Frog - VU

Frogs are ectotherms, this means they get their heat from external sources. Frogs can live in a number of different environments, as they have different ways in which they can regulate their internal conditions (depending on the external environment). For example, certain frogs can change their colour to control the amount of solar radiation that they receive, or they can control the absorption and the evaporation of water through the skin. They also have other behavioural adaptations such as moving to the shade in hotter weather or basking in the sun to warm up. Frogs tend to bask in moist areas rather than really hot areas to minimise water loss. Increased body temperature accelerates growth, digestion and produces fat deposits and thus is important to frogs. Physiological adaptations of frogs include converting glycogen into glucose to produce an 'antifreeze' to stop body fluids freezing in cooler temperatures (e.g. Winter). They also become stiff with no breathing or heart rate. Frogs living in hotter conditions have different adaptations to those that live in cooler temperatures. Some frogs store water in their bladder, as well as closing their eyes, tucking their limbs in or huddling together with other frogs to minimise water loss by reducing surface area.