Yes, I am a total fail on keeping up with my blogging, and I don’t expect that to change anytime soon. BUT I am presenting a paper called Harbour Seals (Phoca vitulina) Can Steer by the Stars (Mauck et al. 2008) on Friday, so I thought I’d write a blog to share the science and also to help me prepare for my presentation. The internet link is here:
However, you should also be able to find the whole research article by using google scholar if you want.
The article is really neat because the researchers built a custom made swimming planetarium for the seals to interact in! The goal of the study was to determine if seals are capable of using the stars for navigation, a skill that would be essential for animals that must hunt in the dark many miles from visible land/landmarks. The researchers slowly trained the seals to understand the purpose of the experiment by using a laser pointer to tell the seals which star was the “lodestar” – a star used for celestial navigation – and that their goal was to orient to it. The experiment was conducted with two male harbor seals. After training, one seal immediately identified the correct star direction over 80% of the time. The other seal took a few more sessions, but ultimately both seals were able to perform at 100%. (For a trial to be considered a success, the seals had to be within 30 degrees of the precise direction.)
Since the seals could orient effectively towards the specific lodestar, the next issue will be determining whether their navigation is by a time-independent star compass (animals recognize constellations and follow that trajectory regardless of time elapsed) or a time-compensated star compass (animals follow a star, but adjust their headings depending on time of day). The latter is deemed “true navigation,” a rare skill among animals.
Although this research only used two harbor seals under non-natural conditions, it was a great step towards understanding seal navigation behavior when far from shore. Most importantly though, this was the first documentation of celestial navigation among marine mammals.