Extreme Mammals_adapatations_to_human_impacts_Moodle2023

Human Impacts
- Generally negative overall effects of human activities on wildlife.
- Some mammals adapt to the changes, either short-term or long-term.
- Specific examples are essential for understanding adaptations.
- Must take a balanced perspective when examining human impacts and adaptations.

Types of Impacts
- Habitat Fragmentation
- Hunting/Harvesting
- Climate Change
- Pollution

Definitions
- Affects processes in population biology resulting from patchiness in habitats.
- Low fragmentation with high connectivity benefits populations; isolated populations are at risk.
- Long-term effects can magnify challenges faced by wildlife.
Impact Categories
- Affects species differently, generally categorized into:
  - Specialist Species: require specific habitat conditions.
  - Generalist Species: can thrive in various environments.
Vulnerabilities of Carnivores
- Lower population densities and large home ranges make carnivores particularly susceptible to habitat loss.
- Often face persecution from humans due to conflicts.

Consequences
- Introduction of linear features like roads, fences, and powerlines limits movement.
- Increases mortality rates, hunting, poaching, and stress from visual and noise disruptions.
Positive Adaptations
- Some carnivores benefit from these features for travel and hunting.
- Can exploit edge habitats and scavenge on roads more effectively.

Species Overview
- Both are generalist medium-sized carnivores.
Adaptation Traits
- Exhibiting habitat plasticity, allowing adaptation to fragmented environments.
- Movement data indicates faster and more directional travel along roads compared to areas further away.

Changes in Wild Populations
- Harvesting leads to alterations in:
  - Morphological traits
  - Behavioral traits
  - Life history characteristics
- Impedes evolutionary mechanisms and slows population recovery.
Example: African Elephants (Loxodonta africana)
- Harvesting results in size selection impacting age structure, affecting older males disproportionately due to larger tusks.
- Continuous poaching leads to evolutionary changes concerning tusk size.

Vulnerability Factors
- Species face challenges related to:
  - Exposure to new environments
  - Sensitivity to temperature changes
  - Resilience capacities
  - Adaptability to changing climates.
Response Options
- Range redistribution within climate-tolerant limits.
- Adjusting at a local level through genetic composition or phenotypic changes.
- Risk of extinction at both local and global scales.

Shift in Distribution
- Marine mammals reliant on ice face severe challenges with rapid climate shifts.
Resilience Scenarios
- Ice Obligate, Ice Associated, and Seasonally Migrant species show varying levels of resilience to these changes.

Adaptation Strategies
- Expanded geographical ranges may benefit some species due to net losses in sea ice.
- Resilience is assessed through adaptive capabilities of generalist species.

Micro-evolution
- Heritable shifts in allele frequencies may alter morphologies; an example being coat color changes in relation to climate.
Case Study: Springbok (Antidorcas marsupialis)
- Coat color influences thermoregulation and energy efficiency across different temperatures.

Definition
- Capability of a single genotype to produce various phenotypes in response to differing conditions.
Climate Change Responses
- Acclimation, acclimatization, and learning strategies can help species adjust to environmental changes.

Effects of Climate Change
- Milder winters leading to body mass reduction ultimately affecting sheep physiology and fitness.
- Changes noted in hindleg length and body weight due to less reliance on fat reserves.

Summary of migrations and adaptations highlights the critical balance between human impacts and mammalian adaptations. (Visit Mentimeter with code: 2690 4636 for additional insights.)