Urohidrosis (sometimes misspelled "urohydrosis") is the habit in some birds of defecating onto the scaly portions of the legs as a cooling mechanism, using

evaporative cooling An evaporative cooler (also known as evaporative air conditioner, swamp cooler, swamp box, desert cooler and wet air cooler) is a device that cools air through the evaporation of water. Evaporative cooling differs from other air conditioning sy ...

of the fluids. Birds' droppings consist of both feces and urine, which are excreted together through the

cloaca A cloaca ( ), : cloacae ( or ), or vent, is the rear orifice that serves as the only opening for the digestive (rectum), reproductive, and urinary tracts (if present) of many vertebrate animals. All amphibians, reptiles, birds, cartilagin ...

Etymology

Hidrosis" is the medical term for

sweat Perspiration, also known as sweat, is the fluid secreted by sweat glands in the skin of mammals. Two types of sweat glands can be found in humans: eccrine glands and Apocrine sweat gland, apocrine glands. The eccrine sweat glands are distribu ...

ing from

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

, and the word "urohidrosis" was coined by M. P. Kahl in 1963:

...Because of its apparent functional similarity to true sweating, I suggest the term ''urohidrosis'' (Greek: ''ouron'' = urine; ''hidrōs'' = sweat) for this phenomenon.

Examples

Several species of

stork Storks are large, long-legged, long-necked wading birds with long, stout bills. They belong to the family Ciconiidae, and make up the order Ciconiiformes . Ciconiiformes previously included a number of other families, such as herons and ibise ...

s and

New World vulture Cathartidae, known commonly as New World vultures or condors, are a family (biology), family of birds of prey consisting of seven extant species in five genus, genera. It includes five extant vultures and two extant condors found in the Americas. ...

s exhibit this behaviour. This behaviour leads to accumulation of droppings around leg rings on ringed birds, which can lead to injury. The term is also used to describe the analogous behaviour in seals that cool themselves while basking by urinating on their hind flippers.

References

Bird behavior {{ornithology-stub