Abstract
The whale shark population of Bahía de Los Ángeles (BDLA) has recently been shown to feed on dense schools of anchovies in the presence of other predators, and these observations coincide with other reports of whale sharks feeding on nektonic baitfish prey in other geographic areas. An investigation into the whale shark population of BDLA using an aerial drone was conducted in order to observe this population and note close encounters and behaviors around schools of baitfish and in the presence of other marine predators. This project generated unique drone footage of a lone whale shark pursuing a baitfish school with eventual intervention by a brown pelican, as well as an observation of a fish school possibly filling the water with gametes that a whale shark then fed on . These and other drone observations were compiled alongside evidence of whale sharks closely associating with baitfish and other marine life throughout their global range through video, anecdontal, and publicized reports. Evidence of whale sharks closely associating with or preying upon baitfish in 21 different locations was found, and among these locations the Azores and Nosy Be emerged as areas with the most frequent reported whale shark and baitfish interactions, likely due to focused and widespread observations as part of other studies. This data set includes six confirmed prey species of baitfish that whale sharks have been recorded consuming, as well as 41 species of marine predators that have been seen associating with whale sharks near baitfish schools. Predatory fish like tuna were the most commonly observed, but seabirds and marine mammals were frequently seen as well. The evidence compiled suggests that clupeiform fish are the order of baitfish whale sharks are most likely to feed or attempt to feed on. However, whale sharks are known to feed on other similar planktonic prey items as do these fish species, and it is likely that whale sharks will not feed on baitfish in most circumstances but rather feed alongside baitfish depending on availability of zooplankton and the presence of other marine predators which may chase and herd highly mobile prey into bait balls which make them more accessible for feeding by whale sharks.