Search results
Results from the WOW.Com Content Network
Sleep can follow a physiological or behavioral definition. In the physiological sense, sleep is a state characterized by reversible unconsciousness, special brainwave patterns, sporadic eye movement, loss of muscle tone (possibly with some exceptions; see below regarding the sleep of birds and of aquatic mammals), and a compensatory increase following deprivation of the state, this last known ...
Crepuscular, a classification of animals that are active primarily during twilight, making them similar to nocturnal animals. Diurnality, plant or animal behavior characterized by activity during the day and sleeping at night. Cathemeral, a classification of organisms with sporadic and random intervals of activity during the day or night.
The primary physiological and biochemical concerns for an aestivating animal are to conserve energy, retain water in the body, ration the use of stored energy, handle the nitrogenous end products, and stabilize bodily organs, cells, and macromolecules. This can be quite a task as hot temperatures and arid conditions may last for months, in some ...
Pinnipeds spend many months at a time at sea, so they must sleep in the water. Scientists have recorded them sleeping for minutes at a time while slowly drifting downward in a belly-up orientation. [83] Like other marine mammals, seals sleep in water with half of their brain awake so that they can detect and escape from predators, as well as ...
Hibernation functions to conserve energy when sufficient food is not available. To achieve this energy saving, an endothermic animal decreases its metabolic rate and thereby its body temperature. [3] Hibernation may last days, weeks, or months—depending on the species, ambient temperature, time of year, and the individual's body-condition.
It usually sleeps lying down; however, standing sleeps have been recorded, particularly in older individuals. Intermittent short "deep sleep" phases while lying are characterised by the giraffe bending its neck backwards and resting its head on the hip or thigh, a position believed to indicate paradoxical sleep .
The water opossum (Chironectes minimus), also locally known as the yapok (/ ˈ j æ p ɒ k /), is a marsupial of the family Didelphidae. [3] It is the only monotypic species of its genus , Chironectes . [ 4 ]
The correlates of sleep found for mammals are valid for birds as well i.e. bird sleep is very similar to mammals and involves both SWS and REM sleep with similar features, including closure of both eyes, lowered muscle tone, etc. [37] However, the proportion of REM sleep in birds is much lower. Also, some birds can sleep with one eye open if ...