Whales

November 8, 2012 by  


whalesWhales are the largest animals. The largest whale is the giant blue whale which can reach lengths of 90-100 feet and weight as much as 120-150 tons.  The commonly seen finback whale is the second largest animal to ever appear on earth.

Whales are not fish.  They are in the same group as us–mammals meaning they breathe air, are warm-blooded, give birth to live children, and nurse their babies with milk just as female humans do.

The body of the whale is suited for marine life.  Their bones are soft and spongy, making them light in weight and not very strong for their size. (Isn’t that interesting, you would expect for an animal that big to be very strong.) The bones in a whale’s neck are fused together giving the neck support but, a whale is unable to turn its head.

Unlike humans the whale can’t see straight in front of them and they can’t see as well in the air as it can in water.  Whales have greasy tears that protect their eyes when they dive below 500 feet.

The whale can hear well in water even though it has no outside ears. Just as humans us their legs, arms and feet, whales use their flippers for balance and steering.   Instead of having a tail, a whale has a pair of flukes.  these are horizontal and move up and down as opposed to  fish whose fins move side to side.  The flukes serve as the whale’s propellers.

Whales breathe air and can stay under water between 10-15 minutes.  If a whale becomes frightened or wounded it an stay under water for more than an hour. When the whale comes back up to the top, it breathes or “spouts”.  This spout is carbon dioxide along with warm water vapor.  This breath (Similar to yours on a cold day) is like a water fountain.

Whales are very  sociable and usually travel in groups or school calles “gams” or “pods”.

The “toothed” whales are the largest group in terms of numbers: however they are smaller than the baleens.  these whales feed on fish and large sea animals.  a characteristic of the toothed whale is a single blowhole in the top of its head, instead two.  There is one type of toothed whale, the sperm whale, which can grow to a very big size.  Many legends have been written about this whale, such as Moby Dick.

The “baleens” are smaller in number but large in size than the toothed. These whales are characterized by having two blowholes and huge mouths.  The baleens feed by filtering food, called “krill”, through large sheets of tissue called baleens.  They swim with their mouths open which fill with water.  the krill is screened in as the water is forced out.  Krill growth depends on the seasons, because of this baleens will migrate to areas where the food supply is abundant.

Whales have few enemies other than man.  Men hunt whales for blubber to be make lamp oil.  Today, whales are hunted for such things as; making facial creams, cooking fat and explosives.  Although there has been a ban imposed on the killing of whales, people sometimes ignore the ban and continue to hunt and kill whales.

Cetaceans include the whales, dolphins and porpoises. There are over 75 species of Cetaceans. Whales belong to the order Cetacea (from the Greek word “ketos” which means whale),
Cetaceans have very strong social ties. The strongest social ties are between mother and calf. A social group of whales is called a pod. Baleen whales travel alone or in small pods. The toothed whales travel in large, sometimes stable pods. The toothed whales frequently hunt their prey in groups, migrate together, and share care of their young.

Cetaceans give birth to live young which are nourished with milk from their mothers – they don’t lay eggs. Cetaceans breed seasonally, usually in warm tropical waters, and females usually have one calf every 1-3 years. The gestation times range from 9-18 months. Whale calves can swim at or soon after birth. Mother whales care for their young for an extended period of time, usually at least a year, feeding them milk and protecting them.

Complex whales songs can be heard for miles under the water. The humpback’s song can last for 30 minutes. Baleen whales sing low-frequency songs; toothed whales emit whistles and clicks that they use for echolocation The songs are thought to be used in attracting mates, to keep track of offspring, and for the toothed whales, to locate prey.

Whales are very social creatures that travel in groups called “pods.” They use a variety of noises to communicate and socialize with each other. The three main types of sounds made by whales are clicks, whistles, and pulsed calls.

Clicks are believed to be for navigation and identifying physical surroundings. When the sound waves bounce off of an object, they return to the whale, allowing the whale to identify the shape of the object. Clicks can even help to differentiate between friendly creatures and predators. Clicks have also been observed during social interactions, suggesting they may also have a communicative function.

Whistles and pulsed calls are used during social activities. Pulsed calls are more frequent and sound like squeaks, screams, and squawks to the human ear. Differing vocal “dialects” have been found to exist between different pods within the same whale population. This is most likely so that whales can differentiate between whales within their pods and strangers.
Whales also use their tails and fins to make loud slapping noises on the surface of the water to communicate nonverbally. The sound can be heard for hundreds of meters below the surface and may be a warning sign of aggression or a tool to scare schools of fish together, making them an easier meal.

In the Stellwagen Bank National Marine Sanctuary, NOAA scientists attached sensors to whales in order to track their movement patterns. They hope to learn about the whales’ behavior and communication as well as to observe how human interaction affects their behavior.

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