2 Egg-Laying Mammals Living Down Under: Part 1 (Echidna)

All mammals give birth to live young right? Well, not quite. Mammals are divided into two subclasses based on their reproductive systems: ‘monotremes’ (egg-laying mammals) and ‘therians’ (mammals which give birth to live young). ONLY five egg-laying mammal species currently exist on our planet, one platypus species and four echidna species. In Australia we have two species, the ‘Platypus’ and the ‘Short-beaked Echidna’. The other three are the Long-beaked Echidna species found in New Guinea.

While there are many cool stuff about these weird and wonderful creatures, I have decided to list a Top 5 about our local aussies: the Short-beaked Echidna and the Platypus. This week we shall enjoy reading about the Short-beaked Echidna and  next week, we shall visit the curious looking Platypus 🙂

Short-beaked echidna (Tachyglossus aculeatus)

Short-beaked Echidna
Short-beaked Echidna

Echidnas are widely distributed in a variety of landscapes throughout Australia. These light brown spiny animals are quiet, extremely shy and tend to keep to themselves making it hard to spot them in the wild. The echidnas over in Tasmania are much darker, almost black in colour. They weigh between 2 to 7 kg and love feasting on ants and termites. After a successful mating season, a female lays a single soft and leathery egg, and incubates it in her pouch which takes about ten days to hatch.

In the past, the only way I had spotted them was when I heard some scratches coming from the shrubs or behind some rocks, or when a brave one decided to cross a busy country highway for reasons unknown. Sadly, echidnas crossing the highways sometimes end up as roadkill. Seeing any roadkill is hard enough, but seeing an echidna roadkill always evokes strong reactions from me (crying mostly). I simply love them with all my heart. This is why for so many years and for many more to come, whenever I go bushwalking, the first sentence which departs my lips will always be, “Oh my gosh, I hope to see an echidna today!”.

Without further ado, here are the TOP 5 COOL Echidna facts:

(1) Echidnas use electroreceptors to detect living things

In addition to their keen sense of smell, Short-beaked Echidnas have 400 electroreceptors concentrated on the tip of their snout. This helps them to detect the electromagnetic signals emitted by living things (electrolocation) such as ants and termites giving them a good tummy full of feed. The Western Long-beaked Echidna  has about 2000 electroreceptors on its snout. Electroreceptors are quite exclusive to aquatic animals such as sharks as water acts as a great signal conductor, making this land dwelling mammal an exception (other exceptions include bees and cockroaches).

Searching for some feed on a rotting log
Searching for some food on a rotting log

(2) No nipples here!

Yes, echidnas have NO nipples. The female echidna secretes milk from milk patches found within her pouch. The milk is secreted from up to 150 pores onto special hair follicles which is then happily consumed by the puggle (baby echidna).

Echidna puggle
Echidna puggle – Such a precious looking thing.

(3) Hop on the love train

Forget a one male one female courtship rituals! During an echidna’s breeding season, a train of up to 10 males is formed behind a single female. Males line up nose to tail forming the train which can last up to a month or more. During this time, male echidnas can hop off or on in the line anytime they want. Of course, the one who persevere the longest is most likely to stay ahead of the game. When the female becomes receptive, the males dig a trench around her, then begins some jostling action for the ultimate mating right!

(4) One opening does it all

The cloaca is a single opening in an echidna serving multiple purposes. Through this one opening, echidnas urinate, defecate, lay eggs and receive sperm. This anatomical feature is common in reptiles and amphibians.

(5) Echidnas have a four-headed penis

I saved the best for last of course 🙂 Before I started writing this, I had NO idea about this. Male echidnas possess a four-headed penis. Each head extends like a stumpy finger with no nails. I saw some pictures of it and to me it looks like a shiny pink heart valve of sorts. It was strange and fascinating at the same time, if this makes any sense at all! It is believed that this gives them a competitive edge during mating season due to the high competition with so many males lining up for one female. Apparently only two of the penis heads function at any one time, while the other two tuck away waiting for their turn. I also found out that the male’s sperm travels in a bundle (like a pack) making it travel much faster, thus increasing the chances of his offspring making it to the next generation. These facts bring mating competition to a completely different level! Phew!

For further information and pictures about the echidna’s reproductive organ, click here

Did you know?

Unlike the ‘least concern’ conservation status of the Short-beaked Echidna in Australia, all three of the Long-beaked Echidna species found in New Guinea have been listed as ‘critically endangered’ in the IUCN Red list due to severe habitat loss and hunting (for meat).

Western Long-beaked Echidna
Western Long-beaked Echidna

I hope you enjoyed reading this! Till next week for top 5 cool facts on the Platypus. I shall leave you with this really nice short clip about echidnas which I found.

Photo credits:
Short-beaked Echidna: David Cook Wildlife Photography / FoterCC BY-NC
Echidna foraging around log: cskk / Foter / CC BY-NC-ND
Puggle: ibsut / Foter / CC BY-NC-SA
Header: Nuytsia@Tas / Foter / CC BY-NC-SA

Video Credit: NatGeoWild channel on youtube.

One thought on “2 Egg-Laying Mammals Living Down Under: Part 1 (Echidna)

  1. Pingback: 2 Egg-Laying Mammals Living Down Under: Part 2 (Platypus) | Conservation for the Wild

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