Animal Diversity Web

Di­ver­sity

The fam­ily Tachy­glos­si­dae con­sists of two gen­era of echid­nas, Tachy­glos­sus and Za­glos­sus. Echid­nas share the order Monotremata with platy­puses, as these are the only ex­tant egg-lay­ing mam­mals. The genus Tachy­glos­sus de­fines the species of short-beaked echid­nas while Za­glos­sus is com­posed of the long-beaked echid­nas. The fam­ily has sim­i­lar mor­pho­log­i­cal char­ac­ters, but long-beaked echid­nas are larger in size, have longer snouts and less spikes than its sis­ter taxa of short-beaked echid­nas. Long-beaked echid­nas are also lo­cated solely in New Guinea, whereas short-beaked echid­nas are found in New Guinea, Aus­tralia, and Tas­ma­nia. The genus of short-beaked echid­nas is com­posed of the sin­gle species T. ac­ulea­tus and its sub­species whereas long-beaked echid­nas have the fol­low­ing three species: Z. at­ten­bor­oughi, Z. bar­toni, and Z. brui­jni. (Burnie and Wil­son, 2011; Cooke, et al., 2008; Nowak, 2018)

Ge­o­graphic Range

Short-beaked echid­nas are dis­trib­uted through­out the en­tire con­ti­nent of Aus­tralia in­clud­ing Tas­ma­nia and east­ern and south­ern New Guinea. Long-beaked echid­nas are en­demic to New Guinea but fos­sil records sug­gest pop­u­la­tions were once in Aus­tralia. (Beer, 2004; Nowak, 2018)

• Biogeographic Regions
• australian
  • native

Habi­tat

Short-beaked echid­nas can have a large range of habi­tats, so long as the sub­strate is suit­able for their bur­row­ing lifestyle. Long-beaked echid­nas have a nar­rower range and are con­fined to New Guinea due to their need for a humid en­vi­ron­ment. Short-beaked echid­nas can sur­vive in more arid en­vi­ron­ments as their diet pro­vides the mois­ture nec­es­sary for sur­vival. Short-beaked echid­nas can in­habit any­where from tem­per­ate or trop­i­cal forests to sandy deserts. Both gen­era of echid­nas have spe­cial­ized feet for dig­ging and bur­row for shel­ter. There has been ev­i­dence of short-beaked echid­nas tem­porar­ily re­sid­ing in aban­doned rab­bit bur­rows for cover. Home ranges of echid­nas is highly vari­able based on their lo­ca­tion, but males' ranges are typ­i­cally twice the size of that of a fe­male’s. Over­lap be­tween ranges of two in­di­vid­u­als may occur, but ter­ri­tory does not lead to hos­til­ity be­tween the two. There is no home den that in­di­vid­u­als con­tinue to re­side in, but nurs­ery bur­rows may be con­structed by fe­males dur­ing re­pro­duc­tion pe­ri­ods. (Beer, 2004; Burnie and Wil­son, 2011; Cooke, et al., 2008; Nowak, 2018)

• Habitat Regions
• temperate
• tropical

• Terrestrial Biomes
• desert or dune
• savanna or grassland
• forest
• rainforest

Sys­tem­atic and Tax­o­nomic His­tory

Echid­nas are clos­est re­lated to platy­puses as they are the egg-lay­ing mam­mals and form the order Monotremata. Monotremes and mar­su­pi­als make up the basal taxa of mam­mals, The­ria- the non-pla­cen­tal mam­mals. Monotremes pro­duce milk, but lack teats. Fos­sil records pro­vide ev­i­dence that mam­mal an­ces­tors dat­ing back to 220 mil­lion years ago were able to suckle based on bone struc­ture and mus­cle at­tach­ment. Monotremes di­verged from the mam­mals around 190 mil­lion years ago and there­fore lost the abil­ity to suckle. It is hy­poth­e­sized the loss of the soft palate to allow for suck­ing oc­curred as an adap­ta­tion to their diet of hard-shelled prey. The genus of short-beaked echid­nas has the fol­low­ing syn­onyms: Acan­thono­tus, Echidna, Echino­pus, Sy­pho­nia. The genus of long-beaked echid­nas has the fol­low­ing syn­onyms: Acan­thoglos­sus, Bruy­nia, Proechidna, Proza­glos­sus. The syn­onyms are a re­sult of names that were once es­tab­lished but are now in­cor­rect due to Prin­ci­ple of Pri­or­ity. (Vogel, 2018; Wil­son and Reeder, 2005)

• Synonyms

  • Acanthonotus
  • Echidna
  • Echinopus
  • Syphonia
  • Acanthoglossus
  • Bruynia
  • Proechidna
  • Prozaglossus

