THE TRACKS OF FORAGING PENGUINS AND A REMOTE-CONTROLLED ROBOT ASSESSING
THE AMOUNT AND DISTRIBUTION OF THEIR PREY, Nov-Jan 2012-13.
During the 2012-13 austral summer season, beginning in mid-November, we deployed a self-propelled torpedo-like vehicle from Cape Crozier to determine the prey resources available to the penguins in that colony, at the same time as we put satellite tags of penguins to track their foraginng. This robot, called an iRobot (http://www.irobot.com/en/us/robots/Maritime/Seaglider/Details.aspx), had an acoustic sensor --- a fish finder --- that showed where and how large are the schools of fish and krill offshore from the colony. The glider is propelled by its buoyancy, which it regulates by using water pumps. With more buoyancy it wants to go up, but with less it wants to go down. Its wings direct this movement to go sideways, i.e. horizontal.
|The robot, which is yellow, weighs 52kg (110 lbs), is about 2m (6 ft) long, with wings spanning 1m (3 ft), was steered by persons from the University of Southern Mississippi, from Mississippi. The robot followed an undulating course (up and down, depending on buoyancy), going back and forth across the area where we know the Crozier penguins have foraged in the past (see map below). Each time it surfaced, it pointed downward to project its antenna toward the sky (see photo to left). Then it transmited the data recently collected and received commands if its course needed to be changed. The glider reported its position to its operators.|
|These maps showed where Crozier penguins foraged in the early, middle and late season, compared to glider tracks.
While the robot surveyed the area, we deployed electronic instruments, taped to the back of penguins, to determine where they actually were foraging and what their diving behavior was like. These instruments were also talking to satellites, which relayed the diving information to us. Here is a picture showing one of these tags taped to the back of a penguin: