Expert: Walter Hintz - 8/24/2005

Question
Hi! My name is Deann and Im just starting 8th grade and have some difficult problems that I hope you can help me with, all you have to do is answer the questions in complete sentneces.

1. Ostriches cannot fly. Would you expect them to have more down feathers or more contour feathers. Why?

2. Flying foxes, the largest bats, have a wingspan of about 5 feet. The albatross one of the largest flying birds, has a wingspan of 11.5 feet. Why do you think flying birds can be so much larger than flying birds?

3. Mammals and birds tend to eat much more, realtively, than other veretebrates. Why?

4. Why are dolphins classified as mammals and not as fish?

5. Which is more likely to care for its young, a mammal or a fish?

6. Cats raised by their mothers hunt small rodents, insects, and other creatures. Cats raised in isolation from other cats usually do not hunt these things. Do you think hunting in cats is learned or instictual? Why?

Answer
Hi Deann
1. Contour feathers are flight feathers and a flightless bird has no use for them so the ostrich has downy feathers.
2. I really do not like this question the way it is worded since it is asking why birds  "can" be larger than mammals.  I would answer it this way.  The albatross flies greater distances and under very different conditions than a bat and large size is more important.
3. Mammals and birds are warm blooded with a greater metabolic rate and require more energy.
4.Dolphins have mammary glands and nurse their young and also have hair.
5.The young of a mammal is helpless at birth and requires greater care than a fish.
6. The fact that cats raised in isolation do not hunt shows that hunting is learned behavior.