Behaviour

Orcas and humpbacks brawl

Whale watchers were making their way toward the U.S.-Canadian border in the Strait of Juan de Fuca when the captain spotted the group of whales. At first, whale watchers observed what they thought was a pod of roughly 15 Bigg’s orcas swimming and "being unusually active at the surface." Before long, it became apparent that two humpback whales were in their midst.

Intense

According to observers who came and went throughout the day, the intense encounter that unfolded included an astonishing three hours of breaching, tail-slapping and loud vocalizations.

Dolphin BFFs?
Dolphin BFFs?

Male dolphins form lifelong bonds

Researchers have discovered that male bottleneck dolphins form long-term social groups to help one another find mates and fight off competitors.

It was the first time such behaviour was observed in the animal world.

Their conclusions were based on data collected of 202 Indo-Pacific bottlenose dolphins between 2001 and 2006 in Shark Bay, Australia, using visual and auditory data. In the lab, the researchers then focused on studying the interactions of 121 of individuals for the next decade.

Seeking Eye Contact: Fish Gaze Reveals Self-Awareness

For many years, I held a weekly feeding session for the resident reef sharks and their visitors in the study area where I observed their behaviour. If I had enough shark food, I would scatter crumbs into the water for the fish after the sharks had left. The fish knew this, so they had to wait, and while they were waiting, they were excited.

Octopus at Curacao
Octopus on reef, Curacao

Octopuses’ arms can detect light

In general, the cephalopod’s sense of where its body is in space is quite poor, so this complex instinctive behavior may act to protect the arms from undetected predators nearby, which may mistake the tips of the octopus’s arms as fish or worms.

That octopus arms react to light has long been known. Its skin is covered in chromatophores, pigment-filled organs that change color when light falls upon them. They are behind the octopus’s color-changing camouflage ability.

There is evidence that white sharks form non-random social associations and may remain in proximity to each other to take advantage of pinniped kills.

Great white sharks have a secret social life

Florida International University (FIU) marine scientist Yannis Papastamatiou, Ph.D. candidate Sarah Luongo, and a collaborative team of researchers wanted to uncover some of the mysteries of the white sharks (Carcharodon carcharias) that gather seasonally around Guadalupe Island, Mexico. 

Sperm whale.  Photo by Eric Cheng
Will humans ever understand what these cetaceans are saying?

Will we learn to speak whale?

Project CETI is a nonprofit organisation applying machine learning and robotics to listen to and translate the communication of whales. The organisation is working to develop a deeper understanding of the complex system of communication that sperm whales use and share this understanding with the world.

Why do fish rub themselves against a shark?

Fish rubbing themselves against a shark's body may sound as if they have a death wish, but this is precisely what some fish have been spotted doing. And it turns out that such behaviour is more widespread and frequent than one would think.

A study led by the University of Miami (UM) Shark Research and Conservation Program at the Rosenstiel School of Marine and Atmospheric Science uncovered over 40 instances of fish rubbing themselves against a shark’s skin in over ten locations around the globe.

While chafing has been well documented between fish and inanimate objects, such as sand or rocky substrate, this shark-chaffing phenomenon appears to be the only scenario in nature where prey actively seek out and rub up against a predator.

Surfers are the highest-risk group for fatal shark bites, especially by juvenile white sharks
Surfers are the highest-risk group for fatal shark bites, especially by juvenile white sharks

"Mistaken identity theory" behind shark bites put to the test

Why sharks sometimes bite humans remains unclear, but potential reasons include mistaken identity, whereby sharks are thought to mistake humans for their typical prey; curiosity; hunger; and defensive/offensive aggression.

The mistaken identity theory has received little scientific scrutiny and the visual similarity between humans and pinnipeds at the surface has been debated largely on the basis of human visual perception, rather than that of sharks.

Whale watching off Iceland
Whale watching off Iceland

Do Tourist Boats Stress Out Whales?

Do whale watchers bother whales? A number of studies on tourism's impact on whales, which were based on behavioural observations, have concluded that tourism caused only minor disruptions to the mammals. 

For example, in 2015, a study led by Marianne H. Rasmussen, director of the University of Iceland Húsavík Research Centre, found that whale watching as currently practised does not seem to be having any long-term negative effects on the life expectancy of minke whales.