Mammal Adaptations

Question 1

What are the TWO main groups of mammals adapted to swimming? (How many times did they evolve?)

Answer 1

> Semi-aquatic mammals (evolved many times)

> Fully aquatic Marine mammals (evolved three times)

Question 2

(Ex) What are some semi-aquatic mammals?

Answer 2

Platypus (Infraclass Monotremata)

Water Opossum (Infraclass Metatheria [Marsupialia] )

Beavers

Hippopotomi

Question 3

(Ex) What are the THREE marine mammal taxa?

Answer 3

Pinnipeds (seals/sealions)

Sirenians (manatees/dugongs)

Cetaceans (whales/dolphins)

Question 4

What wing & body adaptations do Hovering Bats have?

Answer 4

Good Manoeuvrability:

• Vertical Body posture
• Horizontal wing movements (F/B)

Beating wing F/B for thrust & lift, and flexing foward to move wing backward (for no contribution; hold steady).

Low WL and AR, and Camber is High.

Question 5

What wing & body adaptations do Fast-Flying Bats have?

Answer 5

Good Speed:

• Horizontal Body posture
• Vertical wing movements (U/D)

Beating wing Down for thrust & lift.
Upward movement generates lift @ high speeds.

High WL and AR, and Camber is Low.

Question 6

(Ex) Variation in Mammal Milk Production: Give THREE Examples!

Answer 6

Hooded Seal:

• Milk 60% Fat
• Lactate for 4 days only

Black Rhino:

• Milk 0.5% Fat
• Lactate for 2 years

Tamar Wallabies
- Different kinds of milk for different age offspring from different nipples!

Question 7

What FOUR things is the Degree of Precociality based on?

Answer 7

• Thermoregulation (hair)
• Sensory (eyes open)
• Locomotion (move independently)
• Nutrition (feed on solids)

Question 8

What percentage of mammal species studied by Derrikson (1992) were fully altricial?

Answer 8

43% were FULLY altricial