While often portrayed as solitary hunters, sharks can exhibit complex social behaviors, sometimes gathering in groups. Understanding when and why they come together offers insights into their lives. The most recognized term for a group of sharks addresses this intriguing aspect of their existence.
The Primary Name
The most commonly accepted term for a group of sharks is a “shiver.” This unique term can imply the chilling sight of these predators moving together, or refer to a trembling motion as they move through the water. Certain species, such as scalloped hammerheads, are frequently observed forming large shivers, particularly during specific times of the year, demonstrating this collective behavior.
Nurse sharks, often found resting in crevices or under ledges, also occasionally form shivers. These aggregations can be observed in their natural habitats, where multiple individuals might gather in a relatively confined space. The term “shiver” particularly applies to these more static or loosely associated groupings, reflecting a less coordinated movement.
Other Grouping Terms
While “shiver” is prevalent, other terms describe shark groups based on their specific behaviors. A “school” of sharks refers to a more organized and coordinated grouping, often observed during migration or when sharks are feeding on abundant prey. This term applies to species that exhibit highly synchronized movements, similar to how many schooling fish behave. For instance, smaller pelagic sharks might form schools when traversing open ocean expanses.
A “pack” of sharks, in contrast, implies a group engaged in coordinated hunting or feeding. This term suggests a more active and potentially aggressive collective behavior, where individuals might work together to corner or overwhelm prey. Oceanic white-tip sharks, known for their opportunistic feeding habits, have been observed forming packs around food sources, demonstrating this cooperative approach. Reef sharks sometimes exhibit pack-like behaviors when targeting specific prey in their coral reef environments.
Why Sharks Form Groups
Sharks form groups for various biological and behavioral reasons, which depend on the species and environmental conditions.
One significant reason is hunting or foraging efficiency, where a group can increase the chances of capturing prey. Some shark species might encircle schools of fish, making it easier for individuals within the group to feed. This collective strategy can lead to a higher success rate than solitary hunting.
Mating is another primary driver for shark aggregations. Many species gather in specific locations during breeding seasons, forming temporary groups for reproductive purposes. These aggregations facilitate the finding of mates and the successful continuation of their species.
Sharks also group for migration, particularly for long-distance travel. Large aggregations can be seen moving together, possibly benefiting from reduced energy expenditure due to hydrodynamic effects or for navigational purposes. Scalloped hammerheads are a prime example, forming massive schools during their seasonal migrations, often following warm currents or prey movements.
Protection, though less common for apex predators, can be a factor for smaller or juvenile sharks. Grouping can offer some defense against larger predators, as there is safety in numbers. Smaller species or younger individuals might benefit from the collective vigilance and confusion that a group can create, making it harder for a predator to single out an individual.