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.

Upside-down swimming behaviour of free-ranging narwhals.

Background: Free-ranging narwhals (Monodon monoceros) were instrumented in Admiralty Inlet, Canada with both satellite tags to study migration and stock separation and short-term, high-resolution digital archival tags to explore diving and feeding behaviour. Three narwhals were equipped with an underwater camera pod (Crittercam), another individual was equipped with a digital archival tag (DTAG), and a fifth with both units during August 2003 and 2004.

Results: Crittercam footage indicated that of the combined 286 minutes of recordings, 12% of the time was spent along the bottom.

Preliminary evidence for signature vocalizations among free-ranging narwhals (Monodon monoceros).

Animal signature vocalizations that are distinctive at the individual or group level can facilitate recognition between conspecifics and re-establish contact with an animal that has become separated from its associates. In this study, the vocal behavior of two free-ranging adult male narwhals (Monodon monoceros) in Admiralty Inlet, Baffin Island was recorded using digital archival tags. These recording instruments were deployed when the animals were caught and held onshore to attach satellite tags, a protocol that separated them from their groups.

Call usage learning in gray seals (Halichoerus grypus).

Call usage learning can be demonstrated on 4 different levels: signaling on command, signaling and refraining from signaling on command, responding to a trained stimulus with a signal from a specific signal class, and responding to the playback of any untrained stimulus with one from the same signal class. Two young gray seals (Halichoerus grypus) were trained successfully to demonstrate the first 2 levels. They also learned to respond to 9 moan stimuli and 9 growl stimuli with vocalizations of the same class (Level 3).

A gray seal's (Halichoerus grypus) responses to experimenter-given pointing and directional cues.

A gray seal (Halichoerus grypus) was trained to touch a target on its left or right by responding to pointing signals. The authors then tested whether the seal would be able to generalize spontaneously to altered signals. It responded correctly to center pointing and head turning, center upper body turning, and off-center pointing but not to head turning and eye movements alone.