Army Helicopters Flying Overhead Cause a Sex Frenzy Among Australian Crocodiles

Army helicopters flying overhead at Queensland farm spark a sex frenzy among crocodiles

• Chinook helicopters are arousing crocodiles
• Electrical storms have also affected mating season
• READ MORE: Fisherman's 'stupid' crocodile encounter

Army helicopters flying at a low range coupled with fierce electrical storms are causing an odd sex frenzy among crocodiles on a rural farm. 

John Lever, owner of The Koorana Crocodile Farm near Rockhampton in Queensland, noticed that his crocodiles have been especially fertile since Singaporean Chinook helicopters began flying over his farm. 

Experts are trying to understand why the helicopters, combined with recent electrical storms, are having such a significant impact on crocodile mating season. 

But professors from the University of Queensland and Darwin University are at odds about what exactly is the cause of the amorous activity.

Leading theories point towards crocodiles mistaking the reverberations from helicopters as mating calls and changes in biometric pressure as explanations. 

Singaporean Chinook helicopters (pictured) are causing crocodiles at Rockhampton's Koorana Crocodile Farm in Queensland to begin mating early 

Recent electrical storms and a warmer than average winter had also helped create perfect breeding conditions for crocodiles (pictured), owner of the farm John Lever said

Dr Cameron Baker, who specialises in the ecology, behaviour and social structure of the estuarine crocodile at Darwin University, thinks that male crocodiles are mistaking the distinct thuds of the Chinook as mating calls from competing crocs. 

'It might be producing a very low-frequency "thump, thump" as it hits the water. That may just coincidentally be similar to some of the sounds big male crocodiles produce to say, "Hey, this is my turf",' Dr Baker told ABC.

READ MORE: Female crocodile's 'virgin birth'

Zookeepers discovered that an 18-year-old female American Crocodile, an apex predator growing up to 20ft, was guarding a clutch of 14 eggs in her enclosure, despite not having seen a male in over a decade.

The Singapore Armed Forces have been holding bilateral military training operations in the Shoalwater Bay Training Area about 100 kilometres north of Rockhampton since 2020. 

Officers flying the Chinook helicopters use the Koorana Crocodile Farm as a marker point to change course mid-flight. 

Mr Lever said that every time they pass over it elicits the same response, and he also believes it has something to do with their thumping sound. 

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

After the Chinook left Mr Lever said that his crocodiles quickly began mating. 

Crocodile mating season spans from September to April in North Queensland which coincides with the wet season, sparking another theory from Dr Barker. 

'They're probably using (Chinooks) as a bit of a cue to say, "Hey, the wet's coming" … and it's a good time to start mating so the eggs are ready to be laid at just the right time,' Dr Baker said. 

This year Mr Lever said that an especially warm winter coupled with early-September thunderstorms have created the perfect mating conditions.

Crocodiles usually vocalise to each other when they are ready to mate, according to Mr Lever. 

Because they do not have sophisticated voice boxes, the reptiles simply vibrate their windpipes to send messages through the water. 

The added vibrations of electrical storms and low-flying helicopters help make the most out of mating season, which only lasts a matter of minutes. 

Dr Cameron Baker (pictured), a crocodile specialist at Darwin University, believes that crocodiles might be mistaking the sound of helicopters for mating calls from other crocs

The thumping sounds of the Chinooks are similar to the guttural calls of crocodiles looking for a mate

Professor Craig Franklin, who specialises in Zoology at the University of Queensland, said that crocodiles mate during storms because of a change in barometric pressure. 

'We don't know what happens in farms, but our research shows that in the field they respond to rainfall events … and of course, they're often associated with a change in barometric pressure,' Professor Franklin said.

'These would all be signals that the crocodile relies upon to time its breeding activity.'

The Koorana Crocodile Farm produces roughly 2,000 eggs per year, of which 1,200 result in a hatchling. 

Droughts and dry summers like the ones seen in 2020 can drastically reduce these numbers, which heavily impacts the profitability of the farm.

The farm faced six years of El Nino conditions in the 1990s, but the Bureau of Meteorology announcing that El Nino would hit this year does not seem to have impacted this season's production forecasts. 

Severe thunderstorms hit coastal Queensland at the beginning of September and unpredictable weather conditions have continued since then. 

Chinook helicopters are also a staple of this time of year since Australia signed a military training treaty with Singapore which has led to 14,000 Singapore armed forces personnel operating in the area. 

The treaty allows Singaporean troops to participate in unilateral training in the region for up to 18 weeks a year for the next 25 years. 

https://www.dailymail.co.uk/news/article-12586375/Army-helicopters-flying-overhead-Queensland-farm-spark-sex-frenzy-crocodiles.html