Flashcards in Pinnipedes Deck (25)
Give the phylogenetic position of the pinnipeds.
In the order Carnivora
Closely related to Mustelids and Ursidae
Give the 3 families contained within the pinnipedes
Otariidae- Eared seals
Phocidae- True seals
Give the use of a walruses tusks and on which sex they are found
Used to battle between males
Protection from predation
Haul themselves onto ice
How is the Odobenidae adapted for feeding ?
Walrus skull is specialised fro feeding on clams and other benthic invertebrates
Give the 2 main groups of eared seal.
Fur seals and Sea lions
Which flippers of the eared seals have a key role in propulsion in water ?
Large fore flippers
(hind only for steering
Why are eared seals more agile than True seals on land ?
Can support weight on foreflippers
Hind flippers turn inwards to enable walking
Which flippers of the eared seals have a key role in terrestrial locomotion ?
Both fore and hind flippers
On which family is a pinna found ?
The Otariidae, Eared seals
Where is the muscle mass found in the family Otariidae ?
Eared seals, At the front of the body
Which flippers do true seals use for swimming ?
Where is the muscle mass found in the family Phocidae
True seals, the rear of the body
Give the distinguishing deatures of the Grey seal.
Parrallel shaped nostrils
Give the defining features of the Common Seal
V shaped nostrils
Give some sensory adaptions of seals
Good vision on land and sea
Higher vocal repertoire
Can hear higher frequencies
Click vocalisations- Echolocation ?
What is delayed implantation ?
A fertilised egg will remain as a blastocyst till its ready to attach to the uterine wall.
Give a collective group within the pinnipeds that exhibit delayed implantation.
What is the advantage to a seal of delayed implantation ?
Condenses breeding season on land (most vulnerable)
Enables birth of pup when environmental conditions ideal
Elephant seals defend matin beaches, what does this enable ?
Alpha male can exhibit Polygyny
up to 100 females a season
Describe the morphology of elephant seals.
3 times the mass of the female
How do male elephant seals establish territory ?
Participating in Bloody fights for dominant position on
How many pups will elephant seal females produce in a 12y lifetime
What happens to subdominant male elephant seals ?
Hang around the edges of the mating beaches and intercept females as they return to the sea.
Male elephant seals (bulls) are very aggressive, give examples of this ?
Will attempt to mate with pregnant females