ORCA WHALESDIET AND TEETH
Orcas are efficient hunters
that eat a very diverse diet of fish , squid , sharks ,
marine mammals (including whales and seals), turtles, octopi, and birds
(penguins and gulls). They have even been known to attack young blue whales and
other large whales. They have 10-13 pairs of large, interlocking conical,
enameled teeth distributed in BOTH the upper and lower jaws (for a total of 20
to 26 pairs, so the orca has from 40 to 52 teeth). The teeth curve inwards and
backwards - this helps the orca catch its prey. Teeth average about 3 inches
(7.6 cm) long and about 1 inch in diameter, but some are even longer. Members of
a pod frequently cooperate in hunts. An average-sized orca will eat 551 pounds
(250 kg) of food a day.
SOCIAL GROUPS
Orcas live in small pods of
6-40 whales; they are very social animals. The bonds between the close-knit
members of Orca pods are strong and last for life. The members of a pod hunt
together in a very sophisticated manner, attacking even very large prey and then
sharing it. The pod members protect the young, the sick and the injured.
DIVING, BREACHING, SPYHOPPING, AND TAIL
SLAPS
Orcas can dive to a depth of 100 feet (30 m) in order to
hunt. Orcas commonly breach (swim at very fast speeds toward the surface in
order to rise above the surface of the water and then fall back onto the
surface, splashing and making noise). Spyhopping (poking the head out of the
water to look around) and tail slapping are also common orca activities. The
purpose of these activities is unknown.
SPOUTING - BREATHING
Orcas breathe air at the
surface of the water through a blowhole located near the top of the head. Their
blow is a single, low bushy cloud.
SPEED
Orcas are very fast swimmers. They can swim
up to 30 mph (48 km) in bursts in order to catch prey.
VOCALIZATION
Orca vocalizations include clicks
used in echolocation, whistles, and scream-like pulses. The sounds are used to
communicate with other orcas, for mating purposes, and for locating prey.
Different pods (long-lasting groups of orcas) have distinctive "accents" and can
recognize members by this accent.
HABITAT AND
RANGE
Orcas whales live in waters ranging from tropical to arctic,
and both coastal and deep oceanic waters. They are found in all the world's
oceans and most of the seas. Orcas sometimes enter estuaries, but don't go far
from the sea.
HUMPBACK WHALESGENERAL DESCRIPTION
The humpback whale is a baleen whale and a rorqual whale that sings amazing songs. It performs complex and cooperative feeding techniques. The humpback has a bulky head with bumpy protuberances (tubercles), each with a bristle. Humpbacks are acrobats of the ocean, breaching and slapping the water. They live in pods and have 2 blowholes. The name humpback describes the motion it makes as it arches its back out of the water in preparation for a dive.
SIZE
Humpback whales grow to be about 52 feet (16 m) long, weighing 30-50 tons (27-45 tonnes). The females are slightly larger than males, as with all baleen whales. The four-chambered heart of the average humpback whale weighs about 430 pounds (195 kg) - about as much as three average adult human beings.
SKIN, SHAPE AND FINS
Humpbacks come in 4 different color schemes, ranging from white to gray to black to mottled. There are distinctive patches of white on underside of the flukes (tail). These markings are unique to each individual whale, like a fingerprint. The humpback's skin is frequently scarred and may have patches covered with barnacles.
Humpback whales have 14-35 throat grooves that run from the chin to the navel. These grooves allow their throat to expand during the huge intake of water during filter feeding. They have small, round bumps on the front of the head (called knobs or tubercles), edging the jaws.
Humpbacks have huge, mottled white flippers with rough edges that are up to one-third of its body length; these are the largest flippers of any whale. The humpback's genus, Megaptera, means "huge-wings," referring to its flippers. The flippers may have barnacles growing on them.
The deeply-notched flukes (tail) are up to 12 feet (3.7 m) wide. Humpbacks have a small dorsal fin toward the flukes.
DIET AND BALEEN
Humpback whales (like all baleen whales) are seasonal feeders and carnivores that filter feed tiny crustaceans (krill - mainly Euphausia superba, copepods, etc.), plankton, and small fish (including herring, mackerel, capelin, and sandeel) from the water. They are gulpers (not skimmers), filter feeders that alternatively swim then gulp a mouthful of plankton or fish. Concentrated masses of prey are preferable for this method of feeding. An average-sized humpback whale will eat 4,400-5,500 pounds (2000-2500 kg) of plankton, krill and small, schooling fish each day during the feeding season in cold waters (about 120 days). They eat twice a day.
Humpbacks cooperate in hunting and have developed a method of rounding up highly concentrated masses of prey that is called bubble-net feeding. The hunting members of a pod form a circle 10-100 feet (3.1-31 m) across and about 50 feet (15 m) under the water. Then the humpbacks blow a wall of bubbles as they swim to the surface in a spiral path. The cylindrical wall of bubbles makes the trapped krill, plankton, and/or small fish move to the surface of the water in a giant, concentrated mass. The humpbacks then eat a large, hearty meal.
The humpback whale has about 330 pairs of dark gray baleen plates with coarse gray bristles hanging from the jaws. They are about 25 inches (0.6 m) long and 13.5 inches (34 cm) wide.
SOCIAL GROUPS
Humpbacks travel in large, loose groups. Most associations between humpbacks are temporary, lasting at most a few days. The exception is the strong and lasting bond between mother and calves.
DIVING, BREACHING, SPYHOPPING, AND LOBTAILING
Humpback whales can dive for up to 30 minutes, but usually last only up to 15 minutes. Humpbacks can dive to a depth of 500-700 feet (150-210 m).
BLUE WHALESSIZE
Blue whales grow to be about 80 feet (25 m) long on average, weighing about 120 tons (109 tonnes). The largest specimen found was a female 94 feet (29 m) long weighing more 174 tons (158 tonnes). The females are larger than males, as with all baleen whales. The largest of the blue whales (150 tons) has a heart that weighs about 1,000 pounds (450 kg) and has 14,000 pounds (6,400 kg) of blood circulating in its body. The heart is about the size of a Volkswagon bug car. A human could crawl through the aorta (a major blood vessel).
SKIN, SHAPE AND FINS
The blue whale's skin is usually blue-gray with white-gray spots. The underbelly has brown, yellow, or gray specks. During the winter in cold waters, diatoms stick to the underbelly, giving it a yellow to silver- to sulfur-colored sheen; they are sometimes called "sulfur bottom."
They have a very small, falcate (sickle-shaped) dorsal fin that is located near the flukes (tail). Blue whales have long, thin flippers 8 feet long (2.4 m) and flukes that are 25 feet (7.6 m) wide.
DIET AND BALEEN
Blue whales (like all baleen whales) are seasonal feeders and carnivores that filter feed tiny crustaceans (krill, copepods, etc.), plankton, and small fish from the water. They are gulpers, filter feeders that alternatively swim then gulp a mouthful of plankton or fish - they lunge into dense groups of small sea organisms (krill or tiny fish) with an open mouth. 50 to 70 throat pleats allow the throat to expand a great deal, forming a gular pouch. The water is then forced through the baleen plates hanging from the upper jaw. The baleen catches the food, acting like a sieve.
The blue whale has about 320 pairs of black baleen plates with dark gray bristles in the blue whale's jaws. They are about 39 inches long (1 m), 21 inches wide (53 cm), and weigh 200 pounds (90 kg). The tongue weighs 4 tons (3.8 tonnes).
An average-sized blue whale will eat 2,000-9,000 pounds (900-4100 kg) of plankton each day during the summer feeding season in cold, arctic waters ( about 120 days).
