Zaglossus bartoni

Geographic Range

Eastern long-beaked echidnas are found east of the Paniai Lakes region of New Guinea. They are found in the Central Cordillera (the central highlands) and in the Huon Peninsula, both mountain ranges in New Guinea. Though they have a relatively wide distribution across New Guinea, they are sparsely populated throughout much of this range. Population estimates are not known.

• Biogeographic Regions
• australian australian
  • native native

• Other Geographic Terms
• island endemic island endemic

Habitat

Eastern long-beaked echidnas have an expansive altitudinal range from sea level to 4150 meters. Their habitat is generally limited to the cooler, mountain summits of New Guinea. They inhabit tropical montane forests and sub-alpine and alpine grasslands. Montane rainforests (1000 to 3000 m) are rich in wildlife and thick with trees. At higher elevations, in the sub-alpine and alpine grasslands (3000 m or higher), there is less diversity of flora and fauna. Eastern long-beaked echidnas live in burrows underground or in dense vegetation. When underground, the dens are covered with little vegetation and are usually found on slopes because it is easier for Z. bartoni to dig into them.

• Habitat Regions
• tropical tropical
• terrestrial terrestrial

• Terrestrial Biomes
• savanna or grassland savanna or grassland
• forest forest
• rainforest rainforest
• mountains mountains

Physical Description

Eastern long-beaked echidnas are the largest living monotremes, usually weighing from 5 to 10 kilograms. They have long, dense black to dark brown fur and white spines that cover the entire dorsal surface of their body. Their spines can sometimes be obscured behind long fur. They have long, tubular rostra with an average length of 12.3 centimeters. Eastern long-beaked echidnas do not have teeth but they have a horny plate at the back of their mouth to help grind food. Both males and females have a cloaca: a single orifice for the passing of feces, urine, and eggs (in females) (Augee et al., 2006; Flannery and Groves, 1998). Eastern long-beaked echidnas are heterothermic endotherms; they depend on movement and shivering as a source of body heat. The lowest body temperature of a captive population was measured at 24.2 degrees Celsius. The highest body temperature was 34.2 degrees Celsius. The average body temperature of captive populations was in the low 30's. The basal metabolic rate was recorded at 24.41 kJ/hour (Grigg, 2003; McNab, 2008). Adults differ from the juvenile Z. bartoni in a variety of features. In the transition to adulthood, the sutures of the cranial bones close completely, the major basicranial foramina stay open but narrow with age, the rostrum lengthens, the posterior palate bones become more robust, and the narial opening becomes shorter and rounded posteriorly (Flannery and Groves, 1998). The presence of a spur sheath in Z. bartoni is indicative of a juvenile (Opiang, 2009; Rismiller, 1999).

The main morphological distinction between western long-beaked echidnas ( Zaglossus bruijni ) and eastern long-beaked echidnas is the difference in claw number on the forefoot. Eastern long-beaked echidnas have five claws on each forefoot, whereas western long-beaked echidnas have three to four claws on each forefoot, usually lacking claws on digits one and five. Cranial features also differ between the two species. The braincase of eastern long-beaked echidnas is as high as it is long, whereas western long-beaked echidnas never have braincases as high as they are long. Eastern long-beaked echidnas have smaller orbitotemporal fossae than western long-beaked echidnas and the posterior end of the palate is flattened in eastern long-beaked echidnas, but is a channel in western long-beaked echidnas . Eastern long-beaked echidnas usually have a cranium with a dorsal depression that lies between the rostrum and the braincase. Western long-beaked echidnas lack this feature. However, some eastern long-beaked echidnas lack the depression as well, so this feature is not diagnostic (Flannery and Groves, 1998).

There are four recognized subspecies, which exhibit substantial geographic variation. These subspecies are Z. bartoni bartoni , Z. bartoni clunius , Z. bartoni smeenki , and Z. bartoni diamondi . The subspecies differ in size, fur coloration/density, and geography. Based on cranial measurements, the smallest subspecies is Z. bartoni smeenki and the largest is Z. bartoni diamondi (Flannery and Groves, 1998). In terms of sexual dimorphism, males possess a spur on their ankle, which is lacking in females. This is often used for sex determination. However, some juvenile females possess the spur. Females are often larger than males, but there is not a significant difference in size. Female eastern long-beaked echidnas have significantly longer snouts than males (Opiang 2009).

• Other Physical Features
• endothermic endothermic
• heterothermic heterothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• female larger
• sexes shaped differently
• ornamentation ornamentation

Reproduction

Monotremes lack external genitalia; therefore an investigation of the cloaca and/or palpation of the penial sack is necessary for a robust verification of sex. When breeding, male penises protrude from the cloaca, which is seen as a sign of sexual activity. It has been suggested that Z. bartoni is reproductively active in April and May since females have been found lactating during these months. The mating system is not reported.

