Hydrodynamic handicaps and organizational complexity in the foraging behavior of two free-ranging penguin species
Résumé
Background: Animal movement exhibits self-similarity across a range of both spatial and temporal scales reminiscent
of statistical fractals. Stressors are known to induce changes in these statistical patterns of behavior, although the
direction and interpretation of such changes are not always clear. We examined whether the imposition of known
hydrodynamic disruptors, bio-logging devices and flipper bands, induces changes in the temporal organization
(complexity) of foraging sequences in two penguin species, little penguins (Eudyptula minor) and Adélie penguins
(Pygoscelis adeliae).
Results: Detrended fluctuation analysis showed that foraging sequences produced by little penguins carrying larger
loggers were more complex, i.e., were more erratic tending toward greater stochasticity, than those carrying smaller
loggers. However, logger size did not affect complexity in foraging sequences of Adélie penguins. Logger position
was associated only weakly with altered complexity in little penguins, with individuals carrying loggers in the middle
of their backs displaying slightly more complex dive sequences than those carrying loggers lower on their backs.
Finally, despite their known negative effects on penguin fitness, flipper bands were not associated with dive sequence
complexity in little penguins.
Conclusions: Despite that externally attached devices can disrupt certain behavioral parameters in diving seabirds,
we found mixed evidence in support of the hypothesis that such devices significantly disrupt the time-structured
organizational properties of foraging sequences in the two penguin species investigated. However, smaller species
carrying larger loggers, and perhaps those positioned higher on their backs, may experience an added element of
noise in their behavioral sequences that may indicate a departure from foraging behavior observed under normal,
unburdened conditions.
Origine | Publication financée par une institution |
---|
Loading...