Unit 3.3 - Survivorship Curve

Question 1

Survivorship curve

Answer 1

• line that shows survival rate of a cohort (group of same-aged individuals) in a pop. from birth to death
• Faster drop in line = quicker die-off of individuals
• Slower drop in line = longer avg. lifespan

Question 2

Type I

Answer 2

• mostly K-selected species
• High survivorship early in life due to high parental care
• High survivorship in mid life due to large size & defensive behavior
• Rapid decrease in survivorship in late life as old age sets in
  - Ex: most mammals

Question 3

Type II

Answer 3

• In between K and r
• Steadily decreasing survivorship throughout life
• ex: squirrels because they randomly die throughout life

Question 4

Type III

Answer 4

• mostly r-selected species
• High mortality (low survivorship) early in life due to little to no parental care
• Few make it to midlife; slow, steady decline in survivorship in mid life
• Even fewer make it to adulthood; slow decline in survivorship in old age
  - Ex: insects, fish, plants