The long-beaked echidnas (genus Zaglossus) make up one of the two extant genera of echidnas: there are three extant species, all living in New Guinea.[2][3] They are medium-sized, solitary mammals covered with coarse hair and spines made of keratin. They have short, strong limbs with large claws, and are powerful diggers. They forage in leaf litter on the forest floor, eating earthworms and insects.
Attenborough's long-beaked echidna (Z. attenboroughi), discovered by Western science in 1961 (described in 1998) and preferring a still higher habitat;
The Eastern species is listed as vulnerable, while the Attenborough's and western long-beaked echidna species are listed as Critically Endangered by the IUCN.[4][5][6]
A number of extinct species were known in the genus, but they are currently treated as members of their own genera, such as Murrayglossus and Megalibgwilia.
General information
The long-beaked echidna is larger-bodied than the short-beaked and has fewer, shorter spines scattered among its coarse hairs. The snout is two-thirds of the head's length and curves slightly downward. There are five digits on both hind and forefeet, but on the former, only the three middle toes are equipped with claws. Like the other species of echidna, long-beaked echidnas have spurs on their hind legs. These spurs are vestigial; part of a repressed venom system akin to the one on the platypus. Male spurs are nonfunctional and females usually lose their spurs as they age.[7]
Basal traits
The breeding female develops a temporary abdominal brood patch, in which her egg is incubated and in which the newborn young (or puggle) remains in safety as it feeds and develops. Since they reproduce by laying eggs which are incubated outside of the mother's body it is accompanied by the prototherian lactation process, which shows that they are basal mammals. The long-beaked echidna has a short weaning period. During this time milk is their only source of nutrition and protection for the hatchlings; they are altricial and immunologically naive.[8]
The long-beaked echidna's limb posture is sprawled, similar to extant reptiles like lizards and crocodilians. Although the stances between the animal groups are similar, the way the limbs move are very different between the clades. The echidna swings its limbs at a 45 degree angle while a lizard's is more horizontal. They walk with two legs on one side of the body moving in unison.[9]
The long-beaked echidna's walk presents multiple differences from a lizard's. An echidna's walking pattern is more upright than a lizard's, this represents a pattern closer to a parasagittal kind of therian. Echidnas and therians both have a dynamic equilibration rather than a static one. [10]
Behavior
These echidnas are primarily nocturnal; foraging for its insect food on the forest floor. These animals are not usually found foraging in the daylight. The long-beaked echidna establish and are commonly found in dens or burrows.[11]
A study published in 2015 shows that Zaglossus spp. in captivity exhibited "handedness" when performing certain behaviors related to foraging, locomotion, and male-female interactions. The results of this study suggest that handedness in mammals is a basal trait rather than one derived several times in extant mammals.[12]
Little is known about the life of these rarely seen animals, but it is believed to have habits similar to those of the short-beaked echidna; unlike them, however, the long-beaked echidnas feed primarily on earthworms rather than ants, as they live in much more humid environments than the smaller Tachyglossus echidna. The population of echidnas in New Guinea is declining because of forest clearing and overhunting, and the animal is much in need of protection. In November 2023, a Zaglossus attenboroughi was first recorded alive on video in Indonesia's Cyclops Mountains, the first confirmed sightings of an individual in 62 years.[13]
Taxonomy
Cladogram of Zaglossus by Upham et al. 2019[14][15]
^Werneburg, I.; Sánchez-Villagra, M. R. (January 2011). "The early development of the echidna, Tachyglossus aculeatus (Mammalia: Monotremata), and patterns of mammalian development". Acta Zoologica. 92: 75–88. doi:10.1111/j.1463-6395.2009.00447.x.
^ abLeary, T.; Seri, L.; Flannery, T.; Wright, D.; Hamilton, S.; Helgen, K.; Singadan, R.; Menzies, J.; Allison, A.; James, R.; Aplin, K.; Salas, L.; Dickman, C. (2016). "Zaglossus bartoni". IUCN Red List of Threatened Species. 2016: e.T136552A21964496. doi:10.2305/IUCN.UK.2016-2.RLTS.T136552A21964496.en. Retrieved 12 November 2021. Database entry includes justification for why this species is listed as critically endangered.
^ abLeary, T.; Seri, L.; Flannery, T.; Wright, D.; Hamilton, S.; Helgen, K.; Singadan, R.; Menzies, J.; Allison, A.; James, R.; Aplin, K.; Salas, L.; Dickman, C. (2016). "Zaglossus bruijnii". IUCN Red List of Threatened Species. 2016: e.T23179A21964204. doi:10.2305/IUCN.UK.2016-2.RLTS.T23179A21964204.en. Retrieved 12 November 2021. Database entry includes justification for why this species is listed as critically endangered
^Gambaryan, P. P.; Kuznetsov, A. N. (2013). "An evolutionary perspective on the walking gait of the long-beaked echidna". Journal of Zoology. 290 (1): 58–67. doi:10.1111/jzo.12014. ISSN1469-7998.
^Gambaryan, P. P., & Kuznetsov, A. N. (2013). An evolutionary perspective on the walking gait of the long-beaked echidna. Journal of Zoology, 290(1), 58–67. https://doi.org/10.1111/jzo.12014
