New research has found that the geographical barrier of the Cobourg Peninsula has the ability to stop relocated crocs from migrating back to their site of capture.
The findings are a revelation given that crocs, through their refined homing ability, usually manage to successfuly make their way back to their original abode, which makes it difficult for authorities to enhance the safety of certain areas and minimise human-croc conflict.
What you might call the fun element of the study involved equipping salties with satellite trackers and observing their behaviour. Lead researcher Mr Yusuke Fukuda explained the process and the significance of the findings:
“Five males (3.03m to 4.02m) were shifted and released 100 to 300 kilometres from their capture sites and three others (3.67m to 4.23m) were released at their site of capture as controls,” Fukuda says.
“The translocated salties were highly mobile relative to the controls, and moved at sea in the direction of their original capture site.
“However, they were unable or unwilling to swim around a geographic structure, Cobourg Peninsula, which prevented homing being achieved in all five cases.
“This is in contrast to what happens in Queensland, where Cape York is not an effective barrier to crocodile movement, at least for the larger salties.
“This suggests that the more than 250 crocodiles the NT Government removes each year from the Darwin Harbour for public safety come from the western side of the Peninsula,” Fukuda added.
Researchers were able to corroborate the implications of the findings with genetic analyses of tissue samples from nests across the NT coast. The study received support from the NT Government and various universities, as well as from other groups.