Investigators: Dr. Leigh G. Torres
Much of how whales and dolphins find food remains a mystery to scientists. These animals are equipped with multiple sensory systems that are well-developed for use in the marine environment – sight, sound, touch, smell, and biomagnetism - but each sense’s ability to increase feeding opportunities depends on the distance to the target, called ‘the scale’. Vision works best at small scales (<20 m), while listening is more helpful when farther away from prey (1 km). Through “scale-of-senses” schematics, I illustrate how whales and dolphins interchange their different senses to find food as a function of distance to prey.
These schematics illustrate the hypothetical interchange of six sensory modalities (vision, acoustics, olfaction, tactile: prey-derived, tactile: oceanographic, biomagnetism) by dolphins and baleen whales to locate prey at spatial scales ranging from 0 m to 1000 km. The schematics illustrate how a cetacean integrates sensory modalities to form an adaptive foraging landscape as a function of distance to prey.
The scale of senses schematics are not absolute, but rather are highly flexible, allowing for case-specific application and enhancement with improved understanding of cetacean sensory capability. The presented framework serves to improve our understanding of functional cetacean foraging ecology, and develop new hypotheses, methods and results regarding how cetaceans forage at multiple scales.
I am continuing this line of research by investigating the acoustic and visual signals that baleen whales may use at multiple spatial scales to locate prey.
L. G. Torres, “A sense of scale: Foraging cetaceans' use of scale-dependent multimodal sensory systems”, Marine Mammal Science, vol. 33, no. 3, 2017.
Figure 2. Scale-of-senses schematic of the hypothetical interchange of sensory modalities used by baleen whales to locate prey at variable scales. The line for audition of signals from prey is faded to denote a lack of evidence for this sensory system in baleen whales. X-axis on log scale, with equivalent metric distance given in gray type, and associated scale below. Y-axis ranks the relative use of each sensory modality between 0 (no contribution) and 10 (highest contribution) relative to its own information capacity, not relative to other senses.