• Synapomorphies

  • Cloaca
  • Oviparious
  • Fur/Hair
  • Mammary Glands
  • 3 inner ear bones

Phys­i­cal De­scrip­tion

Echid­nas lay eggs and are there­fore clas­si­fied as monotremes along with platy­puses, form­ing the basal taxa of mam­mals. Echid­nas are cov­ered in brown or black fur, with spines along the dor­sal side of the body for pro­tec­tion. Short-beaked echidna spines are typ­i­cally yel­low, fad­ing to black at the tip. Long-beaked echid­nas have fewer spines that are white, gray, or black. Short-beaked echid­nas can be 30 to 45 cm in length and weigh from 2.5 to 7 kg, with a beak ap­prox­i­mately half the length of the head and a short tail, typ­i­cally around or under 100 mm. Long-beaked echid­nas are a lit­tle larger from 60 to 100 cm in length and weigh­ing 5 to 10 kg and a beak length rang­ing from 100 mm to 150 mm. This length cre­ates a down­ward curve in their beaks. While echid­nas lack teeth, their ex­tended snouts have pores for elec­trore­cep­tion and sticky tongues to as­sist in achiev­ing a meal. They have short stout legs with long claws for dig­ging. Their hind feet are also pointed back­ward, which gives them an un­usal gait. The hind feet also have a spur on the inner ankle. While in the monotreme platy­pus males have a ven­omous spur, both male and fe­male echid­nas have spurs with­out venom. (Beer, 2004; Burnie and Wil­son, 2011; Cooke, et al., 2008; Nowak, 2018; Ris­miller and Grutzner, 2019)

• Other Physical Features
• endothermic
• homoiothermic
• bilateral symmetry

• Sexual Dimorphism
• sexes alike

Re­pro­duc­tion

Echid­nas are typ­i­cally soli­tary out­side of mat­ing. Males seek out fe­males, and sev­eral fol­low her, form­ing what is col­lo­qui­ally called an "echidna train". Males then bat­tle to for the op­por­tu­nity to mate with the fe­male. (Beer, 2004)

• Mating System
• polygynandrous (promiscuous)

Echid­nas be­come sex­u­ally ma­ture be­tween 5 and 12 years of age. Breed­ing sea­son oc­curs from July to Au­gust. Echid­nas only have one young a year. They have one ex­ter­nal open­ing called a cloaca for ex­pelling waste and re­pro­duc­tion. Males have penises made for only cop­u­la­tion. The penis is bi­fur­cated and forked at the end, giv­ing the males a four-headed penis. Fe­males pro­duce one small, nearly round, leath­ery egg from the cloaca and trans­fer it di­rectly to their pouch where it in­cu­bates for an av­er­age of ten days. Moth­ers pre­pare for hatch­ing in this time by find­ing or dig­ging a bur­row. Ob­ser­vances of cap­tive echid­nas breed­ing in the Perth Zoo demon­strate nearly iden­ti­cal pat­terns to that of re­pro­duc­tion in the wild. (Beer, 2004; Fer­gu­son and Turner, 2013; Nowak, 2018; Ris­miller and Grutzner, 2019)

• Key Reproductive Features
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• oviparous

Male echid­nas do not have parental in­vest­ment so echidna moth­ers pro­vide all care for their off­spring. The young hatch pink and hair­less, weigh­ing only 0.3 g. Baby echid­nas, called pug­gles, re­main in the pouch for around 50 days, where they lap up milk. Echid­nas do not have teats, but rather milk patches where milk sim­ply leaks out. After 50 days, the moth­ers are able to leave the young in a bur­row to for­age for food. They re­turn every 5 to 6 days to feed their off­spring. When moth­ers leave the den, they cover the en­trance with soil to keep their pug­gles safe from pre­da­tion. Young echid­nas be­come in­de­pen­dent at one year old. (Beer, 2004; Nowak, 2018; Ris­miller and Grutzner, 2019)

• Parental Investment
• female parental care

Lifes­pan/Longevity

Monotremes are con­sid­er­ably long-lived. Echid­nas live up to 20 years in the wild and be­tween 30 to 50 years in cap­tiv­ity. (Beer, 2004)

Be­hav­ior

Echidna hind feet ap­pear as if back­wards on their body. This not only helps them to be more ef­fi­cient dig­gers in their fos­so­r­ial lifestyle, but also gives them a unique gait. This is de­scribed as rolling, and can be sim­i­lar imag­ined as wob­bling side to side. The ar­tic­u­la­tion of the hind limb bones also al­lows echid­nas to use their claws for groom­ing. Echid­nas do go into tor­por when they ex­pe­ri­ence food short­ages, de­pen­dent on sea­son and cli­mate. This oc­curs dur­ing the cold sea­son, from April to July. Both body tem­per­a­ture and meta­bolic rate de­crease. Short-beaked echid­nas also enter tor­por dur­ing times of food scarcity but these are short pe­ri­ods based on re­sources, not weather. (Nowak, 2018; Ris­miller and Grutzner, 2019)

