The family 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)consists of two genera of echidnas,
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)
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)
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)
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)
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)
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)
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)
Monotremes are considerably long-lived. Echidnas live up to 20 years in the wild and between 30 to 50 years in captivity. (Beer, 2004)
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)
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)
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)
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)
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)
There are no known adverse effects of echidnas on humans. (Beer, 2004)
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)
Neilee Wilhelm (author), Colorado State University, Tanya Dewey (editor), University of Michigan-Ann Arbor.
Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.
uses sound to communicate
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.
an animal that mainly eats meat
uses smells or other chemicals to communicate
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.
humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.
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.
parental care is carried out by females
A substance that provides both nutrients and energy to a living thing.
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
Referring to a burrowing life-style or behavior, specialized for digging or burrowing.
An animal that eats mainly insects or spiders.
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
active during the night
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
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.
breeding is confined to a particular season
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
digs and breaks up soil so air and water can get in
uses touch to communicate
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).
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
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.
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.
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.
movements of a hard surface that are produced by animals as signals to others
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