Prey defences

Predation defence Predation defence comes in many forms: physiological, anatomical and behavioural. Physical defences such as spines and armour are obvious adaptations, but other defences can be more subtle and surprising. Whether it's avoiding detection through camouflage and mimicry, chemical defence through being poisonous or exuding irritants, it's all about one thing: avoiding being eaten. Some animals rely on increasing their chances of detecting predators by living in groups and using alarm calls to warn each other of danger.http://www.bbc.co.uk/nature/adaptations/Antipredator_adaptation#introOften the first line of defense is to avoid being detected by the predator. One way to do this is to minimize noise production and any visual cues that the predator might use to locate the prey. Frogs and crickets usually stop singing as another creature approaches. The resulting silence makes it more difficult for the predator to find them. Other prey have evolved camouflage coloration that blends into the background making it difficult for visual predators to find them. Many moths, common prey for birds, look like the bark of trees on which they rest during the day, and snowshoe hares, the primary prey for lynx, have brown fur in the summer but white fur in the winter when their northern environment is covered with snow. Because predators often use prey movements to detect them, many prey remain as still as possible when a predator approaches.Many prey species are very fast runners, swimmers, or fliers, and they often can use their speed to escape. Many fish and insects have spines that prevent a predatory fish or bird from being able to eat them. Some prey, like the puffer fish, make themselves larger if threatened, again making it more difficult, often impossible, for the predator to ingest the prey.Many species of fish and birds travel in groups, such as schools of fish and flocks of birds. Some prey are easy for predators to find, easy for predators to capture, and easy for predators to ingest. Yet they seldom fall prey to predators because they employ a final line of defense: toxicity. They are poisonous.