Echidna: Reproduction

Summary: Making baby echidnas is weird! Join Kiersten as she talks echidna baby-making.

 

For my hearing impaired listeners, a complete transcript of this podcast follows the show notes on Podbean

 

Show Notes: 

“Echidna penises: Why They’re so Weird,” by Angela Heathcote, Australian Geographic, May 24, 2021. https://www.australiangeographic.com.au

“Echidna trains: Explained,” by Australian Geographic, August 6, 2021. https://www.australiangeographic.com.au

“Getting out of a mammalian egg: the egg tooth and caruncle of the echidna,” by Jane C. Fenelon, Abbie Bennetts, Neal Anthill, Micheal Pyne, Stephen D. Johnston, Alistair R. Evans, Abigail S. Tucker, and Marilyn B. Renfree. Developmental Biology, Volume 495, March 2023, pg 8-18.

“Unveiling the echidna pouch: Insights from recent research.” The Wildlife Preservation Society of Queensland. https://wildlife.org.au

Classification of Living Things: Echidna Reproduction, by Denis O’Neil. https://www.palomar.edu

Music written and performed by Katherine Camp

 

Transcript 

(Piano music plays)

Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife.

(Piano music stops)

Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. 

This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it.

This episode continues echidnas and the fourth thing I like about them is how they reproduce. I have to tell ya that this is the best episode yet! Be prepared to have your mind blown because echidna reproduction is unbelievable.

Reproduction always starts with the wooing, so let’s start there, as well. You can always tell when echidna mating season is by the lines of males that are following a female. No kidding, male echidnas form “love trains” behind a female and follow her for days. I have found several different sources that say mating can occur anywhere from mid-May to early September. Males will follow a female around until they are the last one standing. Love trains can vary in number from 4 males to 11 males. The males will follow the females jostling each other, sometimes even pushing each other into ditches, to be the last male following the female. 

Once they’ve joined a love train the males are very focused on what they’re doing. Very few things can distract them from their goal of mating, including being weighed by scientists. Peggy Rismiller has studied echidnas for 30 years and she has picked up the last male in a love train to weigh them and, as soon as she puts them down, they are off again following the female.

Males will travel long distances to court a female. She tracked one male who traveled 2 km or 1.2 miles a day to court two different females. If the male looses sight of the female he’s courting, no worries, he can follow her scent. Both males and females emit a musky scent during breeding season. 

After a male has outlasted the others, if the female is receptive, she’ll lay down on the ground and relax her spines. But his hard work is not done. Now the male has to dig down into the soil next to the female so he can line up their cloacas. Mating is performed cloaca to cloaca. Once the positioning is just right, the male will insert his penis into the female’s cloaca. Copulation can last from 30 minutes to an hour and a half.

We’re going to take a moment to talk about the echidna penis because this particular organ has been deemed the weirdest reproductive organ in the animal kingdom by Smithsonian Magazine. An echidna’s penis is bright red in color and has four heads. Yes, you heard correctly, four heads. They do not use their penis for urination, like most other mammals, so the penis was able to become more elaborate. It appears that they only use two of the heads at a time when breeding. This is very unusual for mammals but it is see in some reptiles. More research needs to be done to understand how the echidna penis works and why it is structured the way it is. The penis is also fairly long reaching approximately 1/3 of the echidnas body length when erect. 

Stay with me listeners because it just keeps getting weirder. Once the female is pregnant she develops a pouch. Only pregnant female echidnas develop a pouch, and they only keep it while they are incubating their single egg. There are four stages of the pouch. Dr. Kate Dutton-Regester has been researching echidna pouches and took over 200 pictures of nine female echidna’s developing pouches. At the beginning of the breeding season the pouch is flat and difficult to see, by the time the female needs to incubate her egg the pouch margins have drawn together like a drawstring bag closing the pouch so incubation can begin. Once her offspring has left the pouch, it recedes over 12-30 days until it is once again flat. That is truly amazing!! 

Next step: lay an egg. Echidna females lay only one egg a year, or at least as far as we know. The egg is 1/2 to 2/3 of an inch long. The shell is like hard leather, similar to some reptile eggs. The egg is laid through the cloaca, then the mother has to get it into her pouch. To do this, she’ll curve her body into a tight “C” shape scooping up the egg with the tops of her hind feet and then lifting up her feet until the egg rolls into the pouch. 

Whoosh! I’m tired just thinking of doing that. Talk about good core strength. The egg will incubate for approximately 10 days before it hatches. Echidna eggs have much less yolk than reptile and bird eggs because the embryo only needs that nutrient source for 10 days. To emerge from the egg, the embryo develops and egg tooth similar to an egg tooth on a baby reptile. This egg tooth helps the young echidna break out of the leathery egg shell, then disappears. Baby echidnas are called puggles. That is literally the cutest name I have ever heard for any animal offspring. I just can’t right now!

The puggle is only the size of a raisin when it hatches and is hairless and blind. The tiny puggle will grasp the coarse hair inside the pouch and pull itself up to the milk patches inside the pouch. While puggles are in the pouch they consume milk produced by the mother’s mammary glands. They do not suckle because echidnas have no nipples, so instead they lick the milk as it seeps through the skin over the mammary glands. Puggles will remain in the pouch for approximately 45 days until they begin to develop spines. That could be a sticky situation.

Once they leave the pouch, the puggle will remain in a den for 6 to 7 months. During that time, mom will leave to forage for food and come back to feed the puggle milk. At 7 months, the puggle is old enough to strike out on its own. Echidnas can live from 15 to 40 years, but average about 10 years in the wild.  

 

  I don’t know about you, but this was one weird reproduction episode, but it is definitely my fourth favorite thing about echidnas. 

 

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Join me next week for another episode about echidnas.    

 

(Piano Music plays) 

This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.