Tachyglossus aculeatusshort-beaked echidna

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Geographic Range

Tachyglossus aculeatus is the most widely distributed extant monotreme. Subspecies of T. aculeatus are distributed throughout southern and eastern New Guinea, mainland Australia, Kangaroo Island, and Tasmania. This range includes large portions of the three countries of Australia, Indonesia, and Papua New Guinea. ("Tachyglossus aculeatus", 1991; Aplin, et al., 2008; Groves, 2005)

Habitat

Short-beaked echidnas thrive in a variety of habitats including open woodlands, savanna, agricultural areas, semi-arid, and arid regions. Both coastal and highland areas in New Guinea are home to Tachyglossus aculeatus, along with a range of ecosystems in Australia from mild coastal regions to above snowline. Short-beaked echidnas have a broad altitudinal range from sea level to at least 1,675 meters. (Aplin, et al., 2008; Nicol and Anderson, 2007a)

  • Range elevation
    0 to 1,675 m
    0.00 to ft

Physical Description

Short-beaked echidnas are medium-sized mammals ranging in length from about 30 to 40 cm and in weight from about 2 to 7 kg. Depending on the subspecies and location, males or females may be larger. Short-beaked echidna spines are one of their most distinguishing characteristics. These spines cover the entire dorsal surface, including a small tail. Fur is also present and may be even longer than the spines in some subspecies. Tachyglossus aculeatus lacks external pinnae and teeth but does have hard pads in the back of the mouth. Short-beaked echidnas possess several adaptations to their foraging habits including tubular snouts, long sticky tongues, and front paws for digging. Males have non-venomous spurs on the ankles of their hind legs and females have pouches on their undersides. Both males and females have a cloaca through which feces, urine, and, in females, eggs pass. Males have penises they extend through the cloaca during mating. Short-beaked echidnas, and other monotremes, have low metabolic rates and low body temperatures, which may be related to such factors as diet and environmental variation. Short-beaked echidnas have larger brains than would be expected for their body mass. The cerebral cortex, in particular, is large and highly convoluted. (Nicol and Anderson, 2007a; Riek, 2008)

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    2 to 7 kg
    4.41 to 15.42 lb
  • Range length
    30 to 45 cm
    11.81 to 17.72 in
  • Average basal metabolic rate
    2.327 W
    AnAge

Reproduction

Tachyglossus aculeatus has a courtship period between June and August that can last between a few days and several weeks depending on geographic region and subspecies. Females may be pursued by one or several males during this period. Observations of multiple males following individual females have led to the term “echidna train.” Females will mate with only one male per season. (Nicol and Anderson, 2007a)

Gestation in Tachyglossus aculeatus lasts about 23 days, after which the female will lay a single soft-shelled egg in her pouch for incubation. Eggs hatch 10 or 11 days later. Short-beaked echidnas exhibit a long lactation stage lasting between 150 and 200 days depending on geography and subspecies. When the young leave the pouch three months later, they are covered with spines. Maturation time is lengthy. Young reach full adult size after three to five years. Hatchlings have a mass of about 0.3 kg but will grow to weigh 0.7 to 2.1 kg by weaning. Weaning mass is 28 to 48% of adult mass. ("Tachyglossus aculeatus", 1991; Aplin, et al., 2008; Nicol and Anderson, 2007a)

  • Breeding interval
    Short-beaked echidnas breed once a year.
  • Breeding season
    Mating usually occurs June through August.
  • Range number of offspring
    1 to 1
  • Average number of offspring
    1
    AnAge
  • Average gestation period
    23 days
  • Average gestation period
    22 days
    AnAge
  • Range weaning age
    150 to 200 days
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    548 days
    AnAge
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    548 days
    AnAge

