Based on extensive data collected through drone video footage, sensors attached to animals, and other methods, scientists have estimated that an adult short-finned pilot whale (Globicephala macrorhynchus) requires between 82 and 202 squid per day (an average of 142 squid), amounting to up to 73,000 individuals per year.

What Are Short-Finned Pilot Whales?

Short-finned pilot whales are large marine mammals belonging to the dolphin family. Members of the genus Globicephala are also known as black dolphins due to their distinctive coloration. In terms of size and behavior, they resemble whales: adults can reach lengths of 3.5 to 6.5 meters and weigh between one and four tons.

These animals prefer warm and tropical ocean waters, though they are sometimes found in more northern regions. Their diet mainly consists of cephalopod mollusks, especially squid, which the whales regularly dive for—sometimes to depths exceeding 1,000 meters. Understanding how much food these marine mammals need, and whether there is enough available in their habitats, is crucial for preserving their populations.

How the Study Was Conducted

Recently, an international team of scientists from the USA, Spain, Australia, and Denmark accurately assessed the daily squid consumption of short-finned pilot whales in Hawaiian waters. The results were published in the Journal of Experimental Biology.

To analyze the animals' behavior and energy expenditure, researchers attached special tags with motion sensors, cameras, and hydrophones to eight pilot whales to record echolocation clicks. Using drone video footage, biologists determined the size of each individual.

Main Findings

Data analysis showed that, on average, each pilot whale makes about 39 deep dives per day. In total, 118 such dives were recorded, reaching depths of up to 864 meters. During these dives, the whales expend about 74 kilojoules of energy per minute, while at the surface, they use just over 44 kilojoules per minute.

Recordings of echolocation clicks revealed that, on average, the animals consume about four squid per dive. Each digested cephalopod provides them with approximately 560 kilojoules of energy.

Daily and Annual Food Requirements

After compiling all the information, scientists calculated the daily diet needed to maintain the whales' energy balance. It turns out that a single adult Globicephala macrorhynchus requires between 82 and 202 squid per day (an average of 142 squid), and up to 73,000 individuals per year.

For the entire population of short-finned pilot whales near Hawaii, estimated at around 8,000 animals, the annual squid consumption amounts to about 416 million individuals, or roughly 88,000 tons of cephalopod mollusks.

Is There Enough Food for the Whales?

Despite these impressive numbers, researchers note that for the squid living in these waters, such consumption is relatively insignificant. Observations show that in Hawaiian waters, pilot whales have access to an abundant and reliable food source, so their future is not considered at risk, biologists conclude.