Biodiversity, Predators, & the Dilution Effect

Question 1

Reservoir competence

Answer 1

The mean percentage of vectors infected by an individual host

Question 2

How does host diversity affect transmission dilution effect?

Answer 2

Lower host diversity in a community will result in high reservoir competence, and high host diversity will result in lower reservoir competence as some bites will be wasted

Question 3

4 requirements for the transmission dilution effect

Answer 3

1. Vector species is generalist feeder
2. Pathogen is acquired by vector from hosts (not transmitted vertically)
3. Reservoir competence varies among host species
4. Most competent reservoir host tends to be abundant in low diversity communities

Question 4

Susceptible Host Regulation Dilution Effect

Answer 4

Regulating the prevalence of the host species in a community can effectively reduce disease prevalence (either by competitors or predation)

Question 5

Encounter Reduction Dilution Effects

Answer 5

Reduce local density of host species, which should avoid transmission of vectors between them

Question 6

Requirements for predators to be good for your health

Answer 6

1. Disease risk is positively corelated with reservoir host abundance
2. Predators either preferentially prey upon infected hosts or show no relationship with host infection status

Question 7

How might predators be bad for your health

Answer 7

• If the predator avoid infected prey
• If the pathogen becomes the primary regulator of prey/reservoir host abundance

Question 8

Complementarity

Answer 8

The extent of overlap between organisms within a functional group

Question 9

Communities with ____ complementarity should be ____ resistant / resilient to ecosystem disturbance

Answer 9

High; more

Question 10

Trophic skew

Answer 10

Large animals with large home range sizes and low densities are first to go extinct