Echolocation signals of wild harbour porpoises, Phocoena phocoena

  title={Echolocation signals of wild harbour porpoises, Phocoena phocoena},
  author={Anne Villadsgaard and Magnus Wahlberg and Jakob Tougaard},
  journal={Journal of Experimental Biology},
  pages={56 - 64}
SUMMARY Field recordings of harbour porpoises (Phocoena phocoena) were made in the inner Danish waters with a vertical array of three or four hydrophones. The back-calculated source level ranged from 178 to 205 dB re 1μ Pa pp @ 1 m with a mean source level of 191 dB re 1 μPa pp @ 1 m. The maximum source level was more than 30 dB above what has been measured from captive animals, while the spectral and temporal properties were comparable. Calculations based on the sonar equation indicate that… 
Echolocation activity of harbour porpoises (phocoena phocoena) around an offshore gas-production platform-drilling-rig complex.
It is conceivable that by using acoustics alone, a proxy of feeding activity could be surmised by examining the relative incidence of increasing click rates, emitted during range-locking echolocation behaviour, and the associated decreasing interval between clicks, known as “inter-click-intervals (ICI)”.
Swimming patterns of wild harbour porpoises Phocoena phocoena show detection and avoidance of gillnets at very long ranges
The results strongly indicate that porpoises do not usually actively approach gillnets, and the by-catch problem seems, therefore, to be caused by individual animals accidentally being caught.
Sound plays an important role for toothed whales in foraging and communication. However, little is known about acoustic communication in the toothed whale species that only produce narrow band high
Biosonar, dive, and foraging activity of satellite tracked harbor porpoises (Phocoena phocoena)
This study presents bioacoustic recordings in combination with movements and diving behavior of three free-ranging harbor porpoises in Danish waters to show behavioral adaptability necessary for survival in a complex coastal environment and confirm that wildbors use more intense clicks than captive animals.
Echolocation by the harbour porpoise: life in coastal waters
It is argued that such echolocation signals and narrow band auditory filters give the harbor porpoise a selective advantage in a coastal environment.
Harbour porpoise (Phocoena phocoena Linnaeus, 1758) entering the Weser river after decades of absence
It appears unlikely that a single fish species attracts porpoises into the Weser, due to size and life-history considerations of these fish, and due to a strong seasonality of sightings, which indicates a strongSeasonality of harbour porpoise Sightings.
Confirmation of the presence of harbour porpoise (Phocoena phocoena) within the tidal Thames and Thames Estuary
This study documents the presence of harbour porpoise (Phocoena phocoena, Linnaeus 1758) in the tidal Thames from strandings, dedicated surveys and opportunistic sightings. In March 2015, a visual
Diel echolocation activity of harbour porpoises (Phocoena phocoena) around North Sea offshore gas installations
It is concluded that offshore installations may play an important role as nocturnal porpoise-feeding stations in an overfished environment, but that further replicated and controlled studies are required.
Synthetic communication signals influence wild harbour porpoise (Phocoena phocoena) behaviour
We used our novel and programmable Porpoise Alarm (PAL, patd.) to synthesize life-like, electronic harbour porpoise communication signals based on those described for captive animals. In the Little
Characteristics of biosonar signals from the northern bottlenose whale, Hyperoodon ampullatus.
The data show that the northern bottlenose whale emits signals similar to three other species of beaked whale, and these signals are distinct from the three other types of biosonar signals of toothed whales.


Echolocation rates of two harbor porpoises (Phocoena phocoena)
Echolocation rates were affected by feeding, individual difference, and enclosure type such as the net enclosure and the pool, and the porpoise echolocated rates seemed to show acclimation.
Target detection by an echolocating harbor porpoise (Phocoena phocoena).
Together with information on the target strengths of various fishing nets, the results of the present study can be used to predict the distance at which the nets can be detected by harbor porpoises.
Sonar characteristics of the harbour porpoise (Phocoena phocoena): source levels and spectrum
The preliminary data suggest that harbour porpoises search for prey using a narrowbeam, narrowband, high-frequency sonar with a detection range, for single fish of an ingestible size, up to 30 m, and appear to favour foraging close to either the sea surface or the bottom.
Spatial orientation in echolocating harbour porpoises (Phocoena phocoena)
The results suggest that echolocation by odontocetes is used not only for target detection, localisation and classification but also for spatial orientation, with some individual differences between the two animals.
Characteristics of echolocation signals used by a harbour propoise (Phocoena phocoena) in a target detection experiment
The harbour porpoise detected the large sphere at all distances, while the small sphere was detected up to 14 m and the pre-click occurred on average about 270 # sb efore the main click, regardless of target present or not, and was correlated temporally and spectrally to the subsequent main click.
Measurement of echolocation signals of the Atlantic bottlenose dolphin, Tursiops truncatus Montagu, in open waters.
The echlocation signals of two Atlantic bottlenose dolphins, Tursiops truncatus, were measured while the animals were involved in a target‐detection experiment conducted in open waters. The time
Detection distances of bottom-set gillnets by harbour porpoises (Phocoena phocoena) and bottlenose dolphins (Tursiops truncatus).
Transmission beam pattern and echolocation signals of a harbor porpoise (Phocoena phocoena).
The transmission beam pattern of an echolocating harbor porpoise was measured in both the vertical and horizontal planes and the average source level, peak frequency, and bandwidth were 157 dB, 128 kHz, and 16 kHz.
Bycatches of harbour porpoises (Phocoena phocoena, L.) in Danish set-net fisheries
Data on bvcatch of harbour porpoise t Phocoena phocoena L.) in the com m ercial Danish set-net fisheries were sam pled from 5.591km nets in the period 1992 to 1998 using independent observers. A
Biosonar performance of foraging beaked whales (Mesoplodon densirostris)
It is suggested that stable ICIs in the search and approach phases facilitate auditory scene analysis in a complex multi-target environment, and that a concomitant low click rate allows the whales to maintain high sound pressure outputs for prey detection and discrimination with a pneumatically driven, bi-modal sound generator.