Subspecies vary in their strategies of caring for young. Short-beaked echidnas on Kangaroo Island forage with the young in the pouch immediately post-hatching. After 45 to 55 days, mothers will deposit their young in nursery burrows, where the young will remain until weaning. Mothers return every five to ten days to nurse the young. Short-beaked echidnas in Tasmania remain in nursery burrows with the young for 25 to 35 days post-birth. Mothers then return to the burrow every three to five days to nurse. Other subspecies exhibit variations of parental care ranging between these two extremes. Mothers do not have nipples or teats, but nurse young through pores connected to their paired mammary glands. (Nicol and Anderson, 2007a)

  • Parental Investment
  • altricial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female

Lifespan/Longevity

The longest recorded lifespan for Tachyglossus aculeatus is 50 years in captivity. There are anecdotal accounts of wild individuals living as long as 45 years. There is no doubt this species is particularly long-lived, especially for its size. A lifespan of 50 years is 3.7 times longer than would be expected based on echidna body size. Other long-lived mammals have been observed to have peroxidation-resistant membrane composition, which describes the ratio between polyunsaturates and monounsaturates in membrane lipids. Short-beaked echidna membranes were found to have lower polyunsaturate and higher monounsaturate levels than expected. This composition indicates peroxiclation-resistant cellular membranes in T. aculeatus. Lifespan is also associated with the production of free radicals, which is proportional to metabolic rate. Short-beaked echidnas have notably low metabolic rates, with the exception of times of arousal from torpor. During these arousal periods, metabolic rates increase by up to nine times that of basal metabolic rates and free radical production is high. Therefore, T. aculeatus is thought to have stress resistance that contributes to a long lifespan. A large and complexly-structured brain may be involved with longevity in T. aculeatus. Such brain characteristics are often correlated with life history traits like slow maturation and single births in other mammals. These traits, in turn, correlate with a long lifespan. (Hulbert, et al., 2008; Nicol and Anderson, 2007a)

Behavior

Short-beaked echidnas are semi-fossorial, digging in substrate for hibernation cover and to construct nursery burrows. They decrease energy usage by hibernating from early autumn to late spring. Short-beaked echidnas reduce their body temperature to 8 to 10 degrees C during torpor and use behavioral thermoregulation to maintain that preferred body temperature. During early hibernation, individuals prefer cooler soil temperatures compared with the coldest period of hibernation, at which time they will move to warmer hibernacula. During hibernation there are periodic arousals from torpor. The timing of hibernation seasons varies by subspecies, geographic location, sex, and reproductive state. Short-beaked echidnas are flexible in their exploitation of substrates for hibernacula, commonly using leaf litter and grass tussocks. (Nicol and Anderson, 2007b; Nicol and Anderson, 2007a)

Home Range

Short-beaked echidnas nest at temporary sites, and have overlapping home ranges. Their movements depend on food availability and not territoriality. ("Tachyglossus aculeatus", 1991; Nicol and Anderson, 2007a)

Communication and Perception

Short-beaked echidnas sense other echidnas predominantly through smell. Recent findings suggest feces piles act as an important intra-specific form of communication. (Elridge and Mensing, 2007; Nicol and Anderson, 2007a)

Food Habits

Adult short-beaked echidnas eat ants, termites, and other invertebrates. They make foraging pits by disturbing the soil when looking for food, and they prefer foraging under the canopies of large trees. Their long snouts and sticky tongues reflect their specialized diet. Short-beaked echidnas dig into ant and termite nests with their front paws and poke their long, sticky tongue into nest crevices and grinds insects with its tooth pads. Their foraging habits make separating soil from food difficult. Thus, much of their feces consists of soil. (Elridge and Mensing, 2007; Nicol and Anderson, 2007a)

  • Animal Foods
  • insects
  • terrestrial non-insect arthropods

Predation

Predation is not a major threat to short-beaked echidnas, even though feral cats, pigs, dingoes, and goannas are occasional predators. Animal predators are mostly a threat to young in burrows and to subadults. Adults escape predation by hiding beneath rocks or logs, or digging into the ground until only the spiny back is exposed. Short-beaked echidnas can also curl up to protect their undersides. Despite the minimal defense of many hibernaculum materials, predation on hibernating individuals does not seem to be a problem. After introduced predators, the biggest influence on T. aculeatus mortality is the threat of motor vehicles. Over-hunting by humans may become a problem in some areas of New Guinea. (Aplin, et al., 2008; Nicol and Anderson, 2007a)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

