Animal Navigation is exactly what it sounds like: how animals navigate accurately without any maps, instruments, assistance. Many animals and insects travel thousands of miles each year to their respective breeding grounds without so much a a gas station attendant pointing them in the general direction. For me, I need a map to get to the coffee shop. I could find it without a map. I could, but not like a whale can find a safe warm water cove 2,321 miles away on the other side of the planet. Tomato, tomato, though. Right?
There are many mehcanisms animals use to navigate accurately. Animals like birds, wasps, and bees often used remembered landmarks. I use those, too. There must be more to it than just remembering a treee or a street sign, though.
The sun plays an important role for many animals on their travels. Fish, sea-turtles, and butterflies are a few animals that use sun compass orienation in transit. However, because the sun moves, this form of navigation requires a strict internal clock. Animals that navigate by the sun use this internal clock to maintain their circadian rhythm, which is a built-in and adjusted oscillation of about 24 hours. I sleep 5-8 hours each night. I need to get me one of them circadian rhythms, ya know?
Just as some animals navigate by the sun, others navigate by the night sky. The African dung beetle is a prime example, and it's been found that it can only navigate when the Milky Way or other clusters of stars are well lit. Sounds made up, I know. It's not. Star guidance was employed by our oldest descendants, and is still used widely across the planet. Not in L.A., though.
How does a blind mole rat navigate? Through magnetoreception, of course. Blind mole rats, also pigeons, are highly sensitive to the earth's magnetic field and use its charges to accurately negotiate their paths. I don't see well, so I often employ this mechanism. It hasn't served me like I'd hoped.
Someone once asked me, "C.M., do salmons have noses that can smell?" Well, the answer may be yes. It turns out, olfaction is what enables salmon to return to the exact rivers in which they were hatched. It is believed they use magnetic fields as well, but decipher between distinct water ways using their olfactory systems.
I'm interested in how humans have affected animal navigation. I imagine you have a lot more lost animals out there.
This has been today's topic. Hope you enjoyed. Thank you.