Primate Parasitic Infection and Habitat Change Notes

Malnutrition in Primates

  • Common forms:

    • Protein energy malnutrition (especially in humans)

    • Micronutrient deficiencies (less common in non-human)

  • Non-human primates get more micronutrients from their natural diets (fruits, vegetables, leaves, bark, etc.) compared to cultivated human foods.

  • Negative impacts of malnutrition:

    • Starvation

    • Reduced reproductive output

    • Increased mortality

    • Decreased quality of life and mobility

Habitat and Climate Change & Parasitic Infection

  • Emergence of parasitic infections is a result of changes in the ecology of the host (primates) and/or the parasite.

Lecture Goals:

  • Explain species associations between primates and their environment.

  • Understand where parasitism fits into the ecosystem model.

  • Define ecto- and endoparasites and explain transmission.

  • Give examples of how primates deal with parasites.

  • Explain how habitat change impacts parasitic infection.

    • Understand pioneer species and parasitic risk.

  • Case study: Howler monkey parasitic infections after habitat change (Alison Behe).

Ecosystem Interactions

  • Ecosystems involve complex interactions between species.

  • Diagram example: African animals interacting (snakes, chimps, birds, livestock, humans, etc.)

Species Associations

  • Describing relationships between animals using a "+" (benefit) and "-" (loss) system.

Mutualism (+/+)

  • Both species benefit.

Commensalism (+/0)

  • One species benefits, the other is unaffected.

Parasitism (+/-)

  • One species (parasite) benefits, the other (host) is harmed.

Primatology Examples

Mutualism

  • Primates disperse seeds by eating fruit, seeds pass through their gut, and are deposited elsewhere.

  • Seeds germinating after passing through primate guts have:

    • Higher germination rates

    • Shorter germination times

    • Faster initial growth

Commensalism

  • Red colobus monkeys associate with Diana monkeys.

  • Diana monkeys give alarm calls for chimpanzee predators.

  • Red colobus benefit by avoiding vigilance, Diana monkeys are unaffected.

Parasitism

  • Parasites usually have negative effects on primates.

  • Ectoparasites: Live outside the body (ticks, lice, mites).

  • Endoparasites: Live inside the body.

Ectoparasites and Group Living

  • Parasitism is a cost of group living.

  • Higher infection rates in primates that live in larger groups and have more social partners.

  • Dealing with ectoparasites:

    • Grooming: Serves social purposes and parasite removal; location indicates whether social or for parasite removal.

    • Fur rubbing: Applying substances (millipedes, plant secretions) as anti-parasitics.

Assessing Parasites in Primates

  • Look for signs: hair loss, ticks, etc.

  • Indirect assessment: Increased grooming rates.

  • Trapping animals and counting ectoparasites (requires ethics clearance).

Consequences of High Ectoparasite Load

  • Consuming resources, taking energy from the primate.

  • Can trigger ectoparasite defense system, leading to excessive scratching, skin picking, trichotillomania, or delusional parasitosis.

  • Vectors transmit diseases (e.g., ticks passing Kyasanur Forest disease between monkeys).

  • Mosquitoes pass along malaria.

  • > 3000 monkeys died in India from Kyasanur Forest Disease over a 60-year period.

Endoparasites

  • Live inside the body, often in the intestines, but can be elsewhere (e.g., heartworm).

  • Cost of group living.

    • Transmitted directly or indirectly.

Direct Transmission

  • Host to host (e.g., fecal-oral route).

  • Monkeys defecating in trees, feces contaminating leaves eaten by other monkeys.

  • Trichuris eggs develop in soil, monkeys eat soil for micronutrients.

  • Sociality influence: More individuals in an area, higher risk of transmission.

  • Home range size affects reinfection likelihood.

  • Weather affects parasite survival.

  • Chapman et al. found increased parasite load in red colobus and black and white colobus when population density increased due to forest fragmentation in Africa.

Indirect Transmission

  • Requires a vector (intermediate host).

  • Infection through diet (e.g., consuming ants).

  • Influenced by diet and weather (helminths thrive in wet, strongyloides in lower temperatures).

Entamoeba Endoparasites

  • E. coli and E. histolytica: common, cause intestinal upset.

  • Found in high rates in captivity; cross-contamination during feeding and cleaning increases spread.

  • More cross-contamination between feeding and cleaning, and watering meant there were higher chances of pests

Managing Endoparasites

  • Zoopharmacognosy: Animal self-medication.

    • Chimpanzees eat specific plants (e.g., Aspilia leaves) to disrupt worm life cycles by swallowing them whole, unchewed.

    • McLenan et al. propose that perhaps monkeys handle intestinal parasites better than expected, and may not even show signs of disease, but simply be managing it themselves

    • Red-fronted lemurs in Madagascar rub toxic secretions from millipedes on their anogenital region to target parasites emerging from the anus during the wet season.

Habitat Change Affecting Parasitic Infection

  • Primates face conservation challenges:

    • Clearing for agriculture (slash and burn, palm oil plantations) and mining (habitat loss).

    • Road construction (fragments habitats).

    • Logging and resource collection (habitat degradation).

    • Climate change.

  • All lead to increased exposure to people.

Impact

  • Habitat disturbance increases exposure to parasites leading to zoonotic disease transfer.

  • Changes in plant composition increase exposure to parasites.

  • Compromises in food supply lead to dietary stress and reduced immunity, increasing susceptibility to parasites.

