Module 1 - Lecture 8

Introduction to Conservation Medicine

• Lecture Five: Wrap-up of Module One.

• Focus on stress and immunosuppression in wildlife.

• Discussion on the impact of stressors on health and population dynamics.

Understanding Stress in Wildlife

• Perception of Stress:

  • Stress often underestimated in wildlife management.

  • Wildlife generally considered well-adapted to stress but challenged by non-natural, chronic stressors.

• Types of Stressors:

  • Acute Stressors:

    • Rapid impact, such as pathogen exposure or acute toxic substances.

    • Immediate threat to health, but often manageable.

  • Chronic Stressors:

    • Long-term exposure leading to immune system suppression.

    • Cumulative effects make assessment more complex.

Importance of Fitness and Health Status

• Fitness in Ecology vs. Conservation Medicine:

  • Ecology focuses on the fitness and survival of populations, often neglecting health status if it doesn't affect reproduction.

  • Conservation medicine emphasizes overall health, including behavior, genetics, and immunological status.

• Impact of Stress on Health and Fitness:

  • Reduced reproductive success can lead to population decline or extinction.

  • Chronic stress disrupts physiological balance, leading to immunosuppression.

Effects of Chronic Stress

• Immunocompromise:

  • Chronic stress leads to a weakened immune system, making individuals more susceptible to diseases.

  • Multifactorial etiology complicates understanding of stress impacts.

• Identifying Factors Affecting Health:

  • Consider environment, genetics, and stress factors affecting individual health and susceptibility to pathogens.

Categories of Stressors Affecting Wildlife Health

• Abiotic Factors:

  • Non-living elements such as temperature, rainfall, etc., that can stress populations.

• Interspecific Factors:

  • Interactions between different species (competition, predation).

• Intraspecific Factors:

  • Social dynamics within a species affecting stress levels (e.g., social hierarchy).

Evolutionary Perspective on Stress

• Evolutionary adaptation allows acute stress responses, but chronic stress disrupts long-term health and fitness.

• Acute stress is generally manageable if the stressor is temporary.

Measuring Stress in Wildlife

• Non-invasive Techniques Preferred:

  • Stress hormones (glucocorticoids) measured in feces, urine, or hair.

  • Reduces the stress response from capturing animals.

• Stress Indicators:

  • Patterns in cortisol levels can indicate stress associated with lactation, social dynamics, and environmental changes.

Anthropogenic Stressors and Their Impacts

• Effects of Human Activities:

  • Habitat destruction, pollution, climate change impact wildlife stress.

  • Examples include nesting sea turtles affected by light pollution or mammals impacted by urban development.

• Tourism Disturbances:

  • Unregulated tourism leads to stress and behavioral changes in wildlife.

• Hunting and Overexploitation:

  • Different impacts from subsistence, recreational hunting, and poaching on population health.

Conclusion and Future Directions

• Impact of Chronic Stressors:

  • Chronic stressors can lead to immunocompromise and increased disease susceptibility.

• Management Recommendations:

  • Careful design of wildlife management practices to minimize stress.

  • Importance of monitoring health and stress levels in wildlife populations.

• Next Module Overview:

  • Transition into Module Two focusing on infectious diseases and their relation to conservation medicine.