Natural History & Anatomy

Sensory system impact on behaviors and

training

NATURAL HISTORY & NATURAL HISTORY & ANATOMYANATOMYDISCRIMINATING DOLPHINS V. DISCRIMINATING DOLPHINS V.

PORPOISESPORPOISES

NATURAL HISTORY & NATURAL HISTORY & ANATOMYANATOMYDOLPHIN CLASSIFICATIONDOLPHIN CLASSIFICATION

Kingdom.……………………..Animalia

Phylum………………………. Chordata

Class………………………….Mammalia

Order………………………….Cetacea

Suborder ……………………..Odontoceti

Family…………………………Delphinidae

Genus…………………………Tursiops

Species……………………….truncatus

Subspecies…………………..truncatus

Common……………………..Atlantic bottlenose

dolphin

NATURAL HISTORY & NATURAL HISTORY & ANATOMYANATOMYDISTRIBUTIONDISTRIBUTION

• Bottlenose dolphins are the most prolific Bottlenose dolphins are the most prolific dolphins in the worlddolphins in the world

• Found in temperate and tropical watersFound in temperate and tropical waters• Atlantic bottlenose dolphins live in shallow Atlantic bottlenose dolphins live in shallow

coastal waterscoastal waters• Can reach speeds of Can reach speeds of

about 25 mph about 25 mph

NATURAL HISTORY & NATURAL HISTORY & ANATOMYANATOMYBODY SIZEBODY SIZE

• Females tend to be larger than males until Females tend to be larger than males until the age of 6the age of 6

• By 10 years old, females reach full body mass By 10 years old, females reach full body mass whereas males are only at 70% of body masswhereas males are only at 70% of body mass

• Size: 6 ½ - 12 feetSize: 6 ½ - 12 feet• Average weight: 440 lbsAverage weight: 440 lbs

NATURAL HISTORY & NATURAL HISTORY & ANATOMYANATOMYEPIDERMISEPIDERMIS

• Composed of many layers Composed of many layers of flattened epithelial cellsof flattened epithelial cells

• Outer layers contain Outer layers contain keratin, a water-resistant keratin, a water-resistant proteinprotein

• Outer layer may be Outer layer may be replaced every 2 hoursreplaced every 2 hours

• Laminar flow: reduces the Laminar flow: reduces the turbulence next to the skin turbulence next to the skin and allows for more and allows for more efficient swimmingefficient swimming

NATURAL HISTORY & NATURAL HISTORY & ANATOMYANATOMYBODY TEMPERATUREBODY TEMPERATURE

• The water can draw heat away from an The water can draw heat away from an unprotected animal, so cetaceans depend unprotected animal, so cetaceans depend upon a layer of blubber for insulationupon a layer of blubber for insulation

• Body temperature is around 98.7 degreesBody temperature is around 98.7 degrees• With human care they can live out of water With human care they can live out of water

for 36-48 hoursfor 36-48 hours• Can tolerate temperatures down to 52 Can tolerate temperatures down to 52

degrees for 4 hoursdegrees for 4 hours

NATURAL HISTORY & NATURAL HISTORY & ANATOMYANATOMYSKELETAL SYSTEMSKELETAL SYSTEM

• 12-14 vertebral ribs12-14 vertebral ribs• 59-67 vertebrae59-67 vertebrae

NATURAL HISTORY & NATURAL HISTORY & ANATOMYANATOMYBRAINBRAIN

• Delphinidae members have the highest brain Delphinidae members have the highest brain size to body size among cetaceanssize to body size among cetaceans

• Comparing brain weight as a percentage of Comparing brain weight as a percentage of body weightbody weight– Bottlenose dolphin: 0.94%Bottlenose dolphin: 0.94%– Human: 2.1%Human: 2.1%

NATURAL HISTORY & NATURAL HISTORY & ANATOMYANATOMYBRAIN: CORPUS CALLOSUMBRAIN: CORPUS CALLOSUM

• A large bundle of nerve fibers that connects A large bundle of nerve fibers that connects the two cerebral hemispheresthe two cerebral hemispheres