Due to the solitary and obscure nature of eastern long-beaked echidnas, details about their reproduction are not well known. However, according to researchers and native New Guinean people its reproduction is similar to that of western long-beaked echidnas and short-beaked echidnas ( Tachyglossus species). Native people have said they give birth to one echidna at a time, which would be consistent with western long-beaked echidnas accounts. Since they have similar reproduction, it can be inferred that breeding is seasonal (April/May). Females lay the eggs and the eggs hatch around 10 days later. Juveniles stay in the female’s pouch for another 6 to 7 weeks until the spines grow in and the young are weaned after around seven months.

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

Eastern long-beaked echidna females nurse and wean their young. Like other monotremes, mothers nurse young through pores connected to their mammary glands since they do not have nipples.

• Parental Investment
• altricial altricial
• female parental care female parental care
• 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 is 30 years in captivity at the London Zoo. There is no doubt this species is particularly long-lived, especially for its size. A lifespan of 30 years is around double the lifespan that would be expected based on the body size of Z. bartoni .

Behavior

Eastern long-beaked echidnas are nocturnal, terrestrial, and create underground dens. The burrows made by Z. bartoni in parts of Crater Mountain Wildlife Management Area are generally a mix of dens made in dense vegetation and dens made underground. This is an example of direct competition with conspecifics because of the dense population in this area. Generally eastern long-beaked echidnas avoid other echidnas and are solitary. This solitary nature makes it harder for researchers to find and study their behavior. Studies of captive Z. bartoni found that they do not exhibit long, deep torpor, which has led researchers to believe that hibernation is unlikely in the wild.

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

Home Range

The home range for Z. bartoni is estimated to be 10 to 168 hectares with a mean of 39 hectares. Home range size for Z. bartoni is not associated with body mass, age, or sex, but with food availability.

Communication and Perception

The skin on the outside of the rostrum has a large number of electroreceptors (around 2000), which allow it to detect electrical signals to better locate their prey in the wet soil during the night (Map of Life, 2012). There is no available information on communication between Z. bartoni individuals.

• Perception Channels
• visual visual
• tactile tactile
• chemical chemical

Food Habits

Eastern long-beaked echidnas are insectivores that forage at night and eat mostly earthworms and occasionally grubs.They have several adaptations for foraging, including a long snout and relatively large claws on the forefeet. They have a specific tongue adaptation for grabbing earthworms. There are three rows of sharp, spine-like structures at the back of its tongue, which enables them to more effectively grasp earthworms while foraging. The foraging method for obtaining grubs consists of tearing open logs with their claws to find the grubs and other “wood-boring” invertebrates. They dig for earthworms by using the combined effort of their snout and forelimbs. The method they use is called a “head press,” which is a probing technique in which they apply pressure to the wet soil, mostly from their long snout and partially from their forelimbs. The depression made by the head press creates a hole, which can be used to find earthworms. This foraging depression is larger and deeper than the one made by the short-beaked echidna.

• Primary Diet
• carnivore carnivore
  • insectivore insectivore
  • vermivore

• Animal Foods
• insects
• terrestrial non-insect arthropods
• terrestrial worms

Predation

The building of an underground den is a measure of predator avoidance in Z. bartoni . Risk of predation and human hunting is lowere because these animals are elusive and cryptic. Another adaptation for defense from predators is their spines. This provides an armored exterior as protection from predation. Thylacinus is an extinct genus of carnivorous mammal, the Tasmanian wolf, that lived in the mountains of Papua New Guinea until the Holocene. They may have been a native predator when they co-occurred. Today there are no known native predators of Z. bartoni . However, feral domestic dogs Canis lupus familiaris , introduced a few thousand years ago, are known to occasionally prey on Z. bartoni and humans sometimes hunt them.

• Anti-predator Adaptations
• cryptic cryptic

Ecosystem Roles

Eastern long-beaked echidnas have similar ecology to species such as Phalanger carmelitae , Pseudochirops corinnae , Uromys anak , and Anisomys imitator . These are all medium-sized mammals living in mid-upper montane regions. This suggests that they are filling the same insectivorous, medium-sized mammal niche. The foraging depressions they create could become resource traps. In turn, this could affect soil biochemistry and nutrient circulation. Though there are no known ectoparasites for Z. bartoni , there are several known for Tachyglossus , and Z. bartoni may be carriers for these as well. Some of these parasites include fleas from the genera Echidnophaga , Pulex , Bradiopsylla , Stephanocircus , and ticks from the genera Aponomma , Ixodes , Haemaphysalis , and Amblyomma .

