Dolpin (15) Flashcards
(30 cards)
How does countershading work for aquatic animals?
The darker dorsal side blends in with deeper waters when viewed from above, while the underside blends well with the ocean surface when viewed from below.
What is the significance of the streamlined bodies of bottlenose dolphins?
It significantly reduces drag as they swim.
What muscle powers the swimming movements of bottlenose dolphins?
The peduncle.
Where is the peduncle located on a cetacean’s body?
Between the dorsal fin and the tail.
The darker dorsal side of dolphins helps them blend in with _______.
Deeper, darker waters.
What technique involves dolphins guiding prey onto muddy shorelines?
Intentional beaching - this technique helps dolphins capture prey by bringing them closer to the shore.
- What is ‘fish whacking’ in dolphin behavior?
- What does it result in?
- Dolphins smack fish into the air with their flukes (tail fins).
- This technique often results in the fish landing in the mouths of their podmates.
What does dolphin ‘kerplunking’ involve?
Creating a ring of bubbles around a school of fish - dolphins splash and drive their flukes/tail fins through the water surface to create this effect.
- What is dolphin ‘mud-ring feeding’?
- What is it similar to?
- Suspension of mud into the water column to startle and corral fish
- This technique is similar to kerplunking but uses mud instead of bubbles
What is site fidelity in dolphins?
High site fidelity refers to a limited home-range in certain dolphin populations (though note that some populations are migratory).
What are the two groups of bottlenose dolphins separated into?
Ecotypes (coastal and pelagic).
True or false: there are differences in physical characteristics between coastal and pelagic dolphin eoctypes.
True!
What is the second species of Tursiops found in the Indian Ocean?
Indo-Pacific bottlenose dolphins (Tursiops aduncus) - this species is distinct from the common bottlenose dolphin.
What is the typical color of a newborn bottlenose dolphin calf?
Dark in color with light stripes called fetal folds
- At what age do female bottlenose dolphins generally begin to reproduce successfully?
- What about males?
- 7 – 12 years of age
- Males tend to mature even later than females.
- What is the average inter birth interval for bottlenose dolphins?
- Why is it so high?
- About 4 – 5 years
- This interval is due to the high investment in maternal care.
What is one reproductive issue caused by marine pollution?
Sterility
List two wibbly-wobbly health issues related to marine pollution.
- Birth defects
- Skeletal abnormalities
What concerning thing about cetaceans is linked to noise pollution?
Mass strandings of cetaceans may be linked to noise pollution.
What recent technology is suggested to be linked to cetacean mass strandings?
Naval ‘mid-frequency’ sonar.
What physiological effect was observed in dolphins exposed to mid-frequency sonar?
Temporary hearing loss (remember that dolphins are terrified when they can’t hear anything).
Temporary hearing loss in dolphins is induced only by repeated exposures to __________________ (Don’t forget the decibels!).
Intense sonar pings at around 214 decibels.
What longstanding paradox exists regarding aquatic mammals (TGTs)?
They appear to tolerate and suffer no ill effects from tissue gas tensions that would injure terrestrial animals (AKA the bends).
What type of dolphin vocalisation has received very little academic attention?
Non-signature whistles that are shared by lots of dolphins.
