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.
- Biogeographic Regions
- australian
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.
- Habitat Regions
- temperate
- tropical
- terrestrial
- Terrestrial Biomes
- desert or dune
- savanna or grassland
- forest
- rainforest
- scrub forest
- mountains
- Other Habitat Features
- agricultural
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.
- Other Physical Features
- endothermic
- heterothermic
- bilateral symmetry
- Sexual Dimorphism
- sexes alike
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.
- Mating System
- polygynous
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.
- Key Reproductive Features
- iteroparous
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- fertilization
- oviparous
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.
- Parental Investment
- altricial
-
pre-fertilization
- provisioning
-
protecting
- female
-
pre-hatching/birth
-
provisioning
- female
-
protecting
- female
-
provisioning
-
pre-weaning/fledging
-
provisioning
- female
-
protecting
- female
-
provisioning
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.
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.
- Key Behaviors
- terricolous
- fossorial
- diurnal
- nocturnal
- crepuscular
- motile
- sedentary
- hibernation
- solitary
Home Range
Short-beaked echidnas nest at temporary sites, and have overlapping home ranges. Their
movements depend on food availability and not territoriality.
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.
- Communication Channels
- chemical
- Other Communication Modes
- scent marks
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.
- Primary Diet
- carnivore
- 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.
- 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.
- Ecosystem Impact
- creates habitat
- soil aeration
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.
- 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.
- 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.
Additional Links
Contributors
Tanya Dewey (editor), Animal Diversity Web.
Michelle Cason (author), University of Alaska Fairbanks, Link E. Olson (editor, instructor), University of Alaska Fairbanks.
- Australian
-
Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- 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).
- tropical
-
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
- terrestrial
-
Living on the ground.
- 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.
- 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.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- 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.
- scrub forest
-
scrub forests develop in areas that experience dry seasons.
- mountains
-
This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.
- agricultural
-
living in landscapes dominated by human agriculture.
- 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.
- 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.
- 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.
- polygynous
-
having more than one female as a mate at one time
- 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).
- seasonal breeding
-
breeding is confined to a particular season
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- fertilization
-
union of egg and spermatozoan
- oviparous
-
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
- 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.
- fossorial
-
Referring to a burrowing life-style or behavior, specialized for digging or burrowing.
- diurnal
-
- active during the day, 2. lasting for one day.
- nocturnal
-
active during the night
- crepuscular
-
active at dawn and dusk
- motile
-
having the capacity to move from one place to another.
- sedentary
-
remains in the same area
- 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.
- solitary
-
lives alone
- chemical
-
uses smells or other chemicals to communicate
- scent marks
-
communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them
- 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.
- soil aeration
-
digs and breaks up soil so air and water can get in
- food
-
A substance that provides both nutrients and energy to a living thing.
- carnivore
-
an animal that mainly eats meat
- insectivore
-
An animal that eats mainly insects or spiders.
- tactile
-
uses touch to communicate
- chemical
-
uses smells or other chemicals to communicate
References
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 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.
1991. Tachyglossus aculeatus . Pp. xviii-xix, 2-3 in The Australian Museum Complete Book of Australian Mammals . New South Whales: Cornstalk Publishing.