"Look! Dolphins!" When someone utters this familiar call, it turns nearly every head on the beach. Many of us have spent hours scouring the waves offshore for a glimpse of dark fins leaping from the water, a telltale sign that dolphins are near. What a delight these wave jumpers are to watch.

But, are we watching dolphins or porpoises? Are they the same? According to marine biologists, there is a difference. Only two of the world's six porpoise species live in U.S. waters, and they have blunt heads and triangular dorsal fins. Dolphins on the other hand, have a beak and a curved dorsal fin, and there are more than thirty species living in the world's oceans.

The Atlantic Bottle-nosed Dolphin, an inhabitant of shallow coastal waters, bays and tidal rivers is the species most commonly found in Virginia waters. It is the one most often seen by beachgoers and the one made famous by television's "Flipper." Its common name comes from its rounded snout or "beak" which resembles a bottle.

Dolphins are actually small whales, related to sperm whales, killer whales, narwhals and other species of toothed whales. They are also mammals and must come to the surface to breathe, which they accomplish through a single blowhole on the top of their head. They often travel together in social groups called pods; these can be as few as five animals or number in the hundreds.

Although small by comparison with other whales, bottle-nosed dolphins can grow seven to ten feet long as adults and weigh as much as five hundred pounds. They are dark on top and light on the bottom, coloration that provides excellent camouflage from above and below. Because they spend time at the surface and underwater, their eyes work well both in and out of the water. But while having good eyesight is helpful, dolphins also rely on another tool to avoid underwater obstacles, find food, and identify each other - echolocation.

Highly intelligent and vocal animals, dolphins emit a wide variety of sounds, most coming from their blowhole and some of which are ultrasonic. By making clicking noises, they send out sound waves that bounce off of objects then return to be picked up by the dolphin's bulbous forehead. This is particularly helpful at night or in cloudy waters. Dolphins use a complicated system of whistles, squeaks, trills and other sounds to communicate with each other, too.

Fish is a primary source of food for dolphins, and they may eat as much as 13 to 14 pounds a day, and twenty pounds or more in colder waters. Schooling fish like mackerel, herring, and menhaden are food choices, although they will feed on almost any species of fish as well as squid or octopi. Besides food, fish also provide another necessary staple of life for dolphins - water. They cannot drink or process saltwater, so dolphins get the fresh water they need to live from the food they eat.

Watch dolphins long enough and you soon learn how acrobatic and graceful they are. They often leap high into the air and dive or fall on their backs in the water. They also hitch rides on the bow waves of boats, sometimes riding for hours. They are excellent swimmers and can reach maximum speeds of 35 miles per hour. Their flexible smooth skin can be adjusted to reduce resistance during swimming, helping them gain speed. Moving the tail up and down provides the propulsion while flippers help with balance and steering. They can also dive quite deep and stay submerged for several minutes.

Sharks and barracudas are the only ocean predators on dolphins, although even sharks will usually leave them alone. Dolphins have been known to kill sharks by butting them with their snouts. Human endeavors present dolphins with more serious hazards. They are hunted for food in many coastal countries, get trapped in fishing nets, particularly gill nets, collide with boats and fall victim to pollution.

Whether you're on the beach at Assateague Island, boating in the Chesapeake Bay, or even crossing the Chesapeake Bay Bridge Tunnel, keep your eyes open for these wonderful wave junipers. You, too, may get to be the one to call out those magical words, *Look! Dolphins!"

Nancy Biegel
Outdoor Recreation Planner, ESVNWR