Lip-reading in remote subjects: an attempt to quantify and separate ingestion, breathing and vocalisation in free-living animals using penguins as a model

摘要: A new mandibular sensor is presented here based on the use of a Hall sensor, attached to one mandible, opposite magnet, other mandible. Changes in voltage, proportional magnetic field strength, and thus inter-mandibular angle, are recorded logger. This system was tested seven captive Adelie penguins (Pygoscelis adeliae) three gentoo papua) during: (1) feeding trials land, where birds were given known quantities types food; (2) water allowed swim dive freely. In addition, six free-living Magellanic (Spheniscus magellanicus) equipped with for single foraging trips. Angular signatures looked instances when both might open their beaks, it discovered that five major behaviours could be identified: ingestion, breathing, calling, head shaking preening. Captive showed prey mass determined reasonable accuracy (r 2=0.92), there some indication type resolved if recording frequency high enough. Vocalisations (arc calls) took <0.7 s mean maximum beak angles 4.2° (SD 1.3), distinguished by relatively gradual change angle degree symmetry. Beak shakings distinguishable short duration (multiple peaks <0.5 s) minimal (<0.5°). Preening behaviour apparent due multiple decreasing (angles <8°). Breathing subdivided into during porpoising, characteristic double peak recorded, normal surface rests between dives. During only primary (mean 25.1°, SD 4.7) occurred bird out second 5.9°, 4.1). birds, breaths as series openings closures, showing variation amplitude according an recovery from previous preparation subsequent come. The measuring shows considerable promise elucidating many hitherto intractable aspects animals.