Oklahoma City Zoo is one of the few places where you can watch a bear actually dig a den for winter! At this time of the year, the bears diets are reduced because they naturally fast during their inactive period.
All of our animals have the necessary areas that provide appropriate warmth. Depending on the species and facility, they can either be kept in their indoor habitat or have access outdoors based on ambient temperature. As an example, more “tropical” animals like the giraffe and okapi are given access to their indoor habitats when temperatures are below 45-50 degrees. Of course, this isn’t much of an issue for animals native to more “temperate” climates like the white-tailed deer! Even for animals acclimated to cooler weather, we provide extra beds of straw to cushion and insulate them from the cold ground which helps them not expend as much body heat. The red panda enjoys the colder weather and are noticeably more active on cool mornings or during snow events!
An interesting exhibit feature that we have incorporated into the African lion, Sumatran tiger, clouded leopards and the small cat exhibits are “hot rocks”. These artificially heated features provide a warm place to lay and encourage the animals to spend more time outdoors.
Reptiles and amphibians rely on ambient weather to thermos-regulate. Most have indoor habitats where relatively consistent room temperatures are maintained with additional “hot spots” to create a gradient that they can choose. Those more “temperate” species like the alligators and alligator snapping turtle slow their activity level and metabolism down and naturally go through the winter season outdoors.
Interestingly, for some species to reproduce, caretakers must “cool them down” for a period to mimic a seasonal temperature drop to stimulate this response!
Some animals, like the elephants and rhinos, have heated floors to make them even more comfortable. Many species will spend short periods of time outdoors, then go inside to warm up and head straight back outdoors. It is part of the Oklahoma winter experience!
-Kevin Drees, director of animal collections