• Key Behaviors
• fossorial
• nocturnal
• motile
• sedentary
• aestivation
• solitary

Com­mu­ni­ca­tion and Per­cep­tion

Due to the soli­tary be­hav­ior of echid­nas, com­mu­ni­ca­tion be­tween in­di­vid­u­als is rarely ob­served. Their sen­sory beaks have the po­ten­tial for forms of elec­trore­cep­tion and it has been hy­poth­e­sized they may use vi­bra­tions and re­cep­tion through their beak to com­mu­ni­cate. Vo­cal­iza­tions are char­ac­ter­ized as grunt­ing, oc­cur­ring when an in­di­vid­ual is star­tled. (Beer, 2004)

• Communication Channels
• acoustic

• Other Communication Modes
• vibrations

• Perception Channels
• tactile
• chemical

Food Habits

Echid­nas lack teeth. In­stead they have ker­ati­nous rows of spines on their palate to grind prey. Short-beaked echid­nas have a sticky tongue that can reach up to 180 mm to catch in­ver­te­brate prey. The tongue be­comes sticky from mu­cous se­creted from their sub­lin­gual sali­vary glands. Short-beaked echid­nas eat ants, ter­mites, bee­tles, their eggs and lar­vae, and earth­worms. Short-beaked echid­nas in arid en­vi­ron­ments main­tain water in­take by con­sum­ing only ter­mites. They for­age for in­ver­te­brates by dig­ging and often rip apart rot­ting logs with their claws. (Beer, 2004; Ris­miller and Grutzner, 2019)

Long-beaked echid­nas diets are mainly earth­worms and pos­si­bly other sub­ter­ranean arthro­pods. This lim­it­ing fac­tor is hy­poth­e­sized to be a rea­son for the lim­ited range of this genus. The tongue of long-beaked echid­nas is not sticky and only ex­tends about 2 to 3 cm from their elon­gated snout but they do have rows of ker­ati­nous spines for grind­ing prey. (Beer, 2004; Nowak, 2018)

• Primary Diet
• carnivore
  • insectivore

Pre­da­tion

There are few na­tive preda­tors of short-beaked echid­nas. They are mainly preyed upon by feral pigs, cats, foxes, and dogs. Young echid­nas left in bur­rows can also face goan­nas and snakes. To avoid preda­tors, echid­nas dig and bur­row to hide and leave their spines ex­posed to dis­cour­age an at­tack. Echidna spines work well for pro­tec­tion, but if a preda­tor is able to flip them over to re­veal their soft belly, they are left vul­ner­a­ble prey. (Ris­miller and Grutzner, 2019)

The larger size of long-beaked echid­nas makes them less sus­cep­ti­ble to nat­ural preda­tors. If they do have any, in­stances have not been ob­served often as long-beaked echid­nas live a se­cre­tive life. The biggest threat they face is hu­mans, both from hunt­ing and habi­tat loss. (Nowak, 2018)

• Known Predators

  • red foxes (Vulpes vulpes)
  • domestic cats (Felis catus)
  • domestic pigs (Sus scrofa)
  • humans (Homo sapiens)
  • dingos (Canis lupus dingo)

Ecosys­tem Roles

Short-beaked echidna bur­row­ing habits have pos­i­tive ef­fects on soil mi­cro­biota. Echidna for­ag­ing pits have more en­zy­matic and mi­cro­bial ac­tiv­ity than the sur­face and sub­soil. The pits they dig have more ef­fec­tive mi­cro­bial com­mu­ni­ties and thus are im­por­tant to nu­tri­ent cy­cling in the soil. (El­dridge, et al., 2016)

• Ecosystem Impact
• soil aeration

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Echid­nas are a charis­matic species en­demic to Aus­tralia and pro­vide op­por­tu­ni­ties for eco­tourism. Long-beaked echid­nas are an im­por­tant food source for na­tives. (Darcy, et al., 2010; Nowak, 2018)

• Positive Impacts
• food
• ecotourism

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

There are no known ad­verse ef­fects of echid­nas on hu­mans. (Beer, 2004)

