Population dynamics

Question 1

what are ways of counting and locating individuals?

Answer 1

• full count: census
• partial count: survey
• direct counts
• indirect counts

Question 2

what are examples of indirect counts?

Answer 2

eDNA, tracks/scat counts, camera traps, bat recorders, satellite/remote sensed data

Question 3

what are three types of survey design?

Answer 3

• points
• transects
• quadrats

Question 4

point survey design

Answer 4

go to one place and count number of species

Question 5

transect survey design

Answer 5

• uniform
• random
• stratified

Question 6

quadrat survey design

Answer 6

go to one location and measure but within a physical square

Question 7

what is mark-recapture survey used to test for?

Answer 7

• abundance
• life history: survival and reproduction rates
• movement: dispersal

Question 8

what are issues with sampling?

Answer 8

• Temporal heterogeneity: over time, the number may be different
• Spatial heterogeneity: numbers may not be the same in different areas
• Sampling variability – observer error
• Detectability: how well can you see something that’s actually there

Question 9

what affects detectability?

Answer 9

• Characteristics of the organism:
  
  • Size
  • Coloration
  • Behaviour
    -Characteristics of the environment:
  • Vegetation cover
  • Terrain
  • Weather conditions
• Characteristics of the observer:
  
  • Experience
  • Attention

Question 10

How do you track changes in abundace?

Answer 10

population models

Question 11

population models

Answer 11

mathematical and statistical equations/tools aimed to describe how the number of individuals changes over time.

Question 12

what are the three types of population models?

Answer 12

• unstructured models
• age or class structured models
• individual based models

Question 13

what limits population growth?

Answer 13

• Abiotic conditions:
  
  • Seasonal, predictable (K)
  • Stochastic events
• Density dependence:
  
  • Negative (K)
  • Allee effects

Question 14

what data is needed for age of class individual structured model?

Answer 14

• Abundance for each stage at least at one point in time
• Vital rates: growth, survival and fecundity for each stage
  
  • Cohort approach
  • Static approach

Question 15

stochasticity

Answer 15

• Observation error
• Process error
  
  • Environmental stochasticity
    
    • Unexpected weather
  • Demographic stochasticity
    
    • Birth and mortality rates, sex ratios

Question 16

what increases extinction risk?

Answer 16

• small population size
• fluctuations
• connectivity