For the past several months we’ve been studying behavioral responses of pilot whales to the sounds of predators off of Hatteras, NC. The objective of this project is to understand how pilot whales respond to the sounds of potential predators (e.g. killer whales), which share some characteristics with the sounds of some military mid-frequency active sonars. We use DTags to examine the responses of pilot whales to determine whether social structure influences the response to acoustic stimuli. The stimuli are played to the tagged pilot whale and its associated group in a randomly selected series of playbacks: two control sounds consisting of humpback whale calls and pilot whale calls, and one potential predatory killer whale call. We use these behavioral and acoustic observations to create a conceptual model of the anti-predator behavior of pilot whales to improve our understanding of their response to certain anthropogenic sounds. This project is funded by the Strategic Environmental Research and Development Program.
Thanks to decent weather offshore of Hatteras last weekend, we were able to conduct a full series of acoustic playbacks on a small group of pilot whales. We’ve conducted eight playbacks so far this year and would like to complete a few more before the end of the year.
We also collected skin samples from three of the 16 animals in the tagged whale’s social group and took over 500 photo-identification images (photographs of unique dorsal fins from different animals). Genetic analyses of the samples along with the photo-identification images will address questions of social structure and residency patterns of pilot whales off our coast.
Other animals observed: offshore bottlenose dolphins, Risso’s dolphins, manta ray, ocean sunfish and a hammerhead shark.
There always seems to be a note about weather conditions when writing about field work so here is our bit on why good offshore forecasts are never a guarantee. Friday, Saturday and Sunday forecasts were supposed to be beautiful but Friday turned for the worst after lunch time and made for an adventurous boat ride back to the dock. Sunday, however, was one of those beautiful days that make every rough day on the water worth it.
Thanks to Captain Huck of the F/V Samanna and Captain Jim of the F/V Hog Wild for putting us on pilot whales each day and for getting our crew 40 miles offshore and back safely!
