Daily Torpor, sometimes called
temporary hibernation is a (usually short-term) state of decreased physiological activity in an animal, usually characterized by a reduced body temperature and rate of
metabolismMetabolism is the set of chemical reactions that occur in living organisms to maintain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories. Catabolism breaks down organic matter,...
. Animals that go through torpor include birds (even tiny hummingbirds, notably
CypselomorphaeCypselomorphae is a clade of birds. It includes the living families and orders Caprimulgidae , Nyctibiidae , Apodiformes , as well as the Aegotheliformes whose distinctness was only recently realized...
) and some mammals such as
miceMICE is an acronym for:*Muon Ionization Cooling Experiment*"Money, Ideology, Compromise, Ego", four factors by which spies may be recruited. See MICE .*"Meetings, Incentives, Conferencing, Exhibitions", terminology for banquets, etc., in a hotel....
, and
batBats are flying mammals in the order Chiroptera . The forelimbs of bats are webbed and developed as wings, making them the only mammals naturally capable of true and sustained flight. By contrast, other mammals said to fly, such as flying squirrels, gliding possums and colugos, glide rather than...
s. During the active part of their day, animals that undergo daily torpor maintain normal body temperature and activity levels, but their temperature drops during a portion of the day (usually night) to conserve energy.
Daily Torpor, sometimes called
temporary hibernation is a (usually short-term) state of decreased physiological activity in an animal, usually characterized by a reduced body temperature and rate of
metabolismMetabolism is the set of chemical reactions that occur in living organisms to maintain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories. Catabolism breaks down organic matter,...
. Animals that go through torpor include birds (even tiny hummingbirds, notably
CypselomorphaeCypselomorphae is a clade of birds. It includes the living families and orders Caprimulgidae , Nyctibiidae , Apodiformes , as well as the Aegotheliformes whose distinctness was only recently realized...
) and some mammals such as
miceMICE is an acronym for:*Muon Ionization Cooling Experiment*"Money, Ideology, Compromise, Ego", four factors by which spies may be recruited. See MICE .*"Meetings, Incentives, Conferencing, Exhibitions", terminology for banquets, etc., in a hotel....
, and
batBats are flying mammals in the order Chiroptera . The forelimbs of bats are webbed and developed as wings, making them the only mammals naturally capable of true and sustained flight. By contrast, other mammals said to fly, such as flying squirrels, gliding possums and colugos, glide rather than...
s. During the active part of their day, animals that undergo daily torpor maintain normal body temperature and activity levels, but their temperature drops during a portion of the day (usually night) to conserve energy. Torpor is often used to help animals survive during periods of colder temperatures, as it allows the organism to save the amount of energy that would normally be used to maintain a high body temperature.
Torpor may extend for a longer period of time. Some animals such as
groundhogThe groundhog , also known as a woodchuck or whistle-pig, or in some areas as a land-beaver is a rodent of the family Sciuridae, belonging to the group of large ground squirrels known as marmots. Other marmots, such as the yellow-bellied and hoary marmots, live in rocky and mountainous areas, but...
s,
ground squirrelRound-tailed Ground Squirrels , known as "Ardillón cola redonda" in Spanish, live in the desert of the Southwestern United States and adjacent Mexico. They are called "ground squirrels" because they burrow in loose soil, often under mesquite trees and creosote bushes.-Characteristics:Most...
s and jumping mice enter this intensely deep state of
hibernationHibernation is a state of inactivity and metabolic depression in animals, characterized by lower body temperature, slower breathing, and lower metabolic rate. Hibernating animals conserve energy, especially during winter when food is short, tapping energy reserves, body fat, at a slow rate...
for the duration of the winter.
LungfishLungfish are freshwater fish belonging to the Subclass Dipnoi. Lungfish are best-known for retaining characteristics primitive within the Osteichthyes, including the ability to breathe air, and structures primitive within Sarcopterygii, including the presence of lobed fins with a well-developed...
switch to the torpor state if their pool dries out;
tenrecsTenrecidae is a family of mammals found on Madagascar and parts of Africa. Tenrecs are widely diverse, resembling hedgehogs, shrews, opossums, mice and even otters, as a result of parallel evolution. They occupy aquatic, arboreal, terrestrial and fossorial environments...
switch to the torpor state if food is scarce during the summer in Madagascar. This prolonged and deep torpor during summer months is known as
aestivationEstivation or aestivation , also known as "summer sleep", is a state of animal dormancy somewhat similar to hibernation...
.
Black bearBlack bear may refer to:In mammals:*American Black Bear*Asian Black Bear, including its subspecies** Formosan Black Bear** Himalayan Black BearIn places:*Black Bear Creek, a creek in Oklahoma*Black Bear Ranch, a commune in California...
s, although often thought of as hibernators, do not truly enter a state of torpor: while their body temperatures lower along with respiration and heartbeat, they do not decrease as significantly as most animals in a state of torpor, and bears are still responsive. Still, there is much debate about this within the scientific community: some feel that black bears are true hibernators that employ a more advanced form of hibernation.
Bats, especially species in temperate regions suffering harsh winters, rely upon torpor to survive. Lowering the body temperature to the ambient temperature allows them to enter torpor for prolonged periods at a lower metabolic cost. Oxygen consumption, heart rate and breathing rates are all lowered significantly meaning less energy is required to survive. Torpor is important in daily cycles to conserve energy as well as prolonged torpor, or hibernation. Pre-hibernation feeding builds up layers of fat which are used as the energy source during torpor. Arousal from torpor in bats is facultative, not obligate, but comes at a high energy cost, meaning awakening must be for a good reason.
Other uses of the word
Torpor is alternatively used as a reference to any non-physiological state of inactivity. As an example, recently naturalists have learned that female crocodiles enters a deep torpor without aggression during their short egg laying period.