麻豆淫院

Currents can affect marine animals' locomotion, energy expenditure and ability to navigate; the force of currents may cause them to drift off-course of their intended trajectory.

A study July 17 in PLOS Biology by Richard Michael Gunner at the Max-Planck-Institut f眉r Verhaltensbiologie, Germany, suggests that Magellanic penguins can sense current drift and maximize navigation efficiency by alternating between traveling in a direct route in calm conditions and swimming with the flow of strong currents allowing them to conserve energy while navigating toward their colony.

Magellanic penguins travel long distances without visual landmarks to forage and return to their colonies to feed their chicks. However, penguins' ability to adapt their routes to current drift without visual cues over long distances is poorly understood.

To investigate penguins' ability to orient toward their colony and whether they can sense current drifts, researchers fitted 27 adult penguins at the San Lorenzo Magellanic penguin colony, Peninsula Vald茅s, Argentina, with GPS and IMU loggers, and recorded one foraging trip made by each penguin before recapturing to remove the devices. The researchers analyzed a suite of movement parameters, including dive profiles, compass headings, speeds and durations, to model the penguins' navigation under different current conditions.

The researchers found that penguins alternate between traveling in a direct route and swimming with the flow of the current to maximize navigation efficiency. In calm currents, penguins maintained precise line-of-sight routes to their colony. In stronger currents, they swam with the direction of the current flow, increasing travel distance, but allowing them to conserve energy, suggesting that penguins are aware of current drift relative to their out-of-sight destination.

These findings require further study, as the sample was limited to a single trip made by 27 penguins. Future research may attempt to replicate the results in other penguin populations and other marine animal species, and to explain the exact mechanism by which penguins sense and adapt to varying ocean currents.

According to the authors, "Our results indicate that penguins notice discrepancies between their intended path and actual displacement over ground, then adjust accordingly. While penguins still aim broadly toward the colony under strong currents, they exhibit a more dispersed heading distribution, potentially reflecting repeated or fine-scale corrections to compensate for the drift. Such behavior is consistent with effective navigation even when out of sight of land. This central finding is a valuable contribution to our understanding of navigation ability in marine animals."

The authors add, "Magellanic penguins finding their way back to their nests from the open ocean subtly adjust their headings to exploit tidal currents, following paths that reduce energy costs while maintaining remarkable accuracy. Rather than swimming directly home, they drift laterally with the tides, balancing travel efficiency with opportunistic foraging along the way."