Species: Bottlenose Dolphin (Tursiops truncatus)

Use: N/A   

Authors: Ann Charity Weaver

Methods: N/A

Publications/Presentations: Thesis presentation (1987); Mueller, M., Boutiere, H., Weaver, A., & Heut, N. 1998. Ethogram of the bottlenose dolphin with special reference to solitary and sociable dolphins. Vie et Milieu 48, 89-104.

Aerial behavior

Bow: An airborne ascent followed by reentry within one body length from the point of exit. The animal moves into the air in a dorsal position from an accelerated swim and assumes a concave arch at the highest point of elevation. In descent, the tailstock remains relatively stationary as the foresection moves down or the tailstock moves up as the foresection remains relatively stationary; the long axis is straight at reentry but has a pronounced concave arch while airborne.

Headup: Exposure of the foresection at the surface in a near vertical or vertical position. The animal is briefly stationary at the surface with a pronounced arch along the axis and exposes the body to the gape or pectoral fins. The jaws may be held open.

Lateral bow: A bow performed in a lateral position. The animal may either emerge from the water in a lateral position or dorsal position. From the dorsal position, the animal rotates along the axis to the lateral position.

Unison bow: A bow is performed by two or more animals in unison.

Breach: The animal elevates a portion of the foresection above the surface and drops it flatly and noisily on the lateral side. The body is often slightly arched and at an oblique angle; the airborne animal may rotate in the long axis, which orients the lateral side of the body down. Pectoral fins extend out and form right angles to the long axis while parallel to the dorsal fin. Some portion of the tailstock retains contact with the water.

Back breach: The foresection is elevated above the surface with the ventrum uppermost and dropped backward, land noisily on the dorsum.

Leap: Airborne forward progress of at least one body length while in the dorsal position. It should be noted that repetitive instances of Leaping are referred to as Porpoising.

Inverted leap: Performance of a leap in the inverted position.

Lateral leap: Performance of a leap in a lateral position.

Wave leaping: Sudden airborne emergence from the back of a wave by an animal facing offshore.

Arches

Body thrust: Rapid, alternate convex and concave arches from a dorsal position at the surface or interface. The rostrum is oriented downward and the body is made repeatedly taut without forward progress.

Caudal arch: Exposure of the fluked by an upward curve of the tailstock by a submerged animal in a lateral position.

Dorsal arch: Brief upward movement of the dorsal fin by an animal in a dorsal position. The foresection and caudal section are drawn downward and inward.

Lateral arch: Powerful sideways lunging of a highly arched animal at the interface in the lateral position conspicuously exposing a side position of the white ventrum. The animal appears abruptly at the surface with one side up or rotates from the dorsal position. This active behavior involves splashing and often occurs repetitively among animals in proximity of one another. The behavior is often repeated and is usually seen during sexual activity.

Stretch: A brief elongation of the body along the long axis by a stationary animal in the dorsal position. Brief extension of the head and tailstock creates a slight convex arch.

Vertical arch: A poised posture at the surface by a head-up vertical animal exposing the foresection. The melon and dorsal fin extend up while the ribsection appears sunken in a slight convex arch; the rostrum is pulled toward the body by a bend at the neck. The behavior may be repeated.

Contact behavior

Kelp dragging: Strands of kelp are hooked around the front of the dorsal fin and trail off either side of the body as the animal makes forward progress at the interface.

Rostral nudge: The tip of the rostrum touches the body surface of a second animal briefly or repetitively. Both animals are submerged in the dorsal position while making a forward progress. The animal that initiates contact may orient obliquely to the second animal.

Rubbing: The drawing of some portion of the body along another surface so that contact between the two surfaces is smooth and steady.

Formations

Spoke formation: A number of animals oriented toward the middle forma  circle that may surround an individual.

Cluster formation: Different headfirst orientations of subgroups and individuals that ate dispersed or in loose proximity.

Diamond formation: Head-to-tail orientation of line-abreast subgroups such that middle subgroups contain more animals than the front and back subgroups. This formation can involve members of one or more subgroups.

Echelon formation: maintenance of a position by one animal slightly behind and below the dorsal fin of another. The animals are parallel and face the same direction. This behavior involves 2 or more individuals.

Long formation: Columnar, head-to-tail orientation of several animals.

Milling: Continual change of headfirst orientation and moderately active swimming and steep diving by individuals in proximity to one another. All remain in the specific area.

Rank formation: Linear headfirst alignment by animals that are side-by-side and facing the same direction.

Dispersed rank: Two or more subgroups in loose or dispersed proximity to one another, which form a long, circular or oval pattern.

