How Animals Survive the Winter
Strategies to Brave the Cold Season - Part 1
Winter is here again, and the temperature has been steadily dropping. For the past few weeks, it's been consistently below freezing. When I head out for a walk with my dog or a run, I bundle up with my jacket, hat, and gloves. It's easy to stay warm with the right clothing—the cold doesn't bother me. But have you ever wondered how animals stay warm when temperatures plummet? What strategies has nature come up with to help them endure the harsh winter months?
In this post, I’ll take a closer look at the ingenious ways animals survive the winter. As I started writing, I realized there’s a lot to explore, so I decided to split this topic into shorter, bite-sized reads. Stay tuned for more parts sprinkled throughout this winter season as we uncover the secrets of how animals tackle the cold!
The first strategy animals use to survive the winter is straightforward—they leave. Instead of braving the cold, many animals simply migrate to warmer regions. This is especially true for birds, but the cold itself isn’t always the main problem. Many birds could handle freezing temperatures if they had to, but the scarcity of food during winter is a much bigger challenge. When their summer homes can no longer provide enough sustenance, it’s time to take off.
Well, maybe not simply take off… Migration is a long and grueling journey requiring remarkable precision. Birds navigate with tools we can only marvel at: they use the sun as a compass, recognize visual landmarks, and even rely on the Earth’s magnetic field to guide them. They have special protein in their eyes called cryptochrome 4. This protein is sensitive to magnetic fields and allows them to sense Earth’s magnetic field. Isn't it amazing that a bird can fly hundreds or even thousands of kilometers, using the sun, magnetic fields, and familiar sights to find its way?
But how do they know when to start and what do they do to prepare? There are different ways birds know that winter is approaching. First, birds notice the change in day lengths. Also, food becomes scarcer. Birds also notice the decline in temperature. This causes the birds' hormones to change. These hormonal changes change the birds' digestive patterns. Because they go on a long journey, they must gain weight and build up muscles. They undergo hyperphagia, a phase of extreme hunger in the weeks before they fly off, to beef up. In this phase, the birds store fat and some even nearly double their body weight.
Migrating birds fall into three categories: short-distance, mid-distance, and long-distance migrants. Short- and mid-distance migrants typically travel less than 2,000 km. These birds spend their summers in northern Europe or North America and migrate to the Mediterranean or warmer regions to escape the cold. Long-distance migrants undertake incredible journeys. They migrate from Europe or North America to regions such as Africa, South America, or even Antarctica. Butterflies and bats also migrate to warmer climates to escape the winter chill. Interestingly, not all migrations are weather-related: take wildebeests, for example. They embark on an epic trek across the Serengeti, walking up to 1,000 km. The exact reasons for their migration remain a mystery, although it’s likely connected to food and water availability.
So, that's a quick look at migration, one of many fascinating strategies animals, including birds, use to tackle the cold. In future posts, I'll explore more of these strategies, from hibernation to clever adaptations that allow animals to endure even the harshest conditions. Thank you for taking the time to read my first post here on Substack. I hope you enjoyed it! Stay tuned for more about how animals survive the winter, as well as posts on a variety of other topics that spark my curiosity.