How drones are being used to lure, catch crocs

WILDLIFE officers have started deploying drones with bait dangled from the end as a quicker, safer method to catch crocs.

Department of Environment and Science senior wildlife officer Matt Brien said the technique was developed in 2019 as part of research into improved methods to capture crocodiles.

"This direct capture method takes advantage of the crocodile's instinctive predatory response to grab anything it sees moving at the water's surface," he said.

Department of Environment and Science wildlife officers have been developing techniques for using drones to catch crocodiles. A drone skimming bait to lure a croc.

"Using a drone, wildlife officers skim a baited noose along the water's surface near the target crocodile.

"When the crocodile grabs the moving bait and attempts to eat it, the noose locks on to the animal's top jaw and the rope is released from the drone.

"The drone is flown back to its launch point and a float attached to rope allows wildlife officers on a boat to find the rope and retrieve the crocodile.

A croc jumps for the bait dangled by a drone.

"Wildlife officers have already used this novel approach to 'direct-capture' a problem crocodile from Innisfail's Johnstone River in August 2019, and the whole process took about 15 minutes."

Dr Brien said this is the first innovation in crocodilian capture methods to be developed in decades.

"Previously, the standard methods used to capture estuarine crocodiles were restricted to the use of baited traps, nooses, harpoons and stationary baited lines," he said.

"While those methods have been effective, the drone technique provides another option for wildlife officers to rapidly capture crocodiles, while minimising any harm or injury to the animal.

"Inspections of the top jaws of crocodiles captured during the research program showed the noose caused the animals no abrasions or bruising.

"This new capture method provides researchers and wildlife managers with an innovative, nonlethal, humane and efficient way of removing wary and hard-to-capture crocodiles from the wild."