The common name of my organism is "harbor seal". The scientific name is "Phoca Vitulina" , which is latin for "calf like seal". I chose this organism for this report simply because they're pretty animals.
Harbor seals have round spindle-shaped bodies thats covered by a coat of thick short hairs. Its color ranges from white with dark spots to black or brownn with white rings. Their dorsal surface is covered with more spots than the ventral surface. Harbor seals have rounded headswith fairly blunt noses. they do not have external ears. They have pointed and sharp teeth adapted for grasping and tearing their prey because they do not chew their food. Their back teeth are used to crush shells and crustaceans. All together they have 34 to 36 teeth. Another feature they have on their head is their Vibrissae. Vibrissaes are whiskers grown from the thick pads of a seal's upper lips. The functions are the same as a cat's. It grows continually throughout a seal's life. Male seals reach about 1.4 to 2.0 meter , weighing from 70 to 170 kg. Female seals reach about 1.2 to 1.7 meter , weighing up to 50 to 150 kg.
Classification
Kingdom: Animalia
Phylum: Chordater
Subphylum: Vertebrata
Class: Mammalia
Order: Carnivora
Family: Phocidae
Genus: Phoca
Species: Phoca Vitulina
Three organisms closely related to the harbor seal are Phoca Fasciata (ribbon seals) , Phoca Hispida (Ringed Seal) , and Phoca Largha (spotted seals).
Harbor seals reproduce sexually. Males mature sexually between the age of 3 to 7 and females between 2-6. Their mating season occurs from lat spring to fall. During this time , male seals may initiate by chasing , playfully biting and embracing females. The act of copulation takes place in the water. The gestation period (pregnacy) lasts between 9 to 11 months and usually one pup is born a year. Females come into estrus (heat) 6 weeks after they give birth. Pups are able to swim a couple of days after birth. Harbor seals' lifespan is usually 20 to 25 years. However , males tend to have a shorter life span from stress of fighting during breeding times.
Harbor seals are solitary animals. They do not like to be bothered by people or animals , especially when they haul-out. Reasons for going on land includes resting , thermoregulating , giving birth , nursing their young , molting , digestion , and protection from other preditors. While on land , adult individuals do not make physical contact with each other and responds to touching angrily. The younger seals interact along the edges of the group and stays away from the adults. When bothered , their aggression is shown by growling , snorting , and head thrusting. Vocalization occurs only when they feel threatened. While harbor seals are on land , they tend to stay in one location but remains alert for potential danger at all times. As harbor seals mature , they're behavior is less playful and less tolerant of close contact. Harbor seals can sleep on land or on water. In the water, their bodies are submerged exposing only their head for breathing. Their five main senses are eyesight, hearing, tactile, taste, and smell. Harbor seals have large eyes that are well adapted for underwater in dark and merky places. Underwater, their pupils dialate into a wide circle to allow as much light in as possible. On land, their eyesight are weaker. However, good eyesight isn't a major factor for survival. Scientist have found blind but heathly mother seals with pups at sea. Seals hearing, like eyesight, are well developed under water but are weaker on land. Harbor seals' tactile or sense of touch is very sensitive. They use their vibrissae to find food underwater. Vibrissaes are the whiskers attached to a seal's upper lip. Each vibrissae move independently in a sweeping motion transmiting tactile information from its nerves to the brain. Small vibrations caused by prey can be sensed by the seals. Little is known about the harbor seal's taste. Harbor seals have acute sense of smell, useful when identifying their pups.
Harbor seals' diet consist of squid, crustaceans, mollusks, and fish. Some of the fish they eat are rock fish, herring, flounder, salmon, hake, and sand lance. Their diet varies seasonally and regionally depending on what's more available. Harbor seals eat up to 5 to 6% of their body weigh per day. Thats 4.5 to 8.2 kg. Harbor seals do not chew they're food. They swallow it whole or in chunks. Different habitats provide different sources of diet.
Harbor seals inhabit shallow areas of esturaries, rivers, and places where sandbars and beaches are uncovered at low tide. These animals do not migrate regularly , but will travel in search of new feeding grounds. Harbor seal's population estimated to be about 100,000 in the Northern East Atlantic along the European coast from Finland to Portugual and coast of Iceland. Harbor seals can also be found in Canada, Long Island harbors, New York , and Florada. Harbor seals were not always found in North America. They had to migrate across the Atlantic river.
During the 1900s harbor seals were hunted as young as four weeks old for their fur. Another impact human had on seals were fishing competitions. Salmon hunters had caused harbor seals' population to decline and abandon their traditional haul outs. Marine debris including entangled nylon fishing nets or plastic materials can cause severe injury or drowning. Ingesting plastic can cause starvation. The bulky plastic in the seal's stomach sends a "full" signal to their brain , inhibiting normal eating.
One thing i found interesting about harbor seals is their abililty to dive and stay underwater. When they dive, their heart rate slows from 75-120 beats per minute to 4-6 beats per minute. Harbor seals have a greater volume of blood than a land mammal of same size, therefore they're able to retain more oxygen. The oxygen is stored in blood and muscle tissue rather than their lungs.
The basic needs of harbor seals are shallow water with an abundant source of food and an area for haul outs. They can be found by the coast of staten island and under the Verrazano bridge relaxing on a rock or eating a fish. They are not a high maintenance animal.