Staggered rank: Incomplete headfirst alignment by several side-by-side animals. Distances between individuals vary within loose proximity.

Wave making: A crest of water is pushed ahead of several submerged individuals in a rank, which may move in any direction.

Wide formation: Three or more animal in rank position separated more than two body lengths from each other.

Head movements

Chin up: Brief exposure of the rostrum above the surface at variable upward angles by an elevation of the head. The animal surfaces with the rostrum elevated or raises it after reaching the surface. The long axis is generally straight and at an oblique angle; the dorsal fin is elevated and exposed only during pronounced performances.

Fish toss: An animal with a fish in its mouth emerges at the surface in a headup vertical position. The fish is thrown by a sideways or backward cocking of the head.

Glance: Brief exposure of the eye above the surface by a stationary or mobile animal in the dorsal position. The animal may elevate the eye by a slight rotation of the long axis or by pulling the rostrum down and back by a bend at the neck.

Head nod: An up-and -down head movement performed by an animal in the dorsal position. The head movement in articulated from a bend in the neck and may be performed at any water level. At the surface the behavior may be repeated; fully submerged animals may perform a single nod.

Head pullback: A smooth, localized head motion that arches the melon and rostrum backward and upward slightly. This behavior usually occurs upon surfacing and may function to raise the blowhole above the water.

Head shake: Alternate side-to-side movements of the head that occurs in all water levels and with varying degrees of exaggeration. The head clears the water briefly and the chin is elevated by animals at the surface; submerged animal exhibit single or briefly repetitive lateral movements in either or both direction(s) at slower swim speeds.

Head thrust: An abrupt, backward and upward pulling of the head that straightens the arch of the long axis.

Spy hop: Brief vertical or near-vertical elevation of the body and head-up exposure of the foresection followed by a sinking return to the water. Pectoral fins generally extend out at right angles to the long axis. The head may be angled down from the ribsection by a bend at the neck or the animal may rotate briefly along the long axis. Rarely, the animal may make forward progress in a bobbing motion with the head angled down from the neck.

Pectoral fin movement

Pectoral extension: Exposure of a pectoral fin at the surface by an animal in the lateral position. The fin angles obliquely from the long axis and the animal generally remains stationary at the interface.

Pectoral parallel extension: Exposure of both pectoral fins by an animal in the ventral position at the interface. The fins extend out at right angles to the long axis. The behavior can occur at varying water levels and the animal may make some forward progress.

Pectoral flex: Rapid up-and-down and/or side-to-side movements of a pectoral fin exposed at the surface.

Respiration

Chuffing: Abrupt release of air that sounds like a course, wheezy 'chu'. Fine vapor may rise in a cone shape up to 1 m overhead.

Squeeze breath: Audible and brief expulsion of air from the blowhole that sounds like air escaping the tightened neck of a balloon. Squeeze breaths rarely occur with visible vapor.

Subsurface exhalation: The release of air by a submerged animal, which forms either a stream of fine bubbles or one or two large bubbles.

Vaporous breath: Surface exhalation resulting in a cone of mist while the animal is in a dorsal position. Exhalation is audible and the mist may ascend as much as 1 m in the air.

Silent vaporous breath: Soundless exhalation accompanied by a mist.

Slaps

Chin slap: A raising and lowering of the rostrum in the dorsal position, striking it flatly and noisily against the surface. The rostrum is barely raised at low intensities; high intensity chin slaps are characterized by a high elevation of the foresection and nearly complete submergence of the dorsal fin upon contact. This behavior is performed by both adult and juvenile animals.

Dorsal fin slap: Flat contact between the broadside of the dorsal fin and the water surface. The animal rotates along the long axis in either direction in the dorsal position.

Head slap: The side of the head makes sharp, noisy contact with the surface. The exposed head is cocked sideways by a rotation of the body or starts in the lateral position. The animal may pause before striking, and extended pectoral fins angle back.

Back head slap: Flat and forcible contact between the blowhole region and the water surface by an abrupt backward thrust of the head. The animal moves from a dorsal position to a head-up, near-vertical position before dropping the head back.

Pectoral fin slap: Noisy, rapid and repetitive contact between the pectoral fin and the water surface made by an animal in the lateral position.

Tail slap: Flat and noisy contact of the caudal section on the water surface. The animal in the dorsal position at the interface may pivot the flukes up, or raise the entire tailstock over the surface, The flukes occasionally flex briefly during the downswing and often curve across their width. The foresection is often submerged and slaps may be repeated.

