Chapter 14 Regulation of POPULATION SIZE Chapter Opener Chapter 14 Regulation of POPULATION SIZE What stops population growth? What determines average abundance?

4 POPULATIONS OF SAME SPECIES Figure 14-1 4 POPULATIONS OF SAME SPECIES Good habitat

a) Density dependent rate: As a Figure 14-2 a) Density dependent rate: As a population density rises, birth decreases and death increases B,C) Density independent rate: As a population density rises, rate does not change

Population regulation process Figure 14-4 Population regulation process Extrinsic Intrinsic

Figure 14-5 See page 435

Metapopulation: Dot: animal or plant Arrow: dispersal Circle: habitats Figure 14-6 Dot: animal or plant Arrow: dispersal Circle: habitats Metapopulation: Local population in patch that are linked together by dispersal

Figure 14-7 3 years Small patches supported small population and had a greater chance if going Extinct.

Allee Effect: What is the difference between Figure 14-9 Allee Effect: What is the difference between standard population model and population with allee effect? Zero growth Allee (1931) pointed out that undercrowding could be harmful to social species as overcrowding

Example: Huttons’s shearwater (New Zealand)