Strouhal numbers and optimization of swimming by odontocete cetaceans

Strouhal numbers and optimization of swimming by odontocete cetaceans.

Swimming efficiencies of fish and cetaceans have been related to a certain synchrony between stroke cycle frequency, peak-to-peak tail/fluke amplitude and mean swimming speed. These kinematic parameters form a non-dimensional wake parameter, referred to as a Strouhal number, which for the range between 0.20 and 0.40 has been associated with enhanced swimming efficiency for fish and cetaceans. Y...

Comparative kinematics and hydrodynamics of odontocete cetaceans: morphological and ecological correlates with swimming performance.

Propulsive morphology and swimming performance were compared for the odontocete cetaceans Delphinapterus leucas, Orcinus orca, Pseudorca crassidens and Tursiops truncatus. Morphological differences were apparent among the whales. The general body contour and low-aspect-ratio caudal flukes of D. leucas indicated that this species was a low-performance swimmer compared with the other species. Pro...

A comparison of encephalization between odontocete cetaceans and anthropoid primates.

There have been very few studies of brain size and encephalization in cetaceans and essentially none that have made direct quantitative comparisons of cetaceans and another mammalian group using large normative samples. In the present study two different measures of encephalization were calculated and used to rank and compare 21 odontocete species and 60 anthropoid primate species. Comparisons ...

Hearing and Auditory Evoked Potential Methods Applied to Odontocete Cetaceans

Auditory evoked potential (AEP) procedures have been increasingly used to measure hearing processes in aquatic mammals. They have been demonstrated to be useful in measuring the audiograms of stranded animals like infant sperm whales (Physeter macrocephalus) and Risso’s dolphins (Grampus griseus). Modulation rate transfer functions (MRTF) demonstrating appropriate stimulus presentation rates ar...

The Metabolic Cost of Sound Production in Odontocete Cetaceans