Adaptive Value

Electroreception allows platypuses to forage for food at the darkest of times.

Platypuses are largely nocturnal and are capable of hunting up to half its body mass in prey underwater (Manager & Pettigrew 1995). A control study has shown that platypus feeding behavior is dependent on electroreception because all other sensory stimuli, such as sight and sound, are inhibited while submerged.

Platypuses spend on average 41% of the time in an overnight study patrolling for food, defined by a repetitive left-right swinging of the bill. When electrical stimulus is present, the platypus has been observed to swing its head toward the source although the threshold response varies depending on the orientation of the source to the bill. If the platypus swims over an electric stimulus, it almost immediately returns to the vicinity and investigates the area (Manger and Pettigrew 1995). Therefore, this sophisticated detection system allows the platypus to find and eat food in deep sea environments lacking any other sensory stimulus.

It is yet unknown how platypuses are able to differentiate between other platypuses and prey. It is possible that they rely heavily on mechanical sensing of fellow platypuses to determine if what they are chasing is a friend or foe.