1. Climate Gradients: During an ice age, the poles become increasingly cold and inhospitable, while the equatorial regions remain relatively warmer. Animals tend to move towards areas with more favourable climates to escape the harsh conditions of the polar regions.
2. Food Availability: The extreme cold and glaciation of the polar regions reduce food availability, making it difficult for animals to find sustenance. By moving towards the equator, animals can access more abundant and diverse food sources in the warmer climates.
3. Reproduction and Survival: Many animal species have specific temperature requirements for reproduction and survival of their offspring. The warmer equatorial regions provide a more suitable environment for successful breeding and raising young, increasing their chances of survival.
4. Adaptations: Some animals have evolved adaptations that allow them to better withstand the cold conditions of the polar regions. These adaptations include thicker fur, layers of fat, and reduced body size. However, these adaptations may not be sufficient during severe ice ages, leading animals to seek more hospitable climates.
5. Population Dynamics: The migrations towards the equator can lead to population shifts and changes in species distribution. Some species may expand their ranges into new areas, while others may experience population declines or even extinction due to unfavourable conditions or competition from other species in the new environments.
It's important to note that the specific patterns of animal movement during ice ages can vary depending on the species, their ecological needs, and the severity of the ice age. Some animals may exhibit partial migrations, moving only short distances to find more suitable habitats, while others may undertake long-distance migrations to reach distant equatorial regions.