Ad

Bottlenose Dolphin (Tursiops truncatus)

Facebooktwittergoogle_plusredditpinterestlinkedintumblrmailFacebooktwittergoogle_plusredditpinterestlinkedintumblrmail

Get your copy of "Albert the Orca Teaches Echolocation to The Super Fins" beginning March 2017 at TheSuperFins.com.
Get your copy of “Albert the Orca Teaches Echolocation to The Super Fins” beginning March 2017 at TheSuperFins.com.

The bottlenose dolphin is one of the most well known species of marine mammals. They have a robust body and a short, thick beak. Their coloration ranges from light gray to black with lighter coloration on the belly. Inshore and offshore individuals vary in color and size. Inshore animals are smaller and lighter in color, while offshore animals are larger, darker in coloration and have smaller flippers. Bottlenose dolphins can sometimes be confused with the rough-toothed dolphins, Risso’s dolphins, and Atlantic spotted dolphins in regions of overlapping distributions.

Bottlenose dolphins range in lengths from 6.0 to 12.5 ft (1.8 to 3.8 m) with males slightly larger than females. Adults weight from 300-1400 lbs (136-635 kg). This is a long-lived dolphin species with a lifespan of 40-45 years for males and more than 50 years for females.

Bottlenose dolphins are commonly found in groups of 2 to 15 individuals. Offshore herds sometimes have several hundred individuals. This species is often associated with pilot whales and other cetacean species.

Bottlenose dolphins are generalists and feed on a variety of prey items “endemic” to their habitat, foraging individually and cooperatively. Like other dolphins, bottlenose dolphins use high frequency echolocation to locate and capture prey. Coastal animals prey on “benthic” invertebrates and fish, and offshore animals feed on pelagic squid and fish. Bottlenose dolphins employ multiple feeding strategies, including “fish whacking,” where they strike a fish with their flukes and knock it out of the water.

Sexual maturity varies by population and ranges from 5-13 years for females and 9-14 years for males. Calves are born after a 12 month gestation period and are weaned at 18 to 20 months. On average, calving occurs every 3 to 6 years. Females as old as 45 years have given birth.

This species is classified as LEAST CONCERN according to the IUCN's Red List.
This species is classified as LEAST CONCERN according to the IUCN’s Red List.

Status

MMPA Depleted – Western North Atlantic Coastal stock
CITES Appendix II – throughout its range

Species Description

Weight:
300-1400 lbs (135-635 kg)
Length:
6.0-12.5 ft (~2-4 m)
Appearance:
light gray to black
Lifespan:
40-50 years; sexual maturity varies by population but ranges from 5-14 years of age
Diet:
invertebrates, squids, fishes
Behavior:
use high frequency echolocation to locate and capture prey; use multiple feeding strategies, including “fish whacking,” where they strike a fish with their flukes and knock it out of the water

RELATIVE SPECIES: Indo-Pacific bottlenose dolphin, Rough-toothed, Pantropical spotted dolphin, Atlantic Spotted Dolphin

NEIGHBORING SPECIES: Indo-Pacific bottlenose dolphin, Rough-toothed, Pantropical spotted dolphin, Atlantic Spotted Dolphin, Spinner Dolphin

PREDATORS: Humans, Sharks

THREATS: Injury or mortality from fishing gear and ships, pollution, habitat degradation, catch in Japan.

DIET: Fish and squid

MANNER OF FEEDING: Herding large schools of fish with other dolphins, foraging in substrate, following shrimp and fishing boats to catch anything that is left behind. Whack fish with their flukes to knock it out of the water.

BEHAVIOR: Travel in groups of 15 or so, but may be found in groups of hundreds. Are seen with other species of dolphins. Can be aggressive with other dolphin species. Females travel together for protection from males, raising calves and social learning. Males will form alliances with other males in order to gain access to females. Very intelligent and playful. Will leap out of the water, play with fish and seaweed, ride wakes from ships. Will often attack other dolphin species that try to ride their wakes. Very curious and social, like to approach ships.

REPRODUCTION: Become sexually mature at 5-14 years. Gestation is 12 months. Calves stay with their mothers for multiple years. Calves are born every 3-6 years. Calves are usually raised by a whole pod of females.

LIFE SPAN: At least 50 years

Habitat

Bottlenose dolphins are found in temperate and tropical waters around the world. There are coastal populations that migrate into bays, estuaries and river mouths as well as offshore populations that inhabit pelagic waters along the continental shelf.

Distribution

The bottlenose dolphin has a worldwide distribution ranging from latitudes of 45°N to 45°S.

Population Trends

Our Stock Assessment Reports (SARs) for bottlenose dolphins include estimated population sizes for U.S. stocks, though population trends for all of the U.S. stocks are currently unknown.

Threats

  • incidental injury and mortality from fishing gear, such as gillnet, seine, trawl, and longline commercial and recreational operations
  • exposure to pollutants and biotoxins
  • viral outbreaks
  • direct harvest, in Japan and Taiwan

Conservation Efforts

NOAA and its local, state and federal partners started the Barataria Bay dolphin study in 2011 as part of theNatural Resource Damage Assessment (NRDA), the process for studying the effects of the Deepwater Horizon oil spill.

In 2006, NMFS implemented the Bottlenose Dolphin Take Reduction Plan (BDTRP) to reduce the serious injury and mortality of Western North Atlantic coastal bottlenose dolphins incidental to nine U.S. commercial fisheries. In addition to multiple non-regulatory provisions for research and education, the BDTRP requires modifications of fishing practices for small, medium, and large-mesh gillnet fisheries from New York to Florida. The BDTRP also established seasonal closures for certain commercial fisheries in state waters.

Bottlenose dolphins are classified as Data Deficient on the IUCN Red List This link is an external site..

Regulatory Overview

This species is protected under the Marine Mammal Protection Act (MMPA) of 1972, as amended. The Western North Atlantic Coastal stock of bottlenose dolphins is listed as “depleted” under the MMPA. In addition, NMFS has classified five U.S. stocks of bottlenose dolphins as “strategic” stocks: Eastern Gulf of Mexico Coastal; Western Gulf of Mexico Coastal; Northern Gulf of Mexico Coastal; Gulf of Mexico Bay, Sound and Estuarine; and Western North Atlantic Coastal.

Taxonomy

Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Cetacea
Family: Delphinidae
Genus: Tursiops
Species: truncatus

Cool/Gross/Weird:

-TSF-

From NOAA

 
Facebooktwittergoogle_plusredditpinterestlinkedintumblrmailFacebooktwittergoogle_plusredditpinterestlinkedintumblrmail

FacebooktwitterpinterestFacebooktwitterpinterest