Many environments vary beyond the tolerable limits for normal metabolic activity for any particular organism.

Some animals have adapted to survive these adverse conditions while others avoid them.

Adverse conditions can be survived by dormancy.

→ During dormancy there is a decrease in metabolic rate, heart rate, breathing rate and body temperature.

→ The metabolic rate can be reduced during dormancy to save energy.

→ Dormancy is part of some organisms’ life cycle to allow survival during a period when the costs of continued normal metabolic activity would be too high.

Dormancy can be predictive or consequential.

Predictive dormancy occurs before the onset of adverse conditions.

Consequential dormancy occurs after the onset of adverse conditions.

Aestivation allows survival in periods of high temperature or drought.

Daily torpor is a period of reduced activity in some animals with high metabolic rates.

Some mammals survive during winter/low temperatures by hibernating.

Adverse conditions can be avoided by migration.

→ Migration avoids metabolic adversity by expending energy to relocate to a more suitable environment.

Migratory behaviour can be innate and learned.

Specialised techniques are used to study long-distance migration.

Examples of specialist techniques to study long-distance migration are satellite tracking and leg rings.