Wilderness Wednesdays are back! If you’ve never heard of them, now is your chance to learn some incredible facts about some of the wildlife we have here on the BC coast. This week we’re featuring the Harbour Seal.
Often confused for their much larger relative, the Sea Lion, Harbour Seals differ in a few distinct ways. One dead giveaway is that Sea Lions have visible external earflaps; whereas Harbour Seals are considered “earless seals.” In addition to their larger stature, Sea Lions also have longer flippers allowing them to support themselves and walk on land. However, Harbour Seals look more than a bit like perogies flopping on shore due to their inability to rotate their rear flippers forward.
The Harbour Seals’ apparent struggle on land is offset by their strengths in the water. Using very oily “tears” to protect their large eyes, these guys can see well in deep, dark waters. How deep? Harbour Seals have a dive reflex that allows them to dive to over 300 m, holding their breath for as long as 25 minutes! This reflex automatically forces the seal to hold its breath when submerged, reducing its heartbeat by 10% and therefore slowing blood circulation (except to the vital organs – the heart and brain). Failing their ability to see that far down, the seals can extend their long “feeling” whiskers forward to inspect foreign objects and surfaces; an ability that comes in handy often while locating prey such as rockfishes, greenlings, smelt, perch, herring and flatfishes. If sight and feeling aren’t cutting it at these depths, their ability to hear 14 times better under water (160 kHz) than on land (12 kHz) certainly might. This incredible sense of hearing has led many scientists to believe that Harbour Seals have the ability to echolocate. Blind Harbour Seals have been known to not only survive, but actually thrive in the wild using these other sensory advantages.
If all of these abilities are not enough to convince you that Harbour Seals are one incredible mammal, consider this: Harbour Seals have an automatic shutoff mechanism in the nervous system that prevents breathing at inappropriate times. This allows them to sleep underwater for short periods of time, and to surface subconsciously to breathe!
Pretty impressive, right?! For more on these impressive animals check out the Vancouver Aquarium’s website at: http://www.vanaqua.org/learn/aquafacts/otters-and-pinnipeds/harbour-seals. But if you are looking for a more personal experience with the Harbour Seals, we recommend a trip with Spirit of the West!