Effects of Clock-Shifting Wild Seabirds

By Fatin Chowdhury ‘19

seabird.jpg

Figure 1. The albatross, a pelagic seabird.

Humans have been curious about animal navigation for millennia, but the strategies and adaptations used by non-human organisms to travel are still unknown. Oliver Padget, a doctoral student at Oxford University in England, recently published findings that examined the impact of solar orientation on pelagic seabird navigation patterns. The study suggested that by using the sun as a compass, animals can find food sources, embark on seasonal migration, and explore previously unencountered locations.

Due to the lack of knowledge specifically relevant to pelagic seabirds, the experimenters altered the endogenous, light-oriented internal clocks of Manx shearwater birds (Puffinus puffinus). 61 Manx shearwater birds were subject to clock shifting for five to seven days, and then were released at sea, 20 to 48 kilometers away from their colonies, for five days. The researchers used technologies such as linear mixed models and likelihood ratios to examine data; GPS telemetry was also used to track the locations of selected specimens.

The researchers found a statistically significant consequence of clock shift with the navigation back to the colony. The experiment resulted in “phase shifting” of the experimental group’s natural, sun based internal clocks. The birds incorrectly interpreted the location of the sun while returning to their colonies. As the birds oriented themselves in flight according to induced clock shifts, the researchers concluded that the birds used a sun compass that adjusted over the hours of the day. It was concluded that variations in instantaneous flight towards the colony were explained by differing release dates, with impacting factors such as environmental conditions being proposed.

While the clock shift was important in affecting homing behaviors, the recognition of environmental landmarks also influenced the birds. The novel use of clock-shifting manipulation on wild animals may have further applications and help scientists understand the navigational tendencies of terrestrial species. In future experiments, the distance from the release site to the colony may be increased to see if similar orientation adjustment responses are observed.

References

  1. O. Padget, et al., In situ clock shift reveals that the sun compass contributes to orientation in a pelagic seabird. Current Biology 28, 275-279 (2018). doi: 10.1016/j.cub.2017.11.062.
  2. Image retrieved from: https://unsplash.com/photos/jfNbjjj5FEY
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