One of the most iconic images of shark behavior is a great white shark hitting its prey so hard from below that the whole shark flies out of the water. This behavior, called “breaching,” has been documented in many species, and is useful for a variety of ecological functions, not just hunting. I spoke to authors of a new review paper about this incredible phenomenon.
Figure 1 from Klimley et al. 2024. Caption reads: Breaching behaviors by common thresher (Alopias vulpinus) (a), pelagic thresher shark (Alopias pelagicus) (b), bull shark (Carcharhinus leucas) (c), shortfin mako shark (Isurus oxyrinchus) (d), white shark (Carcharhinus carcharias) (e), salmon shark (Lamna ditropis) (f), blacktip shark (Carcharhinus limbatus) (g), bronze whaler shark (Carcharhinus brachyurus) (h), and basking shark (Cetorhinus maximus) (i). The photographers, email addresses, dates, and locations and dates of the filmed breaches are given in Appendix 1
“Breaching occurs when an aquatic animal propels itself entirely out of the water and into the air, landing forcefully on the surface and causing a significant splash as it displaces the water upon impact,” Dr. Alison Kock, a marine biologist with South African National Parks and a coauthor on the recent study, told me. “The breaching behaviour of sharks has always fascinated me. The first time I saw a great white shark was when it launched itself entirely out of the air, chasing after a Cape fur seal at Seal Island, False Bay, Cape Town. The sight of the massive shark in the air with gaping jaws and the sound of the splash when it landed, is etched in my mind. I knew at that moment that I wanted to spend the rest of my life studying these powerful and incredible predators. Since that moment, more than 26 years ago, I have observed the behaviour 1000s times with great whites.”
Dr. Tobey Curtis, a shark scientist who works for NOAA Fisheries and a coauthor on this study, told me that “the coolest thing about seeing sharks breach is that it’s usually so unpredictable. You can stare at the surface of the water for hours or days and not see anything. And then all of a sudden there’s this big animal hanging above the horizon, and by the time your brain computes what you’re looking at, there’s a thunderous explosion of water. Even for experienced field researchers who have seen lots of cool things on the water, it can be a jaw-dropping event. It’s absolutely spectacular behavior to witness up close.”
Prior to this review paper, breaching in sharks and rays had been noted in the literature, but usually as brief anecdotal natural history observations. The global team of experts wanted to create a one-stop-shop, summarizing and synthesizing everything known about this type of behavior to identify gaps in knowledge that can shape future research directions.
Dr. Kock pointed out that lots of marine animals engage in some kind of breaching behavior, including whales, dolphins, seals, and many species of bony fish. And, like sharks and rays, they do it for many different reasons. “What amazed me was how widespread breaching is among different shark and ray species and the various reasons behind it,” Dr. Kock told me. “We discovered that at least 19 species breach to remove external parasites, 4 to clear their gills, and another 4 to expel faeces or internal parasites. For feeding, 10 species used breaching to chase prey, while 8 did it to concentrate or stun prey. In communication, at least 8 species breached during courtship chases, 6 to attract others, and 1 to repel them. Breaching also appears to be an escape tactic, with 14 species using it to escape predators. Lastly, we recorded at least 4 species breaching and expelling pups during birth! Female manta rays, devil rays, and eagle rays leap out of the water to give birth, with the pressure from landing thought to help release their large pups!” The paper includes a list of links for people to view YouTube and Instagram videos of many of these behaviors.
“The first surprise to me was how many species from widely divergent taxa have been documented to breach,” Dr. Curtis told me, noting that he personally had seen many species breach while on research expeditions. “We all know about white sharks breaching to capture seals, but why would a filter-feeding manta ray expend so much energy to jump out of the water? The second surprise was that after all of the team’s efforts, we still don’t know why most shark and ray species breach. We collated a number of hypotheses, but at the end of the day we’re mostly still just making informed guesses.”
The paper closes with a thoughtful and thorough list of suggestions on how future researchers can test these hypotheses, and hopes that the increasingly widespread availability of high quality cameras among oceangoers means more anecdotal observations will keep pouring in. And by working together, as this team of experts did, we can help to put these puzzle pieces together and learn something about these incredible animals.