• Ecosystem Impact
• soil aeration soil aeration

Economic Importance for Humans: Positive

Eastern long-beaked echidnas are hunted as a highly valued game species for native people in New Guinea due to its rarity and general inaccessibility. Their meat is considered a delicacy and echidna bodies can serve as “trophies” to native people.

• Positive Impacts
• food food
• body parts are source of valuable material

Economic Importance for Humans: Negative

There are no known adverse effects of Z. bartoni on humans since their habitat is in areas with low population density.

Conservation Status

As of 2011, the IUCN listed Zaglossus bartoni as a Critically Endangered species. This species is also listed on Appendix II of CITES. Population size has decreased by 80% over the last 45 to 50 years based on direct observation of their habitat. Though Z. bartoni lacks local native animal predators, the population is decreasing due to hunting and loss of habitat from the conversion of their habitat into agricultural land. Conservation management for Z. bartoni has been difficult due to the limited information on the ecology and breeding patterns of this species. The Papua New Guinea Institute of Biological Research has started a long-term conservation research project, headed by Muse Opiang. The goal is to illuminate the reproduction, ecology, and natural history of this species.

Other Comments

Zaglossus bartoni was not considered a separate species until 1998 when Flannery and Groves published their paper establishing it as distinct from Zaglossus bruijni based on geographic location and morphology (Flannery and Groves, 1998). Fossil echidnas found in Australia and New Guinea date back to the Pleistocene and are very similar to living species (Griffiths et al., 1991).

Additional Links

Encyclopedia of Life

Contributors

Peter Flynn (author), Yale University, Eric Sargis (editor), Yale University, Rachel Racicot (editor), Yale University, Tanya Dewey (editor), University of Michigan-Ann Arbor.

References

Augee, M., B. Gooden, A. Musser. 2006. Echidna: Extraordinary Egg-Laying Mammal. Echidna: Extraordinary Egg-Laying Mammal . Australia: CSIRO.

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 and Biochemistry , 39: 1055-1065.

Flannery, T., C. Groves. 1998. A revision of the genus Zaglossus (Monotremata, Tachyglossidae), with description of new species and subspecies.Mammalia. Mammalia , 62: 367.

Griffiths, M., R. Wells, D. Barrie. 1991. Observations on the skulls of fossil and extant echidnas (Monotremata: Tachyglossidae). Australian Mammalogy , 14: 87-101.

Grigg, G. 2003. Body temperature in captive long-beaked echidnas (Zaglossus bartoni). Comparative Biochemistry and Physiology. Comparative Biochemistry and Physiology a-Molecular & Integrative Physiology , 136: 911.

Helgen, K., M. Opiang, W. Thomas. 2011. The mammal fauna of Wanakipa, Southern Highlands Province, Papua New Guinea. RAP Bulletin of Biological Assessment , 60: 246.

Helgen, K. 2007. The mammal fauna of the Kaijende Highlands, Enga Province, Papua New Guinea. RAP Bulletin of Biological Assessment , 45: 52.

Jackson, S. 2003. Australian Mammals: Biology of Captive Management . Australia: CSIRO Publishing.

Leary, T., L. Seri, T. Flannery, D. Wright, S. Hamilton, K. Helgen, R. Singadan, J. Menzies, A. Allison, R. James, K. Aplin, L. Salas, C. Dickman. 2011. "Zaglossus bartoni IUCN Red List of Threatened Species" (On-line). IUCN. Accessed April 12, 2012 at www.iucnredlist.org .

McNab, B. 2008. An analysis of the factors that influence the level and scaling of mammalian BMR. Comparative Biochemistry and Physiology a-Molecular & Integrative Physiology , 151: 5-28.

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

Opiang, M. 2009. Home ranges, movement, and den use in long-beaked echidnas, Zaglossus Bartoni, from Papua New Guinea. Journal of Mammalogy , 90: 340-346.

Rismiller, P., M. McKelvey. 2000. Frequency of breeding and recruitment in the short-beaked echidna, Tachyglossus aculeatus. Journal of Mammalogy , 81: 1.

Rismiller, P. 1999. The echidna—Australia’s enigma . Hong Kong: Hugh Lauter Levin Associates.

2012. "Central Range Montane Rain Forests" (On-line). WWF Scientific Report. Accessed April 10, 2012 at http://www.worldwildlife.org/science/wildfinder/ .

2012. "Electroreception in fish, amphibians and monotremes" (On-line). Map of Life. Accessed April 10, 2012 at http://www.mapoflife.org/topics/topic_41_Electroreception-in-fish-amphibians-and-monotremes/ .