What is a sound footprint? Working with whales is always a fascinating insight into their intelligence and how they use what is in their environment to their advantage. One of the ways we see just how clever our whales can be is through the use of a sound footprint. A marine environment is all about sound and if you cannot be easily heard then you are less likely to be easily found. Ships anchor just off the Fremantle coastline as they wait to pickup or drop-off cargo and during this time they will still have generators working for power onboard. The steady and consistent sound of these motors echoes out into the surrounding environment and for our whales instead of avoiding the area they do the complete opposite. Mother whales and their newborn calves are vulnerable to being found by a Humpback Whales top predator, the Orca.
The mother whales will use everything they can to ensure their little ones safety and survival. Resting closely to the ships the mother whales will hide in the sound footprint created by the vessels which means that any other whales or Orca in the area will not hear the whispered communications between mother and calf, but instead the noise of the ships. It works very well for the visiting whales and today we observed a mother whale and her calf resting in the sound footprint of the ships. She also had a male escort travelling with her which adds a second layer of protection for her calf. Interestingly it is not just ships at anchor whales will use as on many occasions we will have all age groups of Humpback Whales hiding in our sound footprint as well. It can be to hide from other whales or disguise themselves when approaching another pod of whales. Each time we observe this behaviour we learn more about the wonderful intelligence of the Humpback Whales we enjoy spending time with each day.