Woman's 'pink dolphin' discovery comes undone after tiny detail spotted in photograph

While Ruby hadn't spotted a rare 'pink dolphin' like she first thought, she did however capture something just as interesting.

Left - Broken Head, NSW. Right - close up of the
It was initially believed a pink dolphin had been spotted at Kings Beach, Broken Head. Source: Ruby Pearson

Looking across the heads at a tranquil Aussie beach on the weekend, a local woman spotted what she thought was a rare pink dolphin.

Pulling out her camera, Ruby Pearson snapped a series of images showing the bottlenose dolphin frolicking with a regular grey coloured "friend" in waters south of Byron Bay.

“I was born and raised in Byron, and I've seen a lot of dolphins. But I've never seen a pink dolphin,” she told Yahoo News on Monday night.

A day earlier, Pearson had excitedly shared her pictures to an online animal identification forum. "We thought one of the dolphins looks pink? Is this just an illusion? A trick of the light? Is there such a thing?," she asked others.

But respondents quickly shot down any thought Pearson had encountered a dolphin with a strange colour mutation. But, as it turns out, there was one salacious detail she didn't notice in the moment.

What she’d spotted was just the animal's undercarriage, which contrasts with their grey backs — an attribute designed to help them camouflage against the bright sky when predators look up. But that begged the question: Why was the dolphin upside down?

Looking closely at one of the images, Pearson got her answer.

“At the time, we didn’t know what we were seeing. There was lots of splashing and jumping going on. And I said to my friend I was surprised they aren’t riding any of the waves,” she recalled.

“They were just hanging in the one spot, and my friend said it looks like they’re feeding because they’re definitely distracted by something.

“But when we looked at the photos we could see there was actually sexual activity going on.”

Three images of the
Looking closer at the photos it became clear Ruby had been looking at the underside of a dolphin who was mating with a female. Source: Ruby Pearson

Dr Vanessa Pirotta, a wildlife scientist and science communicator, confirmed it was even possible to see the dolphin’s penis in one of the pictures.

Although a dolphin’s penis is highly manoeuvrable, couples will often try different positions in the water to increase their chances of reproducing.

“Males may mate with multiple females and in a variety of positions in order to reproduce,” she said.

“Generally, the male will bring his body to meet the female, this may involve the male swimming upside down. The dolphin’s close proximity to shore enabled this sighting of behaviour probably not seen before by these spectators.”

Related: How male lyrebirds trick females into having more sex

While the photos may not show a pink dolphin, they actually capture something that's just as fascinating – the usually hidden world of marine mammal reproduction.

Pearson's photos were published online the same day a male harbour porpoise was photographed in Alaska as it breached from the water while trying to mate with a female.

Their larger whale cousins are also well-known for their unique reproductive systems.

Pirotta's new book, Humpback Highway, includes a chapter on how whales mate and use song to communicate. One of the most fascinating facts she’s included is that humpbacks have the largest testicles in the animal kingdom. They weigh an astonishing 500kg each, so one tonne in total!

Meanwhile right whales have a penis that can extend to three metres in length.

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