A Chinook helicopter got more than it bargained for when it swooped down low to take pictures of some captive crocodiles, as it accidentally triggered a giant orgy. Exactly what it is about low-flying helicopters that gets crocodiles in the mood isn’t known for certain, but it appears to mimic one of the natural cues these animals use to know when it’s time to get it on.

The ecrocic scenes unfolded at Koorana Crocodile Farm in Central Queensland which sits close to the Shoalwater Bay Training Area in Rockhampton, meaning the captive animals often see aircraft. In what’s arguably the most eloquent piece ever written about a crocodile sex party heralded in by chinooks, farm owner John Lever told ABC Far North that a particularly low-flying helicopter had a rousing effect on the animals.

"We had a big Chinook that came down low because the guys wanted to take some pictures of the crocodiles," said Lever. "They were hanging out the door … and of course, Chinooks have got a big thump, thump, thump, like that."

"All of the big males got up and roared and bellowed up at the sky, and then after the helicopters left they mated like mad.”

A similar effect, though not quite so potent, is seen when storms roll into Australia, which figures as these animals are supposed to mate during the rainy season. Storms could be a cue that optimal egg conditions are on the horizon, but what good is a chinook helicopter for crocodile hatchlings?

Crocodiles are highly vocal and use sounds to signify “This is my turf,” “Would anyone like a shag,” and “I am baby” (there’s actually a weird link between crocodiles and human babies’ vocalizations, too).  One possible explanation is that the sound of the chinook is getting confused for the sounds bulls make when they want to mate, getting everyone riled up and in the mood.

Alternatively, low-frequency sounds could be perceived similarly to the rolling storms that also seem to act as an aphrodisiac for crocodiles. That the chinook flying particularly low down may have enhanced this normally more subtle cue, perhaps explaining why everything kicked off with such vigor.

With Australia headed for the wet season, it seems there’ll be plenty more croc shenanigans to come.

"We've had a lovely warm winter," Lever continued. "We've actually had a thunderstorm already, which is an aphrodisiac for a croc – it really turns them on … and we've had some rain. So, it's on."