Harbor Porpoises
Diet:
In terms of diet, porpoises are known to consume fish squid and crustaceans as part of their primary food sources. To assist them with locating prey; porpoises hunt for food using echolocation. In addition to helping them find food, echolocation also helps them navigate the ocean in areas where light is absent, and also to keep track of other pod members. Although porpoises are predators they prefer to hunt in shallow coastal waters and usually hunt for food near or at the surface of the water. Due to the porpoises small size it requires frequent eating in order to maintain its energy and body heat as compared to some of the larger cetacean species that can reserve large amounts of energy which they store in their fat/blubber.
Communication:
Harbor Porpoises communicate using …show more content…
narrow band high frequency (NBHF) clicks in different patterns, kind of like a letter plus other letters can make a word. These clicks can reach sounds of up to 180 decibels, but can travel less than 1,000 meters underwater. So a group of harbor porpoises must stay reasonably close together to communicate. While they are aggressive, they will click faster and louder.
Social Structure:
Harbor Porpoises are less social, and tend to avoid interacting with humans or boats.
They prefer to live in groups of 10 or less, but during times of feeding and other social interactions can turn into groups of several hundred. They aren’t as energetic as dolphins when it comes to showing off, and are more reserved with their leaping and jumping. They also tend to say in a certain area, and generally do not leave their habitat for very long when they travel.
Predators:
Harbor porpoises are killed by their predators: killer whales and large sharks, like the great white shark. The biggest threat to harbor porpoises however is fishing nets. Every year porpoises die when they get stuck in fishing nets and cannot surface in order to breath. It is fascinating to hear that Harbor Porpoises in Europe, where there are no Killer Whales and large sharks, are apex predators. An apex predator is the predator at the top of the food chain with no predators. There are gruesome images of ravaged Harbor porpoises on Google and other media sites as well. The most common reason for this sickening sight is getting caught in nets and the rough netting scratching the porpoise’s
skin.
Reproduction:
Harbor porpoises can start reproducing at 3 years old for male or 4 years old for female. Males often compete for the right to mate with a female and go back to their way of living afterwards. The gestation period is around 11 months and the young can weigh up to 15 pounds when born. The young stay with the mother for a year and the mother is able to mate as soon as the calf leaves. The calf is born at around 30 to 35 inches long. The female calves are larger than males and grow and stay bigger than the males. Birthing peaks around June and July, but due to the shy nature of these porpoises it is hard to get exact data.
Location:
Harbor porpoises are found in shallow coastal waters of the North Atlantic, North Pacific, and Black Sea in temperate and subarctic waters colder than 60 degrees Fahrenheit. The harbor porpoise is protected under the Marine Mammal Protection Act of 1972. Europe is also requiring all EU Member States to protect the porpoises from all threats. It is the most stranded and sighted cetacean in European waters.
In terms of diet, porpoises are known to consume fish squid and crustaceans as part of their primary food sources. To assist them with locating prey; porpoises hunt for food using echolocation. In addition to helping them find food, echolocation also helps them navigate the ocean in areas where light is absent, and also to keep track of other pod members. Although porpoises are predators they prefer to hunt in shallow coastal waters and usually hunt for food near or at the surface of the water. Due to the porpoises small size it requires frequent eating in order to maintain its energy and body heat as compared to some of the larger cetacean species that can reserve large amounts of energy which they store in their fat/blubber.
Communication:
Harbor Porpoises communicate using …show more content…
narrow band high frequency (NBHF) clicks in different patterns, kind of like a letter plus other letters can make a word. These clicks can reach sounds of up to 180 decibels, but can travel less than 1,000 meters underwater. So a group of harbor porpoises must stay reasonably close together to communicate. While they are aggressive, they will click faster and louder.
Social Structure:
Harbor Porpoises are less social, and tend to avoid interacting with humans or boats.
They prefer to live in groups of 10 or less, but during times of feeding and other social interactions can turn into groups of several hundred. They aren’t as energetic as dolphins when it comes to showing off, and are more reserved with their leaping and jumping. They also tend to say in a certain area, and generally do not leave their habitat for very long when they travel.
Predators:
Harbor porpoises are killed by their predators: killer whales and large sharks, like the great white shark. The biggest threat to harbor porpoises however is fishing nets. Every year porpoises die when they get stuck in fishing nets and cannot surface in order to breath. It is fascinating to hear that Harbor Porpoises in Europe, where there are no Killer Whales and large sharks, are apex predators. An apex predator is the predator at the top of the food chain with no predators. There are gruesome images of ravaged Harbor porpoises on Google and other media sites as well. The most common reason for this sickening sight is getting caught in nets and the rough netting scratching the porpoise’s
skin.
Reproduction:
Harbor porpoises can start reproducing at 3 years old for male or 4 years old for female. Males often compete for the right to mate with a female and go back to their way of living afterwards. The gestation period is around 11 months and the young can weigh up to 15 pounds when born. The young stay with the mother for a year and the mother is able to mate as soon as the calf leaves. The calf is born at around 30 to 35 inches long. The female calves are larger than males and grow and stay bigger than the males. Birthing peaks around June and July, but due to the shy nature of these porpoises it is hard to get exact data.
Location:
Harbor porpoises are found in shallow coastal waters of the North Atlantic, North Pacific, and Black Sea in temperate and subarctic waters colder than 60 degrees Fahrenheit. The harbor porpoise is protected under the Marine Mammal Protection Act of 1972. Europe is also requiring all EU Member States to protect the porpoises from all threats. It is the most stranded and sighted cetacean in European waters.