Subject: Re: food chains

Dr. Cathy Schaeff (schaeff@american.edu)
Mon, 06 Oct 1997 10:45:56 +0000

JEMILA FAIRLEY wrote:
> 
> I am in an enviornmental science class and we are currently studying
> ecosystems and food webs.  I would greatly appreciate it if you could
> help me put the following animals in order as to what it eats:


> Thank you for your time and consideration.  I realize that you are a
> busy person, and I'll appreciate any information you can give me.
> 
> Sincerely,
> Jemila Fairley


How about if I give you clues so that you can order the organisms
yourself?

1.

-humans:  what do we hunt?  We are generally at the very top since we
adjust what we can prey upon by inventing tools which make us able to
over come even species which are much larger and stronger!  

2.
 -sperm whale
 -Blue whale
 -Killer whale

Two of the whale species are toothed whales and therefore at the top of
the food web.  The third is a baleen species which eats small items of
prey.


3.

-Adelie peguins
-squid
-leopard seal
-petrel
-fish
-krill
-elephant seal
-emperor penguin
-crabeater seal
-herbivorous zooplankton
-phytoplankton
-carnivorous plankton

Baleen species eat small prey items (since they don't have teeth to help
break the prey into smaller peices).  Which of the above (there are
four) would be small enough for a baleen whale to eat?

4.

-Adelie peguins
-squid
-leopard seal
-petrel
-fish
-krill
-elephant seal
-emperor penguin
-crabeater seal
-herbivorous zooplankton
-phytoplankton
-carnivorous plankton

Which would the two carnivore whale species eat? (Think about where each
of the whale species are found and so what food types would be
available).

5.

Among the prey species, which ones would eat others in the list? (try to
link one prey, food type, to each species)

-Adelie peguins
-squid
-leopard seal
-petrel
-fish
-krill
-elephant seal
-emperor penguin
-crabeater seal
-herbivorous zooplankton
-phytoplankton
-carnivorous plankton




6.
-herbivorous zooplankton
-phytoplankton
-carnivorous plankton

These speices are at the bottom relative to other species -- they form a
chain with one producing food, the second eating the first and the third
eating the second!


See how you do with this.  If you get stuck, send back what you think is
the correct order of the species and I'll help again.

Cathy Schaeff
-- 
Dr. Cathy Schaeff
Biology Department 
American University
4400 Mass. Ave. N.W. 
Washington D.C. 20016-8007
(202) 885-2175 (phone)
(202) 885-2182 (fax)
schaeff@american.edu (email)