Millennium Post

Are big brains smarter?

Are big brains smarter?
There is some evidence that people with larger brains are more intelligent than those with smaller brains, at least as measured by IQ tests. Do humans, then, have the largest brains?
Our brains are bigger than other apes, weighing between 1.25-1.45 kilos. Our brain comprises about 2 percent of our body mass but consumes some 25 percent of our energy. Yet, we do not have the biggest brains on Earth. Elephant brains can weigh over 4 kilograms, and whales have much larger brains still, weighing up to 9 kilograms. A bottlenose dolphin has a much larger brain as do whales.
 If the idea is to see the brain size relative to the body size even then we lose out to other animals. Some shrews and mice, it turns out, have brains that are up to five times larger than ours relative to body size. Their brain can be an extraordinary 10 percent of their body, compared to our 2 percent.
So perhaps it is less to do with size and more to do with how it functions.

What should I avoid if I want to see birds closer? I really do want to be friendly with the crows that come to my house.
A: Obviously behaving calmly quietly and moving slowly is a prerequisite. Crows pay a lot of attention to eyes. If you walk towards crows as they feed on the ground, and if you keep your eyes averted to the side, you will be able to get at least 3 feet closer before they react to your presence. 

If you stare at them, they will fly away. If you look at even one crow in the flock, that crow will remove itself. Remember, crows recognise faces and remember your past deeds. Crows keep a careful eye on the people that pass them by, and they ascertain what our intentions may be from our subtle behaviours and glances.

 A stare is a signal of threat for most animals. Aggressive and fearful birds stare more and blink less at their flock mates than do passive birds.

Does pet ownership actually have any effect on the health of the owner?
A: Thousands of studies have said that pet owners are less likely to die of heart attacks as quickly as non pet owners. They are less likely to get depression or heart disease.

The benefits of pet ownership have been demonstrated on many different types of “hard” health outcomes, including laboratory measures, such as triglycerides, blood pressure and heart rate variability, adherence to cardiac rehabilitation programmes, and mortality from cardiac events and strokes.

 Studies show that “dog owners were 50 per cent more likely to achieve the nationally recommended 3 hours per week of exercise.” In addition, many experimental studies have found that presence of pets reduce blood pressure and heart rate when experimental participants are exposed to stressors such as mental arithmetic, putting one’s hand in ice water, or making a speech.

 Why do dogs shake themselves so vigorously after a bath? I towel him down but it makes no difference.
A: Scientists at Georgia University have found that a dog can shake nearly 70 percent of the water from its fur in about 4 seconds. This shaking is done by many other species – 16 were studied including mice, dogs, tigers and bears. Why did it evolve in furry animals? If it crossed a stream or got caught in the rain it is critical that it dry off because water destroys the insulation properties of fur and the animal would die of hypothermia. 

Suppose there was no sun that day to evaporate the water, the animal would have to use its own body head to warm the air and do the evaporation. And that would take a large amount of energy - a wet 120 kg. dog, with 2 kg. of water in its fur, would use 20 percent of its daily caloric intake simply to air-dry. In contrast, the shaking mechanism is a highly energy-efficient way of getting dry quickly. The larger the animal the slower its shaking oscillations to achieve the same effect of throwing water off from the body. Researchers found that a Labrador retriever shakes at a rate of 4.5 Hz (Hz is a measure of cycles per second), while a Chihuahua shakes at 6.8 Hz. The research group found that a mouse must shake at 29 Hz, while a brown bear need only shake at a rate of 4 Hz to dry off.

Are dogs, like people, left or right handed? And does it make a difference to their personality?
A. Dogs have three groups – those who have no preference at all, those with left and right paw preferences. The only personality difference that scientists have found – or claim to have found – is that left paw dogs are more aggressive than the other two kinds.

Is birdsong music?
A: Some of it may well be, if the bird is happy, well fed and is wooing a mate. But for the most 
part it is just humans projecting their own preferences onto the bird. Just because the notes are beautiful, that does not make them music. They are simply language, one bird talking to another.

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