Three thousand crocodiles mate like crazy! It turns out that it was because of the helicopter

In Queensland, Australia, a Chinook helicopter descended slowly with a low roar. Below was a crocodile farm , where about 3,000 saltwater crocodiles lived. The helicopter pilot took the farm as a landmark, turned a corner here, and also let the passengers take some good photos.

"As the helicopter flew lower and lower, all the big male crocodiles raised their upper bodies, roared and roared towards the sky. After the helicopter flew away, they began to mate like crazy ," said farmer John Lever.

There are no videos or photos here, so readers are left to their imagination.

Why do crocodiles feel so compelled by the appearance of helicopters? Is this a moral decline or a distortion of crocodile nature? Welcome to watch this episode of "Nature from the Fruit Shell".

Male saltwater crocodile (Crocodylus porosus) | Molly Ebersold, St. Augustine Alligator Farm, Wikipedia

Heavy rain is coming

Let's start with the protagonist of this story - the saltwater crocodile. This is the largest species of crocodile . Adult males can easily grow to 6 meters long and weigh more than a ton, but females are usually no longer than 3 meters. They are typical opportunists and eat all kinds of animals they can beat , even buffalo.

Saltwater crocodiles are distributed from Southeast Asia to northern Australia. Their life rhythm is closely related to rain . They usually spend the rainy season in freshwater swamps and migrate to estuaries and offshore during the dry season.

The life rhythm of saltwater crocodiles is closely related to rain｜Rohan Coghlan

In order to ensure that their offspring are born in better weather conditions and avoid strong winds, rainstorms and swollen rivers, saltwater crocodiles will court and mate when heavy rains come . Then, after another 4 to 6 weeks, the female will lay eggs, which will then take about three months to hatch the baby crocodiles.

In northern Australia, October is a breeding season for crocodiles, but such a dramatic scene is rare. British zoologist Mark O'Shea told Live Science that the crocodiles may have interpreted the noise and vibrations from the helicopter as a sign that a storm was coming .

CH-47 Chinook helicopter, a medium transport aircraft | Pixabay

Crocodiles' "sixth sense"

Crocodiles have well-developed integumentary sensory organs (ISO), which are mainly distributed on their jaws and skin, and can sense water flow, air pressure and low-frequency sound waves. Normally, these organs can help them perceive the surrounding environmental information and the movements of prey , allowing them to move freely in turbid water. When the breeding season arrives, ISO allows them to keenly perceive changes in the weather .

"The downdraft from such a large, heavy helicopter would have caused a change in ambient air pressure, which the crocodile would have been able to sense through the ISO on its skin," O'Shea said. " The downdraft caused a drop in air pressure, which may have been similar to the pressure changes that occur before a storm ."

Scales on crocodile skin | Pixabay

Another possibility is that the helicopters produced infrasound , low-frequency sound waves that are imperceptible to the human ear. To the crocodiles, the noise might have sounded like the thunder before a storm or the low growls of males courting mates.

It’s probably hard for humans to imagine what it feels like to be able to detect changes in air pressure or low-frequency vibrations, or to get aroused by the arrival of a helicopter. But in fact, humans share a set of structures that sense touch with crocodiles and many other creatures: Merkel cells .

Merkel cells are important structures that make up the sensory organs of crocodiles' epidermis, and they are also present in all seven classes of vertebrates. Mice rely on the sense of touch of their whiskers and paws to detect the environment. Some birds rely on the sense of touch of their beaks to find food in the mud. In humans, Merkel cells are spread all over the skin, with the highest density in the mouth, hands and genitals . It allows us to feel the taste of food, the caress of a lover, or... the vibration of a sex toy.

When you think about it this way, there isn't much difference between humans and crocodiles.

References

[1] Jacklin Kwan. 'They mated like mad': Low-flying helicopter sparks massive crocodile orgy in Australia. LiveScience. https://www.livescience.com/animals/alligators-crocodiles/they-mated-like-mad-low-flying-helicopter-sparks-massive-crocodile-orgy-in-australia. 2023-10-10/2023-10-25.

[2] Chris Calcino and Adam Stephen. Crocodile sex frenzy triggered by Chinook helicopters and thunder in central Queensland. ABC News. https://www.abc.net.au/news/2023-10-01/croc-sex-frenzy-rockhampton-chinook-helicopter-aphrodisiac/102914902. 2023-10-01/2023-10-25.

[3] Saltwater crocodile. Wikipedia. https://en.wikipedia.org/wiki/Saltwater_crocodile. 2023-10-25.

[4] Reproduction. Crocodile Specialist Group. http://www.iucncsg.org/pages/Reproduction.html. 2023-10-25.

[5] Liu Xia, Wang Siyi, Rui Chen, et al. Tissue distribution of Merkel cells in multiple species[J]. Life Science Research, 2023, 27(3): 253-266.

Author: Maya Blue

Editor: Little Towel, Mai Mai

Image source: Molly Ebersold, St. Augustine Alligator Farm, Wikipedia