... tested which mechanism is used to escape from acoustic allometry by probing vocal tract allometry in a proven mammalian vocal learner, the harbour seal ( Phoca vitulina ). We tested whether vocal tract structures and body size scale allometrically in 68 young individuals. We found that both body length...

...-power accelerometers mounted on the head. To test this notion, a harbour seal ( Phoca vitulina ) was trained to wear an OpenTag (sampling at 200 or 333 Hz with ±2 or ±16 g clipping) on its head while catching fish prey in front of four underwater digital high-speed video cameras. We show that both...

...Sven Wieskotten; Björn Mauck; Lars Miersch; Guido Dehnhardt; Wolf Hanke SUMMARY Harbour seals can use their mystacial vibrissae to detect and track hydrodynamic wakes. We investigated the ability of a harbour seal to discriminate objects of different size or shape by their hydrodynamic signature...

...S. Wieskotten; G. Dehnhardt; B. Mauck; L. Miersch; W. Hanke SUMMARY The mystacial vibrissae of harbour seals ( Phoca vitulina ) constitute a highly sensitive hydrodynamic receptor system enabling the seals to detect and follow hydrodynamic trails. In the wild, hydrodynamic trails, as generated...

...S. Wieskotten; G. Dehnhardt; B. Mauck; L. Miersch; W. Hanke SUMMARY Harbour seals can use their vibrissal system to detect and follow hydrodynamic trails left by moving objects. In this study we determined the maximum time after which a harbour seal could indicate the moving direction...

...Frederike D. Hanke; Ronald H. H. Kröger; Ursula Siebert; Guido Dehnhardt SUMMARY Previous photorefractive results from harbour seals indicated the presence of a multifocal lens. This was surprising because the evolution of multifocal lenses has served to compensate for chromatic aberration...

... a harbour seal to swim predefined courses, thus generating biogenic hydrodynamic trails. The structure of these trails was measured using Particle Image Velocimetry. A second seal was trained to search for and track the trail after the trail-generating seal had left the water. Our trail-following seal...

.... This study focused on the ontogenetic changes in cardiac responses to respiration in quietly resting, pre-weaned harbour seal pups ( Phoca vitulina ). During periods of quiet rest, breathing became episodic,eupnoea interspersed with periods of apnoea. Little change was observed in respiration (∼35 breaths...

...Nicole M. Elliott; Russel D. Andrews; David R. Jones SUMMARY While diving, harbour seals ( Phoca vitulina ) manage their oxygen stores through cardiovascular adjustments, including bradycardia, a concurrent reduction in cardiac output, and peripheral vasoconstriction. At the surface,post-dive...

...Christian Jørgensen; Christian Lydersen; Ole Brix; Kit M. Kovacs SUMMARY This study investigated physiological and behavioural aspects of diving development in pups of the harbour seal Phoca vitulina . Behavioural data (4280 h, 6027 dives) from time/depth recorders ( N =13) deployed on pups aged 0...

... of the blood O 2 store and the duration of aerobic metabolism ( Davis and Kanatous, 1999 ). dive response heart rate laser-Doppler muscle blood flow myoglobin near-infrared spectroscopy oxygen store harbour seal Phoca vitulina. © The Company of Biologists Limited 2001 2001 16 8...

... revealed that cooling below normal skin temperature impairs sensitivity, the present study investigates the tactile sensitivity of the vibrissal system of harbour seals at varying ambient temperatures. Using plates bearing gratings of alternating grooves and ridges, the texture difference thresholds of two...