miércoles, 29 de agosto de 2012

Whale Facts and Information


The term whale is a common name for several different types of marine mammals which include whales,dolphins and porpoises and make up what is known as the cetacean species.
While the term whale can sometimes refer to all cetaceans it usually excludes dolphins and porpoises.
The two primary  types of whales(suborders) include the Odontoceti (toothed whale) which includes both dolphins and porpoises, and whales such as the sperm whalekiller whalebeluga whale and narwhal whale, and the Mysticeti (baleen whale) which includes the humpback whale,bowhead whaleblue whale and minke whale among others.
All whales share several physical characteristics, they all have flippers designed for swimming, a tail with flukes used for navigating the water, and nasal openings (blowholes) for breathing.
Whale Facts: While whales currently inhibit the sea today their ancestors were once land dwelling animals. During the course of millions of years whales adapted to the ocean and eventually became inhabitants of the sea.

Endangered Whales

Whales as a whole inhibit the entire worlds oceans and have an estimated annual growth rate of about 3-13%.
It is currently estimated that there are over 80 different living species in existence today.
While there are currently over 1 millions whales living throughout the worlds oceans it is still difficult to accurately estimate their total population, and many of the species is now considered endangered.
In the past many of them were hunted for meat (a delicacy in some countries today) and raw materials (such as cooking oil, soaps, umbrellas and candles) which have left many whales endangered.
It wasn’t until the mid 20th century that whales stopped being hunted (in most countries) due to the possibility of extinction and the creation of alternative resources which eventually caused the whaling industry to decline.
However, even with the many efforts put into place (including the construction ofconservations) to protect the species there are still a few countries that hunt them for food and raw materials.
At the current moment people are considered the only primary predator to whales do to the fact that their large size and tough skin make them extremely difficult for most predators to successfully attack.
Whale Facts: Killer whales are known as apex predators. They are able to hunt other mammals without fear of being hunted or attacked themselves.

Migration (Mating and Feeding Season)

Whales have two primary seasons (with the exception of a few species) and will migrate between cold and warm climates during these two seasons.
These seasons are often refered to as feeding season and mating season.
During feeding months (the colder months of the year) whales eat a large variety of food.
Depending on the type of whale and where they live their diet can range greatly from small prey such as krillsquidfish and even birds to marine mammals such as sealssea lions and on very rare occasions other whales.
The types of food a whale eats isn’t necessarily determined by its size either.
For example the gray whale often eats small crustaceans and sea sediment, while the killer whale will attack and eat larger prey such as seals and other marine mammals.
During mating months (the warmer months of the year) some whales will forgo eating altogether, fasting and living strictly off of body fat and calories they consumed during feeding season.
Some whales can be very competitive during this time of the year and may even charge other male whales or horde female whales away in an attempt to mate and bear offspring with the female.
Males whales such as the humpback will also communicate by creating loud low-pitched melodic tones (also known as whale songs) and display their fitness andhealth by doing acrobatic stunts such as breaching and tail slapping which also helps show off their dominance and attract a female.
Whale Facts: Whales are known for making one of the longest migration trips of any animal and can travel as much as 5,000 miles or more from one destination to the other.

Breeding

In many cases whales don’t maintain fixed partners and can mate with several other whales over its lifetime to maximize its chances of reproducing offspring.
In order to feed a new-born whale the female will feed their young by producing a thick milk (about 35-50% fat) from her mammary glands and shooting it through the water and into her baby’s mouth.
The thickness of the milk allows it to travel through the water without breaking up containing vital nutrients for the baby whale.
The nursing and feeding period for baby whales can often be maintained for over a year.
In the context of a group or family males are often referred to as bulls, females are called cows and babies are commonly known as calves.
Whale Facts: Depending on the species of whale female whales can carry their young in their womb anywhere from 9-18 months before giving birth (also known as the gestation period).

Evolution

Whales are mammals and have evolved over the course of millions of years from land dwelling animals to inhabitants of the sea.
Before whales lived in the ocean they (actually their ancestors) walked and hunted on land.
Several characteristics point to the ancestral origin of whales including the need tobreathe air (unlike fish that have gills) despite living exclusively in the ocean, bones in their flippers which resemble limbs used for walking and hunting, and the vertical shape of their spines (more likely designed for running instead of swimming) as opposed the horizontal design and movement of fish.
Previous excavations have also dug up evidence of the whales evolutionary and physiological changes.
Ancestral bones show progressive cycles of change and transformation as whalesmoved from traveling on land to swimming in the oceans.
Whale Facts: The oldest relatives of Cetacea existed on earth over 50 million years ago. Dinosaurs became extinct 65 million years ago and the modern human is believed to have existed for 200,000 years.

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Anónimo dijo...

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