Tuesday, December 15, 2009

Orca Whales / Killer of Whales

• An Odontoceti (toothed) mammal also known as the killer whale.
• Is largest member of the dolphin family, but mistakenly called one of the great whales because of its size.
• Found in all oceans of the world in “transient,” “resident,” and “offshore” family groups called pods.
• “Resident” pods have smaller home range and feed predominantly on fish.
• “Offshore” pods are smaller and seldom seen; little is known about them.
• “Transient” pods tend to travel over wider area and are occasionally seen off the Oregon coast, feed primarily on marine mammals, including juvenile Gray whales.
• Live in a matriarchal society, offspring living and traveling with mothers, sometimes after becoming fully grown.
• Individual pods often work together as teams to catch meals.
• Have well developed senses of hearing and vision, use echolocation, emitting high pitched clicks, bouncing sound off objects to locate prey, communicate with each other using clicks and whistles.
• Have a single blowhole near the top of the head, blow is a single, low bushy cloud.
• Teeth are large, enamel, conical shaped, and grow in both the upper and lower jaws.
• Upper body is mostly black with individually distinctive white patches behind eye and dorsal fin, underside is white (white patches and dorsal fin allow identification of individual whales); have a tall dorsal fin, measuring up to six feet in males and three feet in females.
• Mature males may grow to 28-30 feet and the female up to 26 feet.
• Males mature at about 12-16 years old, females at 6-10 years. Gestation is believed to last 15 to 18 months.
• Males live to 50-60 years, longer-lived females may live 80-90 years.
• Have no natural predators, whalers continue to hunt them, but not in large numbers.
• Susceptible to disease and interference of reproduction caused by pollution and chemical contamination. (San Juan residents listed as endangered because of high deaths attributed to pollution.)