Fine-scale foraging movements by fish-eating killer whales () relate to the vertical distributions and escape responses of salmonid prey ( spp.).

Background: We sought to quantitatively describe the fine-scale foraging behavior of northern resident killer whales (), a population of fish-eating killer whales that feeds almost exclusively on Pacific salmon ( spp.). To reconstruct the underwater movements of these specialist predators, we deployed 34 biologging Dtags on 32 individuals and collected high-resolution, three-dimensional accelerometry and acoustic data.

A versatile pitch tracking algorithm: from human speech to killer whale vocalizations.

In this article, a pitch tracking algorithm [named discrete logarithmic Fourier transformation-pitch detection algorithm (DLFT-PDA)], originally designed for human telephone speech, was modified for killer whale vocalizations. The multiple frequency components of some of these vocalizations demand a spectral (rather than temporal) approach to pitch tracking. The DLFT-PDA algorithm derives reliable estimations of pitch and the temporal change of pitch from the harmonic structure of the vocal signal.