Holling’s functional response curve: The total number P of prey taken by a predator depends on the availability of prey. C. S. Holling proposed a function of the form P = cn/(1 + dn) to model the...

Holling’s functional response curve: The total number P of prey taken by a predator depends on the availability of prey. C. S. Holling proposed a function of the form P = cn/(1 + dn) to model the number of prey taken in certain situations.25 Here n is the density of prey available, and c and d are constants that depend on the organisms involved as well as on other environmental features. Holling took data gathered earlier by T. Burnett on the number of sawfly cocoons found by a small wasp parasite at given host density. In one such experiment conducted, Holling found the relationship

where P is the number of cocoons parasitized and n is the density of cocoons available (measured as number per square inch).

a. Draw a graph of P versus n. Include values of n up to 2 cocoons per square inch.

b. What density of cocoons will ensure that the wasp will find and parasitize 6 of them?

c. There is a limit to the number of cocoons that the wasp is able to parasitize no matter how readily available the prey may be. What is this upper limit?