Experts theorize this is a revenge behavior resulting from one of the orcas encountering traumatic event with a boat. The problem is, other orcas are emulating it.
> Experts theorize this is a revenge behavior resulting from one of the orcas encountering traumatic event with a boat. The problem is, other orcas are emulating it.
Crows, IIRC, communicate the identity of other individuals who are witnessed to injure crows to other crows; orcas communicating similarly but generalizing to a class of offenders seems not too surprising.
There are a lot of homebrew ones out there using stuff like windshield wiper motors hooked to off the shelf control circuitry [1]. It "functions" but has anyone looked into the effects? Doesn't hurt to see if there is a correlation.
The video below is an example. It also has rudder feedback...so that very easily could cause an oscillating signal. Which would also vary in pitch as the rudder was hit by the Orca.
I know I can hear PWM'ed stepper motors...and many younger people complain about them. I wonder what that sounds like to an animal which uses sonar and can hear different ranges.
can try,
basically a motor-sensor loop can "hold position" by noticing when it has gone past some threshold then corrects in the opposite direction ... rinse and repeat.
Some systems may have thresholds that cause the rudder to "quiver" while staying on course, To an intelligent creature exquisitely sensitive to things quivering in the water this could be a major annoyance.
the main types of motors likely used in this application are Servos and Steppers
Maybe the autorudder is the issue. PWM noise. In the previous article there was mention that the boats had autorudders on them.
Perhaps this is happening more because more people are using invasive noise producing equipment.
Of course...I am not an Orca researcher, nor am I in Spain. I wonder if it should be mentioned to someone official?