Dolphins were thought by ancient Greeks and Romans to bring mariners good luck, and appeared frequently in their legends. In fact, the Greeks honored them on more than 40 coins.

Thanks to their graceful beauty, intelligence, acrobatics and playful nature, bottlenose dolphins have fascinated people since ancient times. Streamlined and smooth, their bodies reach varying lengths from 6 to 12 feet, dependent upon geographic location. Females can live for more than 50 years, while males typically live for about 40 years.

Bottlenose dolphins produce several sounds, including whistles, clicks used for echolocation, and squawks. Their "signature whistles" are individually distinct and are probably used to communicate the dolphin's identity, location, and emotional state.

Habitat & Diet

Found primarily in the temperate and tropical oceans of the world, bottlenose dolphins tend to be coastal dwellers, but they can adapt to a variety of marine and estuarine habitats.

They feed mostly on bottom-dwelling fish and squid. Adult males feed farthest from shore, while adolescents and females with their calves typically feed nearer the shore.

Social Organization

Social interaction is an important part of life for bottlenose dolphins, as it is for their cousins, the great whales. Dolphins typically form groups of from two to 15 individuals. The structure of these social groups varies widely with regard to sex, age, familial relationships, and affiliation histories. Smaller groups tend to frequent near-shore waters, whereas larger groups form in offshore waters.

Reproduction

After a gestation period of about one year, females give birth to live calves, which they may nurse for up to two years. The interval between births is usually from three to six years.

Females reach sexual and physical maturity between five and 13 years of age, long before their male counterparts. Males reach sexual maturity at between nine and 14 years, but they are not fully physically mature until their late teens. Most breeding males are at least 20 years old.

Threats to Bottlenose Dolphins

While fishing for dolphins still occurs in some parts of the world, such as Peru, Sri Lanka, and Japan, most countries have outlawed the practice. Nonetheless, dolphins are stilled killed incidentally in other fisheries-including tuna, sardines, and anchovies.

Some bottlenose dolphin populations have declined as a result of pollution and habitat alteration. Dolphins are known to accumulate contaminants in their tissues, which may affect dolphins' ability to reproduce and contribute to higher infant mortality. Because many dolphin populations frequent near-shore areas, they are particularly vulnerable to entanglement in fishing gear and boat collisions.