This journal is brought to you by:
- Mrs. Gillespie and her 5th grade SPARKS students at St. Ann School
- Missy Ingles and her 3rd grade students at Jackson Elementary
- Bailey Station APEX - 4
This journal was brought to you by students at Bailey Station, Jackson Elementary and St. Ann Catholic School in the Memphis, TN area.
A Closer Look at… the Weddell Seal’s Whiskers
Let’s observe the whiskers on this seal. Describe what you see?
A closeup of a Weddell seal's whiskers.
From this picture you can see a number of things: color, location, number, length, organization and thickness etc. Do you notice any unique features? How do you think they would feel?
Here’s some of what I see:
- Color – Black or dark brown
- Location – On the tip of the snout – around the mouth and nose region. But wait… did you also notice the whiskers above the eyes – there are a few up there as well!
- Number –How many do you count? Don't forget the ones above the eye.
- Length – Notice the difference in length between the whiskers nearest the tip of the snout and those furthest from the tip. The lengths we've been measuring range between 6.5 cm and 11 cm - and we are taking 1 or 2 of the longest whiskers.
- Organization – They are in a straight line and about the same distance apart. Wow!
- Thickness – All the whiskers appear thicker than the surrounding hair. The thickest whiskers are the longest and furthest from the snout.
- Unique features – Some whiskers are curled on the ends, although this just happens in some cases; many seals have whiskers that are all straight. If you look closely you can also notice the shaft twisting.
Individual whiskers measuring about 8-8.5 cm. Look closely and you can see the twisting in the shaft.
Did you notice anything else?
Whiskers are impressive!
Whiskers – or vibrissae - are a very important sensory organ. Each whisker has many sensitive nerve fibers that can detect the slightest movements in the water. This helps the seal in two very important ways:
- To find food
- To move through ocean waters and sense water movement
Using its whiskers, a seal can detect the slightest vibrations in the water from passing prey, which makes this sense very handy when foraging, or searching, for food. And, in the dark depths of the ocean, or during the long dark winter months, Weddell seals can rely on this additional sense to guide them through the icy Antarctic waters. So, having these specialized vibrissae, or whiskers, is kind of like having an extra set of eyes or an additional sense of touch. What do you think it would be like if we had this extra sense?
What a great picture of a Weddell seal with flared whiskers. Photo Credit: Daniel Costa
What can we learn from whiskers?
You can learn a lot from a seal’s whiskers just by looking at the position of the whiskers – really! Just like cats and dogs, if the whiskers are close to the body then the seal is relaxed. But, if the whiskers are stiff and pointing outward – something has caught the seal’s attention and he may be ready to pounce on some lunch or protect his territory. However, Weddells mostly use their whiskers in the water – when they are hunting. Their time on the ice is mostly relaxed, so I haven’t gotten to see too much whisker action down here!
Check out this video from Dr. Terrie Williams to see for yourself: http://
Video Credit: Terrie M. Williams, In the Chill of the Night
Go Deeper!
From the scientist, Dr. Burns:
Weddell seals, as well as many other pinnipeds, have three different types of whiskers:
- Mystacial whiskers are located on the snout.
- Rhinal whiskers are located near the nose.
- Superciliary whiskers are located over the eyes.
Can you find the mystacial, rhinal, superciliary whiskers?
Whiskers grow and are shed just like hair. In some species, whiskers are shed each year (not all at the same time!), but in others they grow for several years. We think that Weddell seal whiskers are shed once a year, but we aren’t sure. As the whiskers are growing, they are incorporating isotopes and molecules from their diet, and we are collecting whiskers to look at changes in diet over time. Since whiskers take longer to grow out than hair, the diet record in the whisker covers a longer time period – with the signature at the base representing what was eaten most recently, and that at the tip the longest ago. That is why we try to take the longest whisker – but only one from each side – we don’t want to cause the seal any problems finding its prey in the dark!