Written by author and ABNC EcoEducation Instructor Rebekah Gano

Can you see all the turtles resting in the Rotary Pond water? Photo by Zoey Prevost

When it gets cold at the nature center, many of the animals we typically see are not around. The frogs and turtles are not swimming in the ponds. The butterflies, grasshoppers and beetles seem to have vanished. Even the birds are quieter. Where do they go, and how do they survive when the weather gets cold?

The answer is: they are dormant. Many things in nature enter dormancy, from volcanoes to plants to animals. Dormancy is like hitting a pause button. Volcanoes stop erupting. Plants lose their leaves. Animals use the minimum amount of energy needed to stay alive.

Animals survive cold temperatures in a variety of ways. Most animals do not truly hibernate in the semi-tropical climate along the Gulf Coast. Bats are one of the few that hibernate; they roost together, their body temperatures drop, and their hearts slow down as they sleep deeply. Some frogs will also bury themselves in mud and hibernate for weeks or months until spring arrives.

Instead of hibernating, most reptiles and amphibians at Armand Bayou Nature Center brumate. Being cold-blooded, reptiles and amphibians can easily slow their bodies down. They often cover themselves with leaves and mud, hide in burrows, or rest underwater until temperatures warm up and they can bask in the sunshine. Many reptile and amphibian species can also create a sugary syrup (glucose) that keeps their bodies from freezing, much like tree sap helps trees survive frigid weather.

Insect dormancy is called diapause and is very similar to brumation. Insects search for shelter as temperatures drop, and they often huddle together for extra warmth. Many curl up under fallen logs, where the decomposition process creates extra heat. During diapause insects typically decrease the amount of water in their bodies and stiffen up. They can enter diapause as adults, larvae, pupae, or eggs and reanimate when environmental conditions improve.

Birds have different strategies for surviving cold weather, given that they are warm-blooded. Birds fluff up their feathers, which they have more of in the winter, for extra warmth. Many species will huddle together for warmth or take shelter in a tree cavity, birdhouse or evergreen. If it gets particularly frigid, birds may enter torpor. In this kind of dormancy, birds’ body temperatures and heart rates decrease. It is much like a mini hibernation, with the birds in torpor for just a few hours. While in torpor, the birds’ bodies are so sluggish that their heads hang down. Hummingbirds’ entire bodies may fall upside down, with their feet clamped onto a branch.

In all these types of dormancy, animals find ways to slow down and save energy so that when the weather warms again, they are ready to soak up the sun, find food and have energy for moving.

Note: Many of these facts are from the book Wait, Rest, Pause: Dormancy in Nature by Marcie Flinchum Atkins. This is a wonderful book for kids of all ages; adults will enjoy the photos and information too.

Animal Dormancy at ABNC