  • Orangutans in slash and burn locations leads to more parasites

Zoonotic Disease

  • Reciprocal infection between humans and other animals

  • Zoonotic disease transfer includes: yellow fever, herpes B, tuberculosis, AIDS, Ebola, Salmonella, E. coli, malaria, giardia, cryptosporidium, etc. Some are not species specific

  • Chimpanzees in degraded forests or near human agriculture have higher rates of Giardia and hookworm.

  • Julie Tekrobe found Giardia assemblage B is the same strain between black-and-white colobus and humans in a village in Ghana.

    • Contact with humans due to habitat fragmentation increases zoonotic disease transfer.

  • More fragmentation of forests results in more chances of humans to get in and do what they do

Nutritional Stress

  • Habitat disturbance/fragmentation can make animals more susceptible

  • Chapman et al. propose it is through nutritional stress caused by logging:

    • Parasites directly cause survival and reproduction issues (blood loss, nutritional deficiencies, abortion, death).

    • Indirectly cause issues through reduced bodily condition.

    • Parasites increase the energy requirements and can make traveling and the ability to escape predators more difficult, as well as competing for food

    • Causes immune suppression issues.

    • Chapman found lower cortisol levels in intact forests than in disturbed forests when studying red colobus in Africa.

      • Lowering food availability also causes an indirect population decline because of the secondary parasitic infections.

        • The cycle: forest loss is leading to dietary stress, which is leading to immune suppression issues, increasing more likely that they're going to get parasites, which means they have to eat more, which puts you into more dietary stress.

  • Gillespie et al. found more parasite infection stages in logged forests when comparing the species of two colpos and Guanins

  • With Glennon, there was a significant difference in individual parasite infections
    *The logging had a disproportionate affect on Glennons fruiting food, meaning there would be a decline in Glennons intake in not only the amount of protein, but other mineral and nutrient factors

Alice's Howler Monkey Study

  • Behe (Alison Behe's former supervisor) studied howler monkeys and found that when there was a decline in fruit consumption, there was an energy malnutrition, meaning they were not getting enough calories.

    • The population study was about fruit, and its population density, and cortisol stress

      • The population declining was determined by fruit being a direct correlation to a decline in population, along with people consuming Cortisol

      • This led to physiological stress, which led to decline in fruit consumption, leading to an increase in cortisol and a decrease in the population density.

Howler Monkey Case Study (Hurricane Iris in Belize)

  • Hurricane resulted in defoliation and death of food and fruit trees.

  • Pavelka began a study in Belize on howler monkeys in 1999, and when Hurricane came, Alison went out to do her dissertation and was able to see how the monkeys deal with massive habitat changes

  • She was able to take advantage of the really unique post hurricane research opportunity

Impacts after the Hurricane

  • Population crashed.

  • Studied density, food availability/nutrition, stress (fecal samples), parasitism (fecal samples).

  • Habitat, food resources, population size, reproductive rates, mortality rates, and parasitic infection rates all changed.

Rebound

  • Group size has started to stabilize and improve.

  • Fruit givory (rate of fruit eating) eventual rebelled back up to relatively pre hurricane levels.

Habitat and Dietary Changes

  • Circopa pelletata increased in availability after the hurricane, and the plant made up 3/4 of the entire diet (both the leaf and the stem).

  • The leaves are an excellent food source, which lead to eating more of the umbrella leaf and stem for a colonizing species

Pioneer Species

  • First ones into an area

  • Colonizing the species after they had some form of a gas canopy which logging will bring to an area or environment.

  • The forest then has a food composition which changes the food availability to the howler monkeys.

  • Cecropia species are not limited by light and only live where there are high amounts of sun they can use.

  • Invest in the rapid growth and are not putting energy into defining so hands low fibre.

Parasites

  • Controarchus is the most prevalent parasite.

    • Flatworm, trematode (intestinal flatworms).

    • Indirectly transmitted, requires an intermediate host.

    • Life cycle: flatworm lives in gallbladder of howler monkey eggs come out in feces snail gets infected snail infects an ant ant ends up back in monkeys.

      • the Cergropa had an increasing amount, which will show the red bars when eating the umbrella tree, showing the more likely they are to be infected the more they eat of specific plants

Cecropia and Ants

  • They are an ant loving plant and have a mutualistic relationship with azteca ants. and Cecropia has increasing amounts of something that is high light.

  • Pioneer species, very abundant in disturbed areas.

    • Invest in rapid growth instead of defense.

    • Because there has a lot of ants on it, it is increasing its exposure. Also the monkeys have their leaves. And as Pioneer species, they also commonly used by primates.

  • While we talk about how fragmentation may reduce food availability, it could also increase in. So now there's just more opportunities for what you want to get out of it.

Linking Habitat Disturbance and Parasitism

  • The association between habitat disturbance and an increase in parasitism can be explained by the increased exposure from the ants to the Leaves.

  • Habitat disturbance increases exposure indirectly through the nutritional profile.

Another Way to Look at it

  • Habitat disturbance leads to changed food availability animals eat different things (pioneer species) change to nutritional profile unintentionally consuming ants that are the second vector passing along the parasite.

  • Indirectly link habitat change to parasitism through consider the change in habitat diet and response.

Systems Thinking

  • Holistic way to address complex systems like ecosystems.

  • Considers both biotic (living) and abiotic (non-living) factors (rain, temperature, light, etc.).

  • Systems science is incorporating by and large human influences, but is an encompassing way or method to better influence humans more into this ecosystem rather than making them separate to it.

Takeaways

Humans as animals can be affected with climate change, which will then cause them to act in a way that has them not think properly about the ecosystem they are living and the food that they want to study.