The waters around Hawai’i are home to short-finned pilot whales, a species that relies heavily on squid to thrive. A recent study reveals that these dolphins consume millions of squid each year to maintain their deep-diving lifestyle.
Researchers tracked eight individual whales using special tags that recorded their movement, depth, and sounds. They also employed underwater cameras to observe the whales as they hunted. By analyzing drone footage for size estimates, the researchers calculated the energy needed for these whales to swim and dive. This study marks the first time an “energetic budget” has been created for this specific population, highlighting how much energy the whales expend versus what they acquire from their prey. The findings were published in the Journal of Experimental Biology.
William Gough, a postdoctoral researcher at the Hawaiʻi Institute of Marine Biology (HIMB), explains, “Pilot whales are unique among oceanic dolphins because they can dive up to 1,000 meters to hunt for food.” Their deep-diving foraging strategy requires a careful balance of energy consumption and energy intake. Gough emphasizes that this study is just the first step in understanding that balance.
Based on their research, scientists estimated that an adult pilot whale needs between 82 and 202 squid daily to fuel their activities. With around 8,000 pilot whales in Hawai’i, the entire population might consume between 241 to 591 million squid each year.
These whales are genetically distinct from other populations and tend to stay within their pods year-round, hunting deep in the ocean for squid. The researchers shared incredible footage showing these whales navigating dark waters, where the pressure is significantly higher than at the surface. Gough reflected on the privilege of witnessing these elusive creatures in their natural habitat.
Understanding the dietary needs of pilot whales is crucial for their conservation. This knowledge helps monitor changes in the ocean environment that could affect their population. Gough warned that human activities, like shipping noise and climate change, can disrupt their hunting. If the whales expend more energy than they can gain, they risk weakening their health, which can affect their ability to reproduce and recover.
Monitoring the energetic needs of such deep-diving species is increasingly important to ensure their survival. These findings provide essential insights into the lives of short-finned pilot whales and the challenges they face in our changing oceans.
For more on pilot whales and marine life conservation, the Hawaiʻi Institute of Marine Biology offers a wealth of information.
