Talking Frogs With Mike Tyler
Mike Tyler – affectionately known as ‘The Frog Man’ – is a herpetological hero. He is the recipient of numerous awards, has published more than 400 scientific papers and 24 books, and has edited or co-edited another 11 books and journals. Among his many contributions to herpetology, he has described 69 new frog species or genera and reported the first fossil frogs from Australia and New Guinea. His most recent book is Field Guide to the Frogs of Australia, Second Edition.
Throughout much of the world, frog populations are declining, with the survival of many species under threat. So to celebrate World Frog Day on 20 March and raise awareness for these amazing amphibians, we asked Mike to share with us what he finds so fascinating about frogs.
As a child I enjoyed keeping tadpoles and watching them slowly turn into frogs. I had been told that the tadpole tail drops off during the transformation, but I was able to report my observation that the tail is totally absorbed into the body. Waste not, want not! Although I could not spell ‘absorbed’, I knew what it meant!
Not all frogs have a tadpole stage. Many species lay just ten or so eggs and the babies develop as miniature frogs inside the egg capsule. Some species lay thousands of eggs in vast clumps which float on the surface of the water like blobs of detergent. When the eggs have developed into tadpoles, they just fall off and, after a couple of days, swim away and start feeding. If you find frogs living in your garden, you can feed them boiled lettuce leaves, such as the outside leaves that people usually discard.
When the tadpoles lose their tails and become baby frogs (froglets), they are at great risk of drying out. To help them through this difficult period, it is a good idea to put flat stones or bark near the froglet’s water home so that they can have a safe shelter.
With over 8000 different kinds of frogs throughout the world to choose from, my favourite is one that I found in Australia. In the Kimberley, northwest of WA, in the company of some friends, I was peering through the windscreen of a truck whilst it was pouring with rain. Frogs were hopping all over the road, but I spotted one that was different. It was a large green tree frog, and the feature that set it apart from the others was a large gland on its head and large sulphur spots on its back. This was unlike any frog that I had seen before.
Back in my laboratory, I chose the name Litoria (now Pelodryas) splendida, now commonly known as the Magnificent or Splendid Tree Frog.
The glands on the head have excited the chemists at the University of Adelaide. Because there is no way I would kill this beautiful creature to obtain the liquid secretions the gland contains, I developed a technique involving the application of a weak electrical current to the skin over the gland. This causes the muscles in the gland to contract and squeeze out the contents which can be washed off and thus collected. Previously, chemists had needed to kill the frog to obtain the glandular secretions. They would remove the skin, dry it in the sun and then extract the chemicals with a solvent.
The Magnificent Tree Frog lived up to its name by having antibiotics in its gland. The more common Green Tree Frog of northern Australia also has antibiotics in its gland. How else could it live in a toilet without getting an infection?
We hope that you can take the time to celebrate the beauty, diversity and hidden marvels of our amazing Australian native frogs on World Frog Day – and every day!
And if you’re looking for more ribbiting reading, check out Mike Tyler’s most recent book, Field Guide to the Frogs of Australia, Second Edition (published March 2020). It contains species accounts for Australia’s 248 known native frog species, as well as the introduced Cane Toad and nine ‘stowaway’ species.
The field guide is beautifully illustrated throughout by renowned wildlife artist Frank Knight, whose images we have used in this blog. You can find out more about this book on our website.