Inverted tail slap: The dorsal side of the flukes is brought down flatly on the water surface by an animal in the inverted position. This behavior may be repeated and can occur while the animal is stationary or making forward progress.

Motorboating: A series of rapid and repetitive tail slaps during forward progress by the animal in the dorsal or inverted position at the interface.

Stationary behavior

Floating: A stationary position at the interface exposing the foresection of the animal in a pronounced concave arch. The blowhole area is conspicuously rounded as if the head was strongly bent down. The rostrum and tailstock are not exposed; the leading edge if the dorsal fin may be visible. This behavior is exhibited by individuals, pairs or groups and can occur for long durations. The behavior is often repeated and is usually peripheral to sexual activity.

Ventral float: Animal is stationary at the water surface in a ventral position with a pronounced arch along the long axis. The head is exposed vertically up to the gape and the tips of both caudal lobes are exposed.

Lean: A slight rotation along the long axis from the dorsal position that moves the animal toward the lateral position and which is held briefly. The behavior is often repeated and is usually seen during sexual activity.

Rafting: A surface float with a straight long axis in the dorsal position and intermittent exposure if the foresection at the surface; the rostrum is rarely visible but occasional backward thrusts of the head appear to keep the blowhole clear of the water. The animal may raft deeply at the interface and expose just the dorsal fin or remain stationary just below the surface without exposing any body parts.

Rocking: Alternate exposure and submergence of the foresection and caudal section by the stationary animal at the interface in the dorsal position. The sections appear to pivot off the midsection and the head may angle down from the neck.

Roll: An accentuated sideways rotation along the long axis by an animal in a dorsal position. The movement is usually continuous from dorsal to lateral with the dorsal fin parallel to the water surface. Rotation is often to one side only.

Surfaces and submergences

Arched dive: A single, abrupt lunge over the surface generally followed by a clean reentry in a dorsal position with a pronounced concave arch. 

Darting surface: A sudden upward and outward thrust of the foresection over the water by a small animal surfacing in the dorsal position. The head bends at the neck and becomes briefly parallel to the surface or the axis remains straight. The caudal section may swing slightly up and back.

Drop foresection submergence: Steep descent from the surface to underwater achieved by a bend at the midsection, which sharply lowers the foresection. The dorsal fin is elevated as the tailstock moves upward and becomes parallel to the surface as the animal makes forward progress.

Fin/tail submergence: Exposure of the dorsal fin and tailstock at the interface before moving underwater. The animal exposes just the fin and tailstock. The foresection is not visible, the blowhole is never exposed and the tailstock often shows a pronounced concave arching.

Flat foresection surfacing: Exposure of the foresection and dorsal fin at the surface in the dorsal position and straight axis. The animal moves continuously from underwater to the interface and momentarily straightens the arch of the foresection before submergence.

Forward progress submergence: Movement from the surface or interface to underwater in a continuous forward arc in the dorsal position. 

Lateral dive: Submergence in a lateral position and concave arch. The animal may rotate sideways from a dorsal position to either side along the long axis.

Leveling off surface: Elevation of the caudal section from the concave arch to a position parallel to the surface. The foresection is exposed at the interface at a slightly oblique angle and remains fixed; elevation generally occurs during a slight pause in forward progress.

Parallel surfacing: Vertical ascent through the water column to the surface in the dorsal position that exposes the ribsection and dorsal fin simultaneously.

Paused surface: A brief halt in forward progress during exposure of the blowhole at the surface before submerging. Paused breaths generally occur at slower swim speeds.

Pivot dive: Sudden near-vertical, head-up emergence of the foresection to the midsection followed by a rapid forward bend, leading to a quick and steep submergence. The rostrum points down sharply and the bend of the neck is pronounced.

Sinking submergence: Vertical descent through the water column from the surface or interface without making forward progress.

Slow surface/abrupt dive: A quiet ascent to the surface followed by an accelerated submergence. The animal slowly becomes parallel to the surface in the dorsal position but moves quickly underwater by lowering the foresection. The tailstock is severely curved during submergence.

Steep dive: Headfirst movement from the surface to underwater which exposes the tailstock. The foresection is dropped smoothly or abruptly by a bend at the midsection in the dorsal position. The tailstock may be arched or straight; the end of the tailstock may arch slightly without exposing the flukes.

Swims

Bowriding: Swimming or forward movement alongside a boat while positioned off the bow between the surface and about a meter underwater. 

Whale riding: Paced forward progress in the dorsal position while flanked off the head of a gray whale that is swimming at the interface with shallow undulations.

