Across their range, humpback whales feed in locations with varying degrees of direct and indirect human presence and disturbance. The goals of our research proposal are to (1) use novel tag technology and visualization tools to measure, visualize, and quantify the foraging behavior of humpback whales across a range of ecological systems and prey types; (2) determine the types and amount of human activity across ecological systems (e.g. fishing, shipping) that may affect humpbacks in these regions, and (3) synthesize tag-derived data and human activity data together to document the types and magnitudes of risk that humpback whales face throughout their foraging areas in a geospatial framework. This synthesis will directly inform measures to identify and mitigate significant risks of negative interactions between humpback whales and human activities.
Humpback whales are unique among the baleen whales in their maneuverability and group foraging behaviors. For the past 10 years we have been studying the underwater feeding strategies that these whales use and how they change as a result of different prey and environmental conditions. Through the combination of multi-sensor suction cup tags and the newly developed visualization software, we can now understand how these ocean giants behave in a number of different conditions and determine how they respond to changes in their prey. We now have a growing literature on the kinematics of humpback whale feeding and the myriad approaches that these whales utilize to maximize their foraging efficiency and support their enormous energetic demands. Furthermore, we find significant individual variability in feeding behavior and population-level consistency in the lateralization of these behaviors, which is also found in other animal populations with complex ecologies, including primates.
Along with multi-sensor recording tags, we have been working with the National Geographic Remote Imaging department to deploy CritterCams on humpback whales. These video-recording tags allow us to corroborate tag sensor data and visualize the underwater behavior of humpback whales in unprecedented ways. These tags have allowed us to determine new feeding behaviors and how whales respond to changes in their prey. For example, we have determined that bottom feeding in humpback whales may be a cooperative strategy involving more than one whale, similar to bubble-net feeding. We have also found that whales generally do not disturb the substrate when bottom feeding but rather target dense mats of fish that are found schooling just above the substrate.