Bottlenose dolphins often listen for their next meal.
While they eat many different fish species, among the favorites in Sarasota Bay are soniferous or noise-making fish, which include pigfish and toadfish.
That’s right, dolphins, which are famous for their sonar, use passive listening to help when hunting prey.
Building on ground-breaking work by the late Dr. Nélio Barros, and Dr. Damon Gannon, our foraging ecology research indicates that while soniferous fish make up only 6% of the fish species in Sarasota Bay, these species make up 52% of the dolphins’ diet.
And dolphins are selective feeders, not opportunistic predators.
That means that relatively less abundant species like pig fish and toad fish tend to be selected over the more abundant mullet.
Further, the energy content of prey species varies seasonally, which may cause dolphins to vary their diet at different times of the year.
Some important dolphin prey species, such as pinfish have shown a decline in average body size since our research began in 2004.
Thus, less available energy is obtainable from each prey capture event. This might have negative implications for the growth of weaning dolphin calves, which are often observed to feed on pin fish.
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