Con­ser­va­tion Sta­tus

Short-beaked echid­nas are listed as least con­cern on the IUCN's red list, but is con­sid­ered en­dan­gered under the Com­mon­wealth of Aus­tralia. Long-beaked echid­nas are listed as Ap­pen­dices II under CITES and crit­i­cally en­dan­gered on the IUCN ex­cept for east­ern long-beaked echid­nas, which are listed as vul­ner­a­ble. Long-beaked echid­nas are at risk due to hu­mans hunt­ing them for food as well as habi­tat loss from the log­ging in­dus­try. (Beer, 2004; Ris­miller and Grutzner, 2019)

• IUCN Red List [Link]

  Not Evaluated

Con­trib­u­tors

Neilee Wil­helm (au­thor), Col­orado State Uni­ver­sity, Tanya Dewey (ed­i­tor), Uni­ver­sity of Michi­gan-Ann Arbor.

Ref­er­ences

Ash­well, K., C. Hard­man, A. Musser. 2014. Brain and be­hav­iour of liv­ing and ex­tinct echid­nas. Zo­ol­ogy, 117: 349-361. Ac­cessed Feb­ru­ary 02, 2020 at DOI: 10.1016/j.​zool.2014.05.002.

Beer, A. 2004. Grz­imek's An­i­mal Life En­cy­clo­pe­dia. De­troit, Michi­gan: Gale. Ac­cessed Feb­ru­ary 02, 2020 at https://​go-gale-com.​ezproxy2.​library.​colostate.​edu/​ps/​i.​do?​id=GALE%7C5ANS&​v=2.​1&​u=coloradosu&​it=aboutBook&​p=GVRL&​sw=w.

Burnie, D., D. Wil­son. 2011. An­i­mal. New York, New York: DK Pub­lish­ing.

Cooke, F., H. Din­gle, S. Hutchin­son, G. McKay, R. Schodde, N. Tait, R. Vogt. 2008. The En­cy­clo­pe­dia of An­i­mals. Berke­ley, Cal­i­for­nia: Uni­ver­sity of Cal­i­for­nia Press.

Darcy, S., B. Cameron, S. Pegg. 2010. Ac­ces­si­ble tourism and sus­tain­abil­ity: a dis­cus­sion and case study. Jour­nal of Sus­tain­able Tourism, 18: 515-537. Ac­cessed March 07, 2020 at DOI: 10.1080/09669581003690668.

El­dridge, D., M. Del­gado-Ba­que­r­izo, J. Wood­house, B. Neilan. 2016. Mam­malian en­gi­neers drive soil mi­cro­bial com­mu­ni­ties and ecosys­tem func­tions across a dis­tur­bance gra­di­ent. Jour­nal of An­i­mal Ecol­ogy, 85: 1636-1646. Ac­cessed Feb­ru­ary 27, 2020 at doi: 10.1111/1365-2656.12574.

Fer­gu­son, A., B. Turner. 2013. Re­pro­duc­tive pa­ra­me­ters and be­hav­iour of cap­tive short-beaked echidna (Tachy­glos­sus ac­ulea­tus acan­thion) at Perth Zoo. Aus­tralian Mam­mal­ogy, 35: 84-92. Ac­cessed Feb­ru­ary 02, 2020 at DOI: 10.1071/AM12022.

Flan­nery, T., C. Groves. 1998. A re­vi­sion of the genus Za­glos­sus (Monotremata, Tachy­glos­si­dae), with de­scrip­tion of new species and sub­species. Mam­malia, 62: 367-396. Ac­cessed Feb­ru­ary 02, 2020 at https://​doi-org.​ezproxy2.​library.​colostate.​edu/​10.​1515/​mamm.​1998.​62.​3.​367.​.

Grif­fiths, M. 1968. Echid­nas. N.S.W. Aus­tralia: Perg­a­mon Press.

Nowak, R. 2018. Walker's Mam­mals of the World. Bal­ti­more, Mary­land: John Hop­kins Uni­ver­sity Press. Ac­cessed Feb­ru­ary 02, 2020 at https://​ebookcentral.​proquest.​com/​lib/​csu/​reader.​action?​docID=5108357&​ppg=11.

Ris­miller, P., F. Grutzner. 2019. Tachy­glos­sus ac­ulea­tus. Mam­malian Species, 51(980): 75-91.

Vogel, G. 2018. Echid­nas don't suck-but their an­ces­tors did. Sci­ence, 361: 213. Ac­cessed Feb­ru­ary 02, 2020 at DOI: 10.1126/sci­ence.361.6399.213.

Wil­son, D., D. Reeder. 2005. Mam­mal Species of the World. John Hop­kins Uni­ver­sity: John Hop­kins Uni­ver­sity Press. Ac­cessed March 09, 2020 at https://​www.​departments.​bucknell.​edu/​biology/​resources/​msw3/​.