Rarest egg-laying mammal

The world’s rarest species of monotreme, or egg-laying mammal, is Attenborough’s long-beaked echidna (Zaglossus attenboroughi). Named after veteran British naturalist Sir David Attenborough, it was for many decades known from just a single specimen, found dead on a mountain in Papua, Indonesia, in 1961, now housed in the archives of Naturalis Biodiversity Center natural history museum in Leiden, the Netherlands. However, in November 2023, video footage was released of a living specimen recorded at night by a camera trap during an expedition to Papua's little-explored Cyclops Mountains. The multi-national expedition was led by biologist Dr James Kempton of Oxford University (UK).

Local hunters have reported seeing other living specimens for many years, but this is the first Attenborough’s long-beaked echidna ever caught on camera.

In total, there are four living species of echidna; along with the platypus, they comprise the entire order of extant monotremes (Monotremata). The short-beaked echidna (Tachyglossus aculeatus) of Australia and New Guinea is deemed of Least Concern by the IUCN and the eastern long-beaked echidna (Z. bartoni) of New Guinea is classed as Vulnerable. The western long-beaked echidna (Z. bruijnii), also of New Guinea, though restricted to the Vogelkop Peninsula and the adjacent island of Salawati, is listed as Critically Endangered (like Z. attenboroughi) but recent local anecdotal evidence indicates this species is still sighted relatively frequently, particularly in the rainy season (Jan-Apr).

The echidna was not the only highlight of the expedition to the Cyclops Mountains: the scientists also recorded a number of new insect and frog species, yet to be formally described.