Corkscrew swim: Repetitive rotations along the long axis during moderate to rapid forward progress. The long axis is usually parallel to the water surface. This behavior occurs in an individual or by a pair swimming belly-to-belly at the interface or underwater.

Glide: Brief forward progress in the dorsal position without the tailstock movements usually associated with swimming. The body appears to be fully extended along the long axis.

Half-circle turn: A rapid and tight 180 degree reorientation in the dorsal position during forward progress.

Head-up swim: Brief and repetitive exposure of the head during forward progress by an animal in the dorsal position.

Inverted swim: Forward progress with the belly upward.

Lateral swim: Forward progress in a 90 degree rotation from the dorsal position, orienting one pectoral fin upward and the other downward. The upper pectoral fin is often exposed at the surface.

Porpoising: Repetitive performance of abrupt lunges over the water surface between shallow submergences during rapid forward progress in the dorsal position. The flukes bend down and generally retain contact with the water. The rhythm of the behavior varies and reentry is generally clean. Several animals may porpoise simultaneously.

Skimming: A single lunge of rapid forward progress at the interface that produces a 'rooster tail' wake spraying off either side if the dorsum. 

Subsurface swim: Animal makes forward progress in any position while underwater.

Surface finning: The dorsal fin is continuously visible and the only exposed body part as the animal makes forward progress at the interface at any speed. 

Surfing: Planing toward shore at the face of a well-formed wave or tunneling along the top of a crest. The animal progresses obliquely or parallel to the direction of the wave in the dorsal or slightly lateral position; the dorsal fin may be partially exposed. The animal is completely submerged and parallel to the shore along the upper length of the crest. Several animals may surf in bouts.

Swell-riding: Planing toward shore on offshore swells in the dorsal position. A stationary animal faces land until a swell passes and then moves forward with it, exposing the dorsal fin and tailstock.

Undulating swim: Rhythmic forward progress at slow to moderate speeds between underwater and the surface in the dorsal position. 

Veering turn: A sudden change in direction to either side from the original course of forward progress by a submerged animal in the dorsal position without a loss of speed.

Ventral/ventral swim: Brief or prolonged contact of the ventral surfaces of two animals during forward progress. One animal is in the dorsal position and the other is in the inverted position. The pectoral fins of the dorsal animal may be held along the sides of the inverted animal.

Tailstock/Fluke movements

Braking: A sudden downward tuck of the tailstock that orients the flukes obliquely or perpendicular to the ling axis. This behavior often precedes a slowing or stopping as the flukes angle down from the tailstock or the tailstock itself curves down.

Cartwheeling: A sweeping arc formed by the caudal section as it is swung up and forward from the dorsal position over the head. The caudal section appears abruptly and moves rapidly through the air; the foresection is not exposed. The behavior is often repeated and is usually seen during sexual activity.

Erection: An erect penis.

Fluke curl: An upward orientation of the fluke tips, forming a right angle to the cross-plane at submergence. The dorsal fin and the tips of flukes are the last to disappear as the animal submerges.

Fluke shiver: Alternating up-and-down movement of the flukes of an exposed caudal section. One fluke moves up as the other fluke moved down; rapid reversal of this action gives the effect of shivering.

Fluke up: Exposure of one fluke at the surface by a moving or stationary animal. The fluke is usually angled and may flex briefly, often with splashing.

Twisted tail dive: During submergence, the flukes are shifted from the plane of the body and exposed. The foresection appears to remain in the dorsal position while the tailstock twists along the axis and the caudal section may be fully exposed momentarily.

Fluke wave: The animal is in a head-down position with tailstock exposed at the surface at an oblique angle. Flukes and tailstock are swung slowly or rapidly up and down or sideways.

Fluke wipe: The ventral side of the flukes is drawn along some portion of the body of another animal. The flukes are often fully exposed at the surface while the tailstock is barely evident.

Footprints: Round patches of smooth water formed at the surface by tailbeats of a submerged dolphin making forward progress.

Peduncle snap: A swift and powerful downstroke of the tailstock that appears to assist in or cause sudden acceleration. The flukes may briefly flex upward prior to the downswing.

Sideswipe: Sideways cocking and forceful release of the tailstock in the dorsal position. The tailstock curves into an convex arch and twists the flukes upward. This powerful swing is often directed at another animal.

Silent tail snap: The tailstock is raised above the surface and lowered with a decelerated downswing, entering the water cleanly and quietly.

Tailout: Exposure of the caudal section at the surface in a head-down position. The straight tailstock is elevated by a modulated upward movement and the flukes may be flipped up or move up-and-down briefly during exposure.