It is very unusual for me to watch this TV programme as to be honest I don’t like it much but this evening they had a piece on eels. Apparently they are chipping eels so that they can track them on the way to the Sargasso Sea.
Now I have always been very interested in eels and their life cycle. Amazingly it seems that every day they go down into the deepest water and then at night they come back towards the surface. So as well as swimming all the way to the Sargasso they swim up and down in the water column as much as a kilometre a day just going vertically up and down! They did not know why they do this and I have a theory, probably rubbish but who knows. Maybe they swim up to navigate by the stars when they feel safe.
Sounds unlikely I know but I have just looked at bird migration and a number of birds migrate mostly at night.
An extract is here “Also during the 1950’s, the German Franz Sauer did a similar experiment with birds who could and
could not see the night stars. The results were the same: Certain species can orient themselves according to the sky’s
major stars. In fact, an experiment with Mallard Ducks found that if the moon is so bright that important stars are hidden
by glare, released ducks can’t orient themselves as well as on darker, moonless nights.”
Another quote “At least one species of birds — Indigo Buntings — use the stars to navigate at night. It appears that
they learn to recognize the pattern of stars in the night sky when they are still in the nest. For instance, a few years
ago, a study found that nestling Indigo Buntings in the northern hemisphere watch as the stars in the night sky wheel
around Polaris — the north star, located above Earth’s north pole. Polaris lies due north for those in the northern
hemisphere. Being able to identify Polaris in the night sky could help birds find their way north. “
Anyone else see the programme and have any views? I only saw that bit and left the room when Peter Andre appeared!
TF_billy the squid.
