Have you ever wondered how animals that live near Earth’s North and South Poles survive? What do they eat, and how can any kind of food chain exist? The answer to this is ice algae.
Unlike most plants, algae do not have flowers, roots, stems, leaves, or vascular tissue. However, ice algae, like most plants, provide the starting point for a food chain. In this case, it is a food chain in very cold places. Tiny krill, penguins, seals, polar bears, and blue whales all depend on ice algae to survive. In 2016 Dr. Thomas Brown of the Scottish Association for Marine Science studied polar bears and found that 86% of the polar bears’ nutrition came from a food chain that originated with ice algae.
Ice algae have chlorophyll so they can use whatever light is available for photosynthesis. There are a variety of types of algae that live in different conditions. Some live on the surface of the ocean, some on the floor of the ocean, and some in or on the ice itself. Ice algae produce fatty acids which supply nutritional value for animals that live in what would otherwise be a nutritional void. Because there is ice algae, animal life is abundant under, in, and around the ice at both poles.
Have you ever wondered how cats can navigate in a dark room? Dr. Hendrick Van der Loos is an expert on the role of whiskers in animals. His research team at the University of Lausanne in Switzerland has shown an amazing demonstration of what cats can do by seeing with whiskers.
They blindfold cats and put them in a room with toys and other obstacles scattered around. The cats could navigate the room as well as cats with full sight because of their whiskers. The ancient Egyptians believed that cats had mysterious powers because they observed cats hunting mice in complete darkness.
We now know that not only cats but also walruses, pigs, seals, moles, and even whip-poor-wills have whiskers designed to meet their specific needs. The secret in all of these animals is that they possess specialized touch-sensitive hairs called vibrissae which are embedded deeply in the skin and resting in tiny sacs of fluid which pivot like a straw in a bottle of soda-pop. Brushing a whisker generates an electric signal in the fluid which is surrounded by nerves. The nerves feed the signal to the brain. This system is so sensitive that animals can detect the change of air currents around an object. They are seeing with whiskers which serve essentially as a tactile third eye.
A blindfolded cat can catch and kill a mouse. High-speed photography shows that a cat on the prowl for a mouse holds its whiskers in a fan-shaped pattern. Just before pouncing, the cat shifts its whiskers forward around its mouth. When the cat makes contact with the mouse, the whiskers tell the cat which way the mouse is dodging. As the whiskers wrap around the mouse, the cat can detect ahead of time which direction the mouse is trying to go.
A walrus will cruise around the floor of the ocean with its rump up and its head down stirring up the sea floor, so sight is useless. The walrus roots through the clouded water sorting out anything that might be good to eat by seeing with whiskers. Since walruses feed at night, there is the added benefit of being able to eat 24 hours a day. Moles have whiskers around their feet and tails which can detect insects in total darkness underground. Whip-poor-wills, nighthawks, and nightjars have whiskers near their beaks and are active after dark.