The foraging pits short-beaked echidnas create become resource traps and affect soil biogeochemistry. Tachyglossus aculeatus may be important in maintaining proper nutrient circulation through small-scale patchiness in semi-arid regions. (Elridge and Mensing, 2007)

Economic Importance for Humans: Positive

Short-beaked echidnas are hunted for food and for ceremonial purposes, especially in New Guinea. They maintain small-scale patchiness, which is an important ecosystem service that keeps semi-arid regions functioning properly. Their diet of ants, termites, and other invertebrates may contribute to the control of these species. (Aplin, et al., 2008; Elridge and Mensing, 2007; Nicol and Anderson, 2007a)

  • Positive Impacts
  • food
  • body parts are source of valuable material
  • controls pest population

Economic Importance for Humans: Negative

Because short-beaked echidnas can live in agricultural areas, they may disrupt fields and gardens while foraging. (Nicol and Anderson, 2007a)

  • Negative Impacts
  • crop pest

Conservation Status

As of 2008, the IUCN listed Tachyglossus aculeatus as a species of Least Concern. Short-beaked echidnas have a broad distribution, a large total population with a stable trend, and are tolerant of many habitat types. They occur in protected areas and appear to lack major threats. The IUCN did suggest monitoring the number of T. aculeatus killed on major tourist roads. (Aplin, et al., 2008)

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Michelle Cason (author), University of Alaska Fairbanks, Link Olson (editor, instructor), University of Alaska Fairbanks.

Glossary

Australian

Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

World Map

agricultural

living in landscapes dominated by human agriculture.

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

crepuscular

active at dawn and dusk

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

desert or dunes

in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.

diurnal
  1. active during the day, 2. lasting for one day.
endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

fertilization

union of egg and spermatozoan

food

A substance that provides both nutrients and energy to a living thing.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

fossorial

Referring to a burrowing life-style or behavior, specialized for digging or burrowing.

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

hibernation

the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.

insectivore

An animal that eats mainly insects or spiders.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

mountains

This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

polygynous

having more than one female as a mate at one time

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

scrub forest

scrub forests develop in areas that experience dry seasons.

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

soil aeration

digs and breaks up soil so air and water can get in

solitary

lives alone

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

References

1991. Tachyglossus aculeatus. Pp. xviii-xix, 2-3 in R Strahan, ed. The Australian Museum Complete Book of Australian Mammals. New South Whales: Cornstalk Publishing.

Aplin, K., C. Dickman, L. Salas, K. Helgen. 2008. Tachyglossus aculeatus. 2008 IUCN Redlist of Threatened Species. Accessed November 15, 2008 at www.iucnredlist.org.

Elridge, D., A. Mensing. 2007. Foraging pits of the short-beaked echidna (Tachyglossus aculeatus) as small-scale patches in a semi-arid Australian woodland. Soil Biology & Biochemistry, 39: 1055-1065.

Groves, C. 2005. Tachyglossus aculeatus. Pp. 1-2 in D Wilson, D Reeder, eds. Mammal Species of the World: A Taxonomic Reference, Vol. 1. Washington: Smithsonian Institution Press.

Hulbert, A., L. Beard, G. Grigg. 2008. The exceptional longevity of an egg-laying mammal, the short-beaked echidna (Tachyglossus aculeatus) is associated with peroxidation-resistant membrane composition. Experimental Gerontology, 43: 729-733.

Nicol, S., N. Anderson. 2007. Cooling rate and body temperature regulation of hibernating echidnas (Tachyglossus aculeatus). Journal of Experimental Biology, 210: 586-592.

Nicol, S., N. Anderson. 2007. The history of an egg-laying mammal, the echidna (Tachyglossus aculeatus). Ecoscience, 14: 275-285.

Riek, A. 2008. Relationship between metabolic rate and body weight in mammals: effect of the study. Journal of Zoology, 276: 187-194.