Conservation Biology Midterm 2
2026-2027
Expert-Verified Questions and Answers
(With A+ Grades Guarantee)
, Deterministic models perform the same way for a given set of initial conditions.
Stochastic models can give a range of outcomes from the same initial conditions
1) Best of the stochastic predictions (population grew a LOT)
2) Deterministic prediction
3) Worst of the stochastic predictions (population declines)
Environmental stochasticity increases extinction risk
bad years are bad for the average growth rate
strings of bad years can lead to extinction
Catastrophes increases extinction risk but are not predictable from historical data
Demographic stochasticity increases extinction risk and is strongest at small population sizes.
Population Viability Analysis Methods for predicting population trends and risk of
(PVA) extinction
What are the methods for predicting population trends and include:
risk of • Estimates of population size
extinction • Predictions about trend in population
• Predictions about variability over time
Are mobile species harder to protect Very mobile species can be particularly hard to protect
Stages of progression on Logistic Growth Model 1) Birth Exceed Deaths
2) Resources Abundant
3) Fastest growth of population
4) Resources becoming limited
5) Resources start becoming limited
6) Births = Deaths
Typical relationship between per-capita population growth Negative Linear
and population size Lower population Higher per-capita population growth
Higher population Lower per-capita population growth
Who was Allee? Studied animal behavior, was interested in the benefits of living in groups
(flip side is costs of living alone, or at very low densities).
What is Allee effect An Allee effect occurs when per-capita population
growth rate is negative at low population densities
Example of an Allee effect Has broadcast spawning (just put eggs and sperm out into
the water). But if the animals are at low density, the eggs
and sperm almost never find each other and there is very
little successful reproduction.
When Allee effect is present, populations crash if below a True
critical level
2026-2027
Expert-Verified Questions and Answers
(With A+ Grades Guarantee)
, Deterministic models perform the same way for a given set of initial conditions.
Stochastic models can give a range of outcomes from the same initial conditions
1) Best of the stochastic predictions (population grew a LOT)
2) Deterministic prediction
3) Worst of the stochastic predictions (population declines)
Environmental stochasticity increases extinction risk
bad years are bad for the average growth rate
strings of bad years can lead to extinction
Catastrophes increases extinction risk but are not predictable from historical data
Demographic stochasticity increases extinction risk and is strongest at small population sizes.
Population Viability Analysis Methods for predicting population trends and risk of
(PVA) extinction
What are the methods for predicting population trends and include:
risk of • Estimates of population size
extinction • Predictions about trend in population
• Predictions about variability over time
Are mobile species harder to protect Very mobile species can be particularly hard to protect
Stages of progression on Logistic Growth Model 1) Birth Exceed Deaths
2) Resources Abundant
3) Fastest growth of population
4) Resources becoming limited
5) Resources start becoming limited
6) Births = Deaths
Typical relationship between per-capita population growth Negative Linear
and population size Lower population Higher per-capita population growth
Higher population Lower per-capita population growth
Who was Allee? Studied animal behavior, was interested in the benefits of living in groups
(flip side is costs of living alone, or at very low densities).
What is Allee effect An Allee effect occurs when per-capita population
growth rate is negative at low population densities
Example of an Allee effect Has broadcast spawning (just put eggs and sperm out into
the water). But if the animals are at low density, the eggs
and sperm almost never find each other and there is very
little successful reproduction.
When Allee effect is present, populations crash if below a True
critical level
