Mexico. Isla Mujeres. Sailfish sardine run
Each year during the winter season, nutrient rich currents flow from South America pushing its way north up onto the shallow shelf off of Isla Mujeres, Mexico drawing in large schools of sardines. Following these baitfish are great numbers of Atlantic sailfish (scientific name: Istiophorus albicans).
It is here in these shallow waters that marine life and predators collide in havoc. Locating the sailfish and sardines can take a combination of a few ingredients: lots of patience, persistence, years of experience, and one last ingredient: frigate birds (scientific name: Fregata Magnificens) swirling in a funnel cloud formation. Approaching their location the water surface looks like it is boiling from all the sardines breaking the surface.
The sailfish cooperate as a team to hold the bait ball together. Every time the bait ball changes direction it encounters another sailfish: that sailfish will through up it's sail-like dorsal fin to scare the bait ball into diverting in another direction. The sailfish herd the bait ball near the surface and try not to let it sink down deep or disperse.
When the bait ball gets close to the surface the frigate birds dive down grapping and gulping sardines, which pushes the mass down into a tighter bait ball. This team of sailfish are not all feeding at the same time: their method is to take turns individually going after the bait ball with astounding speed and precision maneuverability slashing the dense bait ball blindly with their bills knocking hapless individuals unconscious or wounding them enough to separate them from the safety of the bait ball. The isolated sardines are consumed within seconds on a second incredibly fast turn and pass by the sailfish. The next sailfish with a good position has its turn and the cycle starts again. The whole process continues unless the sardines perform enough evasive maneuvers to loose the sailfish or the predators are full and loose interest.
It is truly an amazing experience watching the sailfish work together as a team using precision, accuracy, and teamwork to control the bait ball, then demolish it.