From at least Cape Hatteras southward, the range of the Atlantic bottlenosed dolphins distributed in inshore areas may overlap with that of Atlantic spotted dolphins, particularly during the spring and summer, when the Atlantic spotted dolphins move inshore. There the two species may be confused. The Atlantic bottlenosed dolphins and the Atlantic spotted dolphins can be distinguished, however, by the following characteristics:
| Atlantic Bottlenosed Dolphin | Atlantic Spotted Dolphin |
|---|---|
| MAXIMUM SIZE | |
| 8 feet to as much as 12 feet(2.4 to 3.7 m). | 7.5-8 feet (2.3-2.4 m). |
| COLORATION | |
| Not spotted (old females mayhave spots on belly); darkgray on back; light gray onsides; white or pink on belly. | Dark purplish gray on back;lighter gray on sides andbelly; body becomes increasinglyspotted with age. |
| HEAD AND BEAK | |
| Head robust; beak relativelyshort. | Head more slender; beaklonger. |
Some Atlantic bottlenosed dolphins are distributed well offshore as far as the edge of the continental shelf. Those individuals may be confused with either rough-toothed dolphins (p. [135]) or with grampus (p. [96]). They may be distinguished from rough-toothed dolphins by the following:
| Atlantic Bottlenosed Dolphin | Rough-Toothed Dolphin |
|---|---|
| BODY COLOR | |
| Dark gray on back; lightgray on side; white or pink onbelly. | Dark gray, almost purplishwith yellow spots; lighter onbelly. |
| SNOUT | |
| Relatively short and stubby,and clearly demarcated fromforehead; usually all gray;some older individuals havewhite-tipped snouts and/orwhite lips. | Long and slender; notclearly demarcated fromforehead; lower jaw and lipsspeckled white. |
Distinguishing differences between the Atlantic bottlenosed dolphins in offshore areas and grampus are tabularized on p. [96].
In northeastern South America the range of the Atlantic bottlenosed dolphin apparently overlaps with that of the Guiana dolphin, which, except for size, it closely resembles (see p. [132]).
Distribution
The Atlantic bottlenosed dolphins are widely distributed in the temperate and tropical waters of the western North best known from New England southward to Florida, westward in the Gulf of Mexico, and thence throughout the West Indies and Caribbean to Venezuela.
In the northern portion of that range, Atlantic bottlenosed dolphins are distributed offshore. In the southern portions of their range from at least North Carolina southward, the majority are found nearshore and often enter bays and lagoons, and sometimes venture up the larger rivers. Daily migrations in these areas may follow tidal flow.
In these same southerly areas some Atlantic bottlenosed dolphins are distributed as far offshore as the edge of the continental shelf.