FW 260 Wildlife Welfare factors Exam 2

Wildlife Welfare Factors

Key resources needed for survival: food, water, cover, space, oxygen

Leopold’s Model

Framework for managing wildlife using key habitat factors and environmental resistance

Game Management

Human effort to maintain wildlife populations after natural systems are altered

Central Question of Wildlife Management

How many animals should be on the landscape

Minimum Viable Population

Smallest population size needed to avoid extinction

Human Tolerance Capacity

Maximum population humans are willing to tolerate

Environmental Resistance

Factors that prevent populations from growing exponentially

Examples of Environmental Resistance

Predation, hunting, disease, parasites, accidents

Decimating Factors

Forces that directly reduce population size

Examples of Decimating Factors

Predation, hunting, disease, starvation, accidents

Welfare Factor Manipulation

Changing resources (like food or space) to increase or decrease populations

Food as Limiting Factor

The most important factor controlling population if others are sufficient

Effect of Increasing Food

Population increases

Effect of Decreasing Food

Population decreases

Nutrition

Process of acquiring and using food for metabolism and survival

Forage

Plant material available for herbivores (browse and herbage)

Food Habits

Diet of an organism and how it changes over time

Factors Affecting Diet

Time of year, life stage, environment, nutrient needs

Matter

Physical material in environment; recycled through ecosystems

Energy

Required for life processes; not recycled

Food Chain

Pathway of energy transfer from producers to consumers

Primary Producers

Organisms (plants) that capture energy from sunlight

Primary Consumers

Herbivores that eat producers

Secondary Consumers

Carnivores that eat herbivores

Second Law of Thermodynamics

Energy transfer is inefficient and loses energy as heat

10 Percent Rule

Only about 10% of energy passes to the next trophic level

90 Percent Energy Loss

Majority of energy is lost at each trophic level

Food Chain Limitation

Energy loss limits the number of trophic levels

Energy Flow Example

Large amount of plant biomass needed to support top predators

Maintenance Energy

Energy needed to maintain body weight and basic function

Growth and Reproduction Energy

Additional energy needed beyond maintenance

Metabolic Rate Relationship

Energy needs increase with body size but not linearly

Small Animal Metabolism

Small animals require more energy per body mass

Bird Metabolism

Small birds have especially high energy needs

Example Energy Needs

Shrew ~2.6 kcal/day vs. bear ~15,000 kcal/day

Optimal Foraging

Animals select foods with highest energy/nutrient value

Diet Shift (Ducklings)

Young eat protein-rich insects, adults shift to plants

Vitamins

Organic compounds needed in small amounts for survival

Coprophagia

Consumption of feces to extract additional nutrients

Rabbit Digestion

Rabbits re-ingest soft feces to obtain vitamins like vitamin K

Minerals

Inorganic nutrients required for body functions

Geophagia

Consumption of soil to obtain minerals

Salt Licks

Areas where animals consume salt/minerals

Risks of Salt Licks

Disease spread, predator attraction, altered behavior

Opportunistic Feeding

Animals eat non-typical foods when beneficial

Example Opportunistic Feeding

Deer eating eggs or bones for nutrients

Calcium Acquisition

Animals consume bones, eggs, or antlers for calcium

Digestive Process

Breakdown of food into absorbable nutrients

Mastication

Chewing food to begin digestion

Saliva Function

Starts chemical digestion of food

Digestive Tract Variation

Different species have different digestive systems

Carnivore Digestion

Shorter intestines, easier digestion of meat

Herbivore Digestion

Longer intestines, break down plant cell walls

Monogastric Stomach

Single-chambered stomach (humans)

Ruminant Stomach

Multi-chambered stomach for fermenting plant material

Ruminant Advantage

More efficient nutrient extraction from plants

Hindgut Fermentation

Less efficient but faster digestion of lower-quality food

High vs Low Quality Diet

High quality food provides more usable energy

Energy Loss in Digestion

Losses through heat, respiration, methane, and waste