BIOL202 - Lecture 7 - Revised Overhead

BIOL202 - Lecture 7 - Revised Overhead - LECTURE 7: TROPHIC...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
LECTURE 7: TROPHIC INTERACTIONS II: EFFECT ON PREY POPULATIONS Key question : Do predators usually limit prey abundance, i.e., hold numbers of prey down below environmental carrying capacity? Prior to 1946: Widely assumed that since predators remove prey from environment predators must reduce prey to < K In other words: the more predators, the fewer prey (and visa versa ) Graphical representation of the conventional wisdom: K ------------------------------------------------------------------------------------ w/out predators PREY N w/ predators TIME -----------> 1946: Paul Errington’s proposes Doomed Surplus hypothesis. Says: In many cases: reproductive rate of prey >> repro. rate of predator o As prey population increases, predator population also increases (more food for predators increased survival/reproduction) o However, because of different rates of reproduction , predator numbers do not increase as fast as prey numbers do
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
As such, predators may slow growth of prey pop but will not stop
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 3

BIOL202 - Lecture 7 - Revised Overhead - LECTURE 7: TROPHIC...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online