Cane Toads, Assisted Migration

We are all aware that the introduced Cane Toad (Bufo marinus), is a spreading plague across the face of Australia, wiping out many native species in its path, (that is those who mistake it for food, like Quolls, Goannas, Black Snakes, Kookaburras etc.).

“102 toads were collected from Hawaii, and brought to Australia. After an initial release in August 1935, the Commonwealth Department of Health decided to ban future introductions until a study was conducted into the feeding habits of the toad. The study was completed in 1936 and the ban lifted, at which point large scale releases were undertaken—by March, 1937, 62,000 toadlets had been released into the wild.” wikipedia.org/wiki/Cane_toad.

What many may not know is that the common Eastern Water Dragon (Physignathus lesueurii), isan unwilling transport slave to this South American Pest.

Eastern Water Dragons characteristically arise each morning and take a dip in the pool or billabong near which they have spent the night. They sit in the water, near the bank or a rock, sothat their body is submersed and their heads sit just above the level of the water, as seen below.

The mating habits of cane toads are such that the males congregate at night fall around ponds and pools, and upon spotting a female, they climb onto her back and then wrapping their front legs around her, just behind the neck under the arm pits, hang on until she release her eggs. He then fertilises them externally. This is a common form of mating among amphibians, and is known as Amplexus.

Unfortunately for the Eastern Water Dragon, as it sits with its head above the water, just on dawn, having its early morning ablutions in the shallows near the waters edge, it looks for all the world to randy Cane Toads, like a very attractive object of romance. The Cane Toads swim up behind the Water Dragon, drive the pads of their forearms in behind the head of the Water Dragon, and wait for love to unfold. The Water Dragon however wants to exit stage right at this point, and takes its infatuated passenger on its morning foraging journeys.

This has been observed on more than twenty occasions in the hinterland of Byron Bay northern NSW, as depicted by the following photos, and one must ask the question, is this assisting in the migration of Cane Toads, or are these cross species antics rehearsals for some bizarre Sci-Fi flick where Cane Toads, riding Water Dragons, attempt to take over the habitats of Australia.

The Romance Begins

Hanging on whilst on the run

Unrequited Love

Lovers Bliss

Hanging on around corners

Loves Resignation

Chris Lonergan 10/02/10 Cape Vista Dr Ewingsdale

clonergan@designevolutions.com.au