SnotBot Alaska Expedition, Dispatch #5 – SnotBot has a brother
This is the fifth in a series of dispatches sent from the field during the recent SnotBot Alaska expedition. The first dispatch can be found here.
The weather took a turn for the worse today with wind and rain – but we had a master plan – we tested for the first time (with whales) our new research drone EarBot.
What is EarBot? you ask – As I am sure that you know whales live in a world of sound. Communication, feeding, predator detection, reproduction: all of the most important aspects of their lives rely on acoustics. Acoustics are a gateway into the world of whales. EarBot is an initiative to study whales acoustically using drones – with the same philosophy as SnotBot, getting research tools close to the animals (while keeping researchers away) and collecting high quality data without the whale even knowing. Now, we have an opportunity to link our president and founder’s (Dr. Roger Payne) expertise in bioacoustics to our present expertise in robotics by attaching hydrophones to a waterproof drone that can land in the water near a whale & transmit back to researchers both the sounds that the animals are making and the sounds that they are hearing and video; creating a mobile, flexible and practical platform for studying whales acoustically: EarBot.
Existing methods of acoustic data collection broadly fall under two categories: fixed and vessel based hydrophones. Both undoubtedly have valuable applications, but are limited by the flexibility they can provide. Fixed hydrophones are taken out to sea and moored in place, either on the seafloor, in the water column or at the surface. They can be left at sea for months at a time and are excellent for collecting large, long-term data sets. They are however complex and expensive tools which require significant resources to deploy, maintain and recover; and are highly inflexible. For times when more flexibility is required, scientists use hydrophones deployed from boats. This automatically introduces a problem. The very presence of a boat (particularly if the engine is on) is what scientists call a confounding variable that could change the behaviour of the whale & diminish the quality of the acoustic data collected.
To avoid disturbing the whale, the engine can be cut. This, in turn, reduces the flexibility of the data collection. If the whales move off to another location, the scientists have a choice to make between getting closer to the whales but in the process potentially disturbing them, or leaving them undisturbed but being too far away to gather good data. This is a decision they must face: whales are dynamic animals, often moving through their environment at speed in unpredictable ways. It is perfectly logical to have an equally dynamic and flexible way of studying them, yet until now this has been somewhat of a fantasy. Enter EarBot. EarBot will allow us to follow a group of whales as they navigate through their environment, collecting acoustic data from undisturbed whales behaving in a far more natural manner. Current drones have a range of over 3 miles, so the researcher (and consequently their research vessel/platform) could be an enormous distance away as you collect data.
Moreover, EarBot could get much closer to the whales than the traditional methods of acoustic data collection. The closer your hydrophone to the whale, the more acoustic information you receive. This is something we can easily associate with: the closer you are to a sound, the better you can hear it. As scientists we are focused on applying this technology to our own specific research goals/interests. Of course, as with SnotBot, the more we consider this tool, the more potential applications become apparent. Indeed, much of the value of the EarBot program could come from developing it as a tool for other researchers/interested parties.
As with SnotBot we hand launch the EarBot but that is where the similarities end, we fly EarBot to a location land in the water and turn the engines off. A separate battery runs the hydrophone and the FM transmitter sending the signal back to the boat, we record sounds on EarBot and on a recorder on the boat. As a control we have the same calibrated hydrophone on the boat recording all that we hear. As if this was not enough, EarBot has a camera on a stabilized waterproof gyro that allows us to send back live images form either above the water when flying or below the water when concurrently recording undersea sounds. We can even pan and tilt this camera.
Today we conducted 7 EarBot flights, on 3 occasions we took off from the water and flew EarBot to another location closer to the whales and landed back in the water and turned the engines off. We were getting some electronic interference so we will not be winning a Grammy for the recordings but we are over the moon with these first tests and results – huge thanks go to the Big G Foundation who supported the development of the first EarBot prototype and to Parley who are supporting this expedition.
Best Fishes from Alaska.