22- Disease and Conservation

Question 1

what is a parasite

Answer 1

= an organism that lives and draws resources from a host, to the detriment of the most

• microparasites = viruses, bacteria, protzoa, fungi
• macroparasites = worms, anthropods

Question 2

what is a disease

Answer 2

= pathology of an infection (how it is exhibited)

Question 3

methods of disease transmission

Answer 3

1. close contact
   - can be sexual (STDs, HIV) or non sexual (grooming)
2. environmental
3. vector-borne
4. intermediate host

Question 4

what are zoonotic diseases

Answer 4

= diseases transmitted from animals to humans

Question 5

what are reverse zoonotic diseases

Answer 5

= diseases transmitted from humans to animals

- ex scabies in gorillas

Question 6

characteristics of emerging infectious diseases

Answer 6

• recently increased in incidence
• recently increased in geographic range
• recently moved into new host populations
• recently been discovered
• are caused by newly-evolved pathogens

Question 7

zoonotic disease: malaria

Answer 7

• 300 to 500 million clinical cases every year –> 0.7 to 2.7 million deaths
• found mostly in the tropics
• P. malaria is from chimpanzees originally
  (gone from humans back to primates)
• P. vivax is derived from a monkey malaria strain
• P. knowlesi is a new malari in humans and is from macaques

Question 8

zoonotic disease: ebola

Answer 8

• maybe caused by eating bats/ bat feces on fruit/ bushmeat trade
• ebola is also hitting wildlife populations
• taking longer between exposure and exhibiting symptoms –> more likely to spread to other countries

Question 9

what is carrying capacity

Answer 9

= the number of individuals of a species that can be sustained indefinitely by resources in a given area

Question 10

what is density dependent

Answer 10

= when primate density increases, competition for resources, predation, and/or disease can increase in intensity, which has a ‘self-adjusting’ effect on population size
- ex disease will have a greater effect in limiting the growth of a large population, since overcrowding facilitates its spread

Question 11

changes in nutritional status and parasitism associated with changes in host population size

Answer 11

• increased deforestation = decreased population size
• increased deforestation = increased parasite infection = decreased population size
• increased deforestation = increased cortisol = increased in some parasite indices

Question 12

human medical literature: how spread of diseases are affected by climate

Answer 12

1. meningitis epidemics erupt during the dry season
2. heavy rains are associated with outbreaks of waterborne diseases
3. malaria increases with increased rain and temperature

Question 13

what are 2 behavioural counterstrategies in animals to combat diseases

Answer 13

1. Grooming:
   - can groom off the parasites
   - prosomians: genital grooming after mating
2. Medicinal plants
   - primates and other animals treat themselves for diseases
   - kills parasites
   - alleviates pain