• Hemispheres are important in the Hemispheres are important in the transmission of learned behavior from one transmission of learned behavior from one hemisphere to anotherhemisphere to another

• Compared to humans, in dolphins the two Compared to humans, in dolphins the two hemispheres operate more independently of hemispheres operate more independently of each othereach other– This may be related to dolphins’ sleep patternsThis may be related to dolphins’ sleep patterns

NATURAL HISTORY & NATURAL HISTORY & ANATOMYANATOMYDIVINGDIVING

• Dolphins usually dive according to where Dolphins usually dive according to where they live, but 1,000 feet is the limitthey live, but 1,000 feet is the limit

• Their lungs are about 4 times the size of oursTheir lungs are about 4 times the size of ours• They exchange 80% of their lung capacity They exchange 80% of their lung capacity

with every breathwith every breath• Dolphins can hold their breath for 10 minutesDolphins can hold their breath for 10 minutes

NATURAL HISTORY & NATURAL HISTORY & ANATOMYANATOMYEYES/VISIONEYES/VISION

• Can see well in and out Can see well in and out of the waterof the water

• Dolphins do have rods Dolphins do have rods (black and white) and (black and white) and cones (usually for color cones (usually for color differentiation)differentiation)

• Probably see mostly in Probably see mostly in shades of black and shades of black and white, and they may white, and they may see in shades of green see in shades of green and blueand blue

NATURAL HISTORY & NATURAL HISTORY & ANATOMYANATOMYTEETH/FEEDINGTEETH/FEEDING

• 72-108 cone shaped 72-108 cone shaped teethteeth

• Nondeciduous: only Nondeciduous: only have one set of have one set of teeth their whole teeth their whole liveslives

• Hunt in groupsHunt in groups• Use echolocation to Use echolocation to

find preyfind prey

NATURAL HISTORY & NATURAL HISTORY & ANATOMYANATOMYECHOLOCATIONECHOLOCATION

NATURAL HISTORY & NATURAL HISTORY & ANATOMYANATOMYGOOSEBEAKGOOSEBEAK

• Larynx is modified into the goosebeakLarynx is modified into the goosebeak• No vocal chords present in dolphinsNo vocal chords present in dolphins• The goosebeak separates the breathing The goosebeak separates the breathing

passage from the ingestion passagepassage from the ingestion passage• Allows for simultaneous sound production Allows for simultaneous sound production

and swallowingand swallowing

NATURAL HISTORY & NATURAL HISTORY & ANATOMYANATOMYEARS/HEARINGEARS/HEARING

• Sound travels 4x faster in water than in airSound travels 4x faster in water than in air• In cetaceans, the inner ears are isolated from In cetaceans, the inner ears are isolated from

the skullthe skull– Completed by long Completed by long

auditory canals auditory canals– Ending with an Ending with an

external holeexternal hole

EaEarr

NATURAL HISTORY & NATURAL HISTORY & ANATOMYANATOMYCOMMUNICATIONCOMMUNICATION

• Dolphins communicate through whistles, clicks, Dolphins communicate through whistles, clicks, and body posturesand body postures

• Maximum capacity is 20 different types of whistlesMaximum capacity is 20 different types of whistles• There is a theory that whistles are used to There is a theory that whistles are used to

communicate identity, location, and emotional communicate identity, location, and emotional statestate

• Dolphins will mimic each other’s whistlesDolphins will mimic each other’s whistles• Females tend to have a different signature whistle Females tend to have a different signature whistle

than their mom’s, males tend to have similar onesthan their mom’s, males tend to have similar ones

NATURAL HISTORY & NATURAL HISTORY & ANATOMYANATOMYSOCIALIZATIONSOCIALIZATION

• Dolphins do not mate for lifeDolphins do not mate for life• ““Fission and Fusion Society”Fission and Fusion Society”• MalesMales

– Tend to be in pods only during certain timesTend to be in pods only during certain times– Generally not in pods during times of birthGenerally not in pods during times of birth– More solitaryMore solitary

• FemalesFemales– Generally found in podsGenerally found in pods– Aid in protection and feedingAid in protection and feeding