Showing posts with label whales. Show all posts
Showing posts with label whales. Show all posts

Whales Continue to Beach Themselves

Why do Whales beach themselves? The theory is that some coastal regions are shallow so sonar does not bounce back to the animals to tell them to keep away. This is only a theory. There seems to be no way of stopping the mammals from laying themselves on the sand to die a painful death. Dragging them out to sea is an attempt to save them, but they continue toward the beach again within hours.

A few days ago killer whales beached themselves on sandbars near Fraser Island. Three of them died. Fishermen have been told to keep their boats well away from the animals. They are trying to find deeper water. The hope is that open sea will attract them and they will move away from the shallow sand.

Apparently when a whale beaches, the whole pod panics. The presence of boats, particularly motorized ones, stresses them more. One would have thought that evolution would have "bred" out the beaching trait. The numbers who die each year on beaches is obviously not high enough to affect the breeding population so those with the trait pass it on to the next generation.

It is feared by many people that beaching could lead to extinction of species. There is no possibility of this as the number who swim safely along the coasts remains very large. It is good for people to try to save them. Unfortunately, humans cannot change nature.

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Australian Blog                         

Whales Sing a Different Song

It was believed that all whales spoke the same language like a bird species, for example, where all the birds have the same song. New observations show that whales sing different songs depending on where they live in the world.

Humpbacks on either side of the Indian Ocean do not sing the same song. Western Australian whales would not be able to "understand" whales in Madagascar. The two groups have been isolated from each other for a long time.

It would be expected that whales in the Northern Hemisphere and the Southern Hemisphere would differ, but the Indian Ocean whales are quite close to each other. The southern whales only have one similar song theme. A song is a series of themes.
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Dolphins Practice Whale-Talk at Night

Dolphins and whales are related. When dolphins are sleeping they show this. In the day they are quite unlike whales. Dolphins show off by jumping, swimming and catching balls. At night, however, they appear to "speak" a whale language.

The sounds they express closely resemble the humpback whale song. They only do this after they have heard the song. The song was in a soundtrack played during a performance for the public. This is an indication how all mammals deal with new things. The brain works on new things below the level of consciousness.

So well imitated were the whale sounds that tests done on them by volunteers showed people thought they were real whale sound. Dolphins mimic other types of sounds during the day, but they tend to zero in on whale sounds at night showing the evolutionary link.
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Whales Took an Evolutionary Leap Forward

Eons ago ancestors of whales made a major leap forward in evolution of their mouths. Whales living today can filter-feed in large amounts because the lower jaw is flexible in movement.

Ancient fossils such as Janjucetus hunderi do not have such a mobile lower jaw. The development of this attribute probably initially evolved to consume large living prey. It began with a wide upper jaw and normal teeth - no comb filters. Erich Fitzgerald from the Museum Victoria in Melbourne has created a family tree showing whale evolution.

The way whales feed is unique. It is believed that sucking when feeding still takes place, a left over from the days of the wide upper jaw.

A big question is why whales went back into the sea in the first place.
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