Reports of cooperative human-dolphin fishing date

Dolphin copulation happens belly to belly; though many species engage in lengthy foreplay, the actual act is usually brief, but may be repeated several times within a short timespan. The gestation period varies with species; for the small Tucuxi dolphin, this period is around 11 to 12 months, while for the orca, the gestation period is around 17 months. Typically dolphins give birth to a single calf, which is, unlike most other mammals, born tail first in most cases.[45] They usually become sexually active at a young age, even before reaching sexual maturity. The age of sexual maturity varies by species and gender.
Dolphins are known to display non-reproductive sexual behavior, engaging in masturbation, stimulation of the genital area of other individuals using the rostrum or flippers and homosexual contact.[46][47] Various species of dolphin have been known to engage in sexual behavior up to and including copulation with dolphins of other species. Sexual encounters may be violent, with male dolphins sometimes showing aggressive behavior towards both females and other males.[48] Occasionally, dolphins behave sexually towards other animals, including humans.[49]
Feeding
Various methods of feeding exist among and within species, some apparently exclusive to a single population. Fish and squid are the main food, but the false killer whale and the orca also feed on other marine mammals. Orcas on occasion also hunt whale species larger than themselves.[50]
One common feeding method is herding, where a pod squeezes a school of fish into a small volume, known as a bait ball. Individual members then take turns plowing through the ball, feeding on the stunned fish.[50] Coralling is a method where dolphins chase fish into shallow water to catch them more easily.[50] Orcas and bottlenose dolphins have also been known to drive their prey onto a beach to feed on it, a behaviour known as beach or strand feeding.[51][52] Some species also whack fish with their flukes, stunning them and sometimes knocking them out of the water.[50]
Reports of cooperative human-dolphin fishing date back to the ancient Roman author and natural philosopher Pliny the Elder.[53] A modern human-dolphin partnership currently operates in Laguna, Santa Catarina, Brazil. Here, dolphins drive fish towards fishermen waiting along the shore and signal the men to cast their nets. The dolphins’ reward is the fish that escape the nets