MISSION

We will be heading to the outback of the Northern Territory and Western Australia to catch freshwater crocodiles to analyse and compare their resistance to invasive cane toads.

A freshwater crocodile gnawing on a giant cane toad

Photo: Mike Letnic

BACKGROUND

Cane toads have had a devastating impact on Australia's native species. They are toxic at all life stages (from egg spawn to tadpole to adult toad) and have caused population declines in bird, frog, mammal, and reptile populations. The cane toad 'invasion' front is advancing at an alarming rate (about 55 km a year!) so native populations currently unaffected will be hit in the near future. 

Can we do anything to help them? 

That's where you come in. With your help we can locate cane toad resistance in populations behind the invasion front, and thus we may be able to help populations that have yet to be hit.

OUTLINE

Like many of Australia’s native species, freshwater crocodile populations plummeted after the introduction of the cane toad. However, after spending some time in the Northern Territory and Western Australia, Professor Mike Letnic and collaborators noticed that some populations had stabilised despite the continued presence of cane toads. What remained a mystery was how crocodiles were surviving in a cane toad infested area. Freshwater crocodiles are still eating cane toads, but now they appear to have developed some form of resistance to the toxin. Our team intends to find out WHAT the resistance is and also HOW effective this method is at reducing toad susceptibility. 

In this project we aim to compare a population of toad-exposed freshwater crocodiles in the Northern Territory, with a toad-free population of crocodiles in Western Australia, ahead of the cane toad invasion. Our specific aims are to compare: a) food preferences, b) behaviour, c) physical attributes, d) toxin susceptibility, and e) genetic resistance, of juvenile crocodiles from the two populations. If our hypotheses are correct this could be one of the first examples of cane toad resistance in an Australian species. This research will inform attempts to preempt the cane toad front, thus reducing the impacts of cane toad arrival in unexposed species, not just the freshwater crocodile.

HOW?

We will compare two populations using the same methods. One population will be toad-exposed (Victoria River: exposed since 2002-2005) and one population will be ahead of the invasion (Fitzroy River) with no (or limited) toad exposure.

We will be sampling during the dry season when the river falls and becomes a number of accessible water holes. We will conduct a food preference and behaviour comparison at a number of these waterholes (Test 1). On the following nights we will collect juveniles for a detailed behavioural, physical, and toxin susceptibility comparison (Tests 2 & 3). We will also collect a small scale (or 'scute') for genetic analysis (Test 4). While we run these tests we'll be keeping our friendly crocs in heated portable pools before releasing them back into the wild. This is to keep our crocs happy, healthy, and safe while they're in our care.

Our research has been approved by the UNSW Animal Care and Ethics Committee (2019). Approval number #19/30B.

If you would like to name one of our juvenile crocs please consider sponsoring a crocodile ($50 or $100 reward tier). We'll send you a photo of your croc as well as a description so you can keep your scaly friend close to your heart. This is a perfect gift idea as well.

A juvenile freshie on the riverbank

Photo: Aly Ross

WHO WE ARE

We are a team of three female scientists passionate about conservation and wildlife research. We are avid adventurers who enjoy getting out in the wild and seeing parts of Australia that aren’t often seen. We spend a lot of time in the bush and our tents are almost a second home! We want to combine our love of the outback with our passion for saving Australia's awesome native wildlife. There are still crocodile populations that haven’t been hit by the cane toad invasion, and if our project can give them a fighting chance we need to do everything we can to make it happen.

The Team:

Aly Ross: Lead Investi-Gator

Aly is working on her PhD thesis studying the effects of naivete on Australian native species, and how we can combat it.

Tahneal Hawke

Tahneal is finishing her PhD thesis studying platypus population dynamics.

Charlotte Mills

Charlotte is finishing her PhD thesis studying arid zone ecology and predator-prey interactions.

Tahneal and Aly with platypus scientists in 2017

Photo: Aly Ross

Other photos:

Banner photo: Jasmine  Vink

Reward photo 1: EcoPrint

Reward photo 2: Carl Bento

Reward photo 3: Jasmine Vink

Read more about the toad invasion affecting crocs here

We are lucky enough to have most of the equipment for our project donated or loaned to us from various sources. We only need a relatively small amount for essentials to get this project up and running. As of April 5th we have met our initial goal of $2100!! We are now aiming for $4000 which will allow us to visit extra sites and get some important equipment!

Meeting our goal of $4000 will allow us to buy:

ALREADY FUNDED:

$1400 Car fuel

$100 Boat fuel

$200 Croc pools

$400 Heaters

ADDITIONAL FUNDING:

$300 Spotlights ($150 each)

$500 Generator hire (to charge the spotlights and water heaters)

$200 Solar panel (An eco-friendly alternative)

$800 Car fuel for new sites

$100 Boat and generator fuel

= $4000 total!