Adaptation and competition in animals

To survive in cold climates, animals have to stay warm. This means they are adapted to reduce the heat they lose through their bodies.

Surface area to volume ratio is how big an object's surface area is compared to its volume. The ratio of surface area to volume decreases as objects get bigger. This means that larger objects have a smaller surface area compared to its volume.

Arctic animals have a small surface area to volume ratio as they tend to be big, meaning they can retain more heat because they have less surface area to lose heat from.

Blubber is a thick layer of fat which builds up under the skin, which insulates animals in cold environments. A thick fur coat is also insulating. Blubber also provides a food supply - animals often eat a lot to build up their fat in the summer so in the winter, when food is scarce, they can live off their body fat.

Camoflage is important to predators, so prey can't see them, and prey, so predators can't find them. Many Arctic animals are brown or grey in the summer and white in the winter to be camoflaged.

Dry, hot climates, like deserts, are hot during the day but cold at night. Water is hard to find.

Desert animals are adapted to need less water, and they get water from their food. They are most active in the early morning or late evening when the temperature is comfortable, and they rest for the night and day in burrows where the temperature doesn't change much.

Desert animals are usually small so they can lose more heat through having a larger surface area compared to their volume. If they have fur, then it is silky and fine, and they have little fat.

Animals compete for:

• Water
• Territory
• Food
• Mates
• Breeding sites

A territory is an area where animals live and feed. It will be large enough to find water and food, and have space for breeding.

Predators compete with their prey because they want to eat them. Predators compete with each other to get food and prey animals compete to find food and escape predators. Some animals are poisonous and have warning colours so predators won't eat them.

REMEMBER: The larger the animal the smaller the surface area : volume ratio. Animals have bigger surface areas in hot climates and smaller surface areas in cold climates.