Sperm whales in the Gulf of California prey heavily upon jumbo squid, which has been verified through stomach content analysis and stable isotope analysis, although sperm whale hunting behavior has remained understudied. Davis and colleagues attached satellite dive recorders to 5 sperm whales and 3 jumbo squid to investigate the diving behavior of these two mesopelagic predators. This study found that sperm whales dive and hunt within the same depth ranges that jumbo squid persist, around 100 to 500 meters deep. Results also indicate that squid may be more susceptible to predation following surfacing events in which they feed, and at depths of greater than 250 meters where oxygen content of the water is decreased.
This study showed the use of geographic data to analyze the predator-prey interactions in a marine environment. Maps within the paper, which show bathymetry layered beneath whale tracks, exemplify the use of GIS software ArcView to show the spatial content of both species within the study region of the Guaymas Basin of Baja California. Annotated maps implemented both spatial and temporal data to show the tracks of the 5 sperm whales over the duration of the study. Although this study did not make use geographic information science, the use of maps and visual context is vital to investigating species behavior and movement trends. Tracks such as these are directly applicable to data I am working with, but at a shorter temporal scale.
Davis, R., Jaquet, N., Gendron, D., Markaida, U., Bazzino, G. & Gilly, W. (2007) Diving behavior of sperm whales in relation to behavior of a major prey species, the jumbo squid, in the Gulf of California, Mexico. Marine Ecology Progress Series, 333, 291–302.
