The Secret Life of Snowshoe Hares: A Tale of Survival and Growth

In the vast wilderness of Yukon, Canada, a fascinating story unfolds every 9 to 11 years. Snowshoe hares, those fluffy-footed creatures, go through dramatic population changes. But why and how this happens has puzzled scientists for nearly a century. Researchers recently dug into over 20, 000 captures of more than 7, 000 unique snowshoe hares from Kluane Lake. They wanted to understand the secrets behind these population cycles. What they found was surprising. Young hares, or juveniles, have the toughest time surviving. On the other hand, adult females who are reproducing have the best survival rates. This makes sense because they are the ones having babies, the future of the population. The study also revealed that the time of year matters a lot. Hares have better survival rates during the breeding season, especially in the middle and later parts. And guess what? When the population is growing, hares tend to do better overall. Now, here's where it gets interesting. As the population goes from low to growing, female hares are more likely to start reproducing and keep reproducing. This is a big deal because it means more baby hares are being born, helping the population grow. But the story doesn't end there. The researchers also found that the population grows fastest during the increase phase. This is when the hares have the shortest generation time, meaning they can reproduce and have babies quicker. However, when the population starts to decline, it's mainly because of lower survival rates, especially for baby hares before they are weaned. Reproduction also plays a role, but it's not the main factor. So, what does all this mean? It means that the population cycles of snowshoe hares are complex. Different things affect their growth and decline, depending on the time of year and the phase of the cycle. But there's still more to learn. The study suggests that while we know a lot about how predators affect hare survival, we need to understand more about how reproduction changes during these cycles. This could be the key to unlocking the full story of the snowshoe hare's secret life.