F&W ECOL 318 - Exam 1

Aldo Leopold

• Chair of Game Management at UW-Madison in 1933

• Founder of UW’s Wildlife Academic Program

• First Professor of F&W ECOL 318

• Author of Game Management and A Sand County Almanac

• Wilderness Advocate that supported Habitat Conservation

• One of the first to apply the science of ecology to the practice of conservation.

• Started as a Forester

• Believed that we must give wildlife what it needs to thrive.

The Shack

A former chicken coop bought by Aldo Leopold during the Great Depression, which he used as a family retreat and where he did much of his writing.

Ecology

The Study of the…

• Economy of Nature

• Structure & Function in Nature

• Distribution & Abundance of Organisms

• Adaptations of Organisms to their Environment

• Relationships between Organisms and their Environment

Wildlife

Primarily Undomesticated Terrestrial Vertebrates

Definition of Wildlife Ecology

The applied ecology of wild terrestrial vertebrates and their plant and animal associates, as well as the science behind the practice of wildlife management.

Basic Science

Science that increases knowledge & understanding of the universe without immediate benefit or practical application.

Applied Science

Science motivated by a specific need for information.

Basic Ecology

The Study of Ecology with a Primarily Evolutionary Perspective

Applied Ecology Examples

• Natural Resource Management

• Conservation Biology

• Restoration Ecology

• Landscape Ecology

• Agroecology

• Urban Ecology

Definition of Wildlife Management

The art and science of manipulating populations, habitats, and people to achieve some desired outcome.

Goals of Wildlife Management

• Increase Rare or Threatened Species

• Decrease Overabundant, Invasive, or Nuisance Species

• Stabilize Sustainable Harvest of Game Species

• Monitor & Simply Keep Track of Species

Levels of Organization in Ecology

• Individual Organism

• Population

• Community

• Ecosystem

• Biosphere

Individual Organism Ecology

Interactions between Individual Organisms and their Biological & Physical Environment

Individual Organism Properties

• Genotype

• Phenotype

• Physiology

• Morphology

• Anatomy

• Behavior

Population

Group of Individuals of the Same Species in the Same Area at the Same Time

Population Dynamics

Changes in Population Size Over Time

Population Properties

• Size

• Density

• Geographic Range

• Gender Ratio

• Age Structure

• Birth & Death Rates

• Immigration & Emigration Rates

Community

Group of Interacting Species in the Same Area at the Same Time

Community Interaction Examples

• Interspecific Competition (Negative-Negative)

• Predation (Negative-Positive)

• Mutualism (Positive-Positive)

Succession

Variation Over Time in a Community or Ecosystem

Community Properties

• Food Chains & Webs

• Composition

• Structure

• Species Richness: Total # of Species

• Relative Abundance Pattern

• Diversity

• Stability: Resistance to Change & Disturbances

Ecosystem

All Organisms in an Area and their Physical Environment

Biotic Factors

Factors related to Living Organisms

Abiotic Factors

• Soil

• Water

• Climate

• Geology

• Etc.

Ecosystem Properties

• Biotic & Abiotic Factors

• Energy Production

• Nutrient Cycling

• Carbon Sequestration

• Ecosystem Services

Scientific Method

• Make Observation

• Ask a Question (Why is this?)

• Form Hypothesis (Potential Answer)

• Conduct Experiment

• Compare Expected Results to Actual Results

• Support or Reject Hypothesis

  • If Rejected, Form New Hypothesis & Repeat

Occam’s Razor

Idea that the Simplest Answer is Often True

Hypothesis Formation

• Start with Observation of Natural Pattern

• Pose Research Question to Explain Pattern

• Propose Hypothesis as Possible Answer

• Should be Simple, Well-Defined, Testable & Falsifiable

• Hypotheses are Never Proven

• Conduct Experiments & Collect Data to either Support or Refute

Experimental Research

• Look at Response of One Variable to Changes in Some Other Variable(s)

• Compare Manipulated Treatment Groups to Control Groups to measure Magnitude of Treatment Effect

• Only Way to Determine Cause & Effect Relationship

Qualities of a Good Experiment

• Clear Hypothesis

• Systematic Variation

  • Independent Variable/Treatment & Dependent Variable/Outcome

  • Potentially Confounding Variables

  • Experimental Group & Control Group

• Replication

Systematic Variation

Process of Varying One Factor while holding All Other Factors Constant

Independent Variable/Treatment

Manipulated Factor in an Experiment

Dependent Variable/Outcome

Quality measured to determine Effect of Treatment

Potentially Confounding Variables

Factors held Constant to avoid creating Bias in an Experiment

Experimental Group

Group that receives a Manipulated Treatment

Control Group

Group that receives No Treatment & represents Baseline Conditions

Replication

Process of having Multiple Experimental Units

• Avoid Drawing Conclusion from Spurious Result

• Increase Scope of Inference of Experiment

• Determine Degree of Variability in Data

Themes of Ecology of Individual Animals

• Adaptations to Maximize Fitness

• Trade-Offs (Survival vs. Reproduction)

• Economy: Balance Gains & Losses

• Effects of Body Size & Shape

• Effects of Climate

• Differences among Vertebrate Groups

Physiological Ecology Overview

• Study of Physiological Functioning of Organisms in Relation to their Environment

• Process of how Species adapt to Environments & how Environmental Conditions restrict Ranges/Distribution

Examples of Range Limiting Factors

• Temperature, Precipitation, & Amount of Sunlight

• Nutrient Availability & pH

• Other Species

Tropical Rainforest

Biome resulting from Both High Temperature & Precipitation

Tundra

Biome resulting from Both Low Temperature & Precipitation

Subtropical Desert

Biome resulting from High Temperature & Low Precipitation

Evapotranspiration

Movement of Water to Atmosphere due to Evaporation from Ground & Transpiration from Plants

Potential Evapotranspiration (PET)

• Max Possible Evapotranspiration when Water is Not Limited

• Affected by Temperature, Humidity, Wind, Sun, Vegetation Type, Etc.

• About Equal (in Millimeters) to 2 times the Average Temperature in Celsius

Actual Evapotranspiration (AET)

• Actual Amount of Evapotranspiration that takes place given Temperature & Water Availability

• About Equal to PET when Precipitation is Greater than or Equal to PET

• About Equal to Precipitation when Precipitation is Less than PET

• Shown in Climatic Diagrams

Liebig’s Law of the Minimum

Growth & Reproduction are Limited by the Availability of the Scarcest Resource in an Environment

Physiological Tolerances

• Limits on Environmental Conditions that an Organism can Tolerate

• Largely Determines Geographic Range of Species

• Shelford’s Law

Shelford’s Law

Abundance or Distribution of Organism depends on Range of Tolerance for Various Environmental Factors

Reactions to Changing Environments

• Geographic Range Shift

• Extinction/Extirpation

• Acclimation

• Adaptation

Acclimation

Reaction to Changing Environment & Adjustment of Environmental Tolerances that occurs within an Individual Organism

Adaptation

Reaction to Changing Environment & Adjustment of Environmental Tolerances that occurs within a Population over Generations

Overview of Adaptations

• Any Heritable Trait that Increases an Individual’s Fitness

• Behavioral = Evolved Action

• Morphological = Evolved Structure

• Physiological = Evolved Bodily Function

• Must Consider Trade-Off between Reproduction & Survival

Fitness

Genetic Contribution of an Individual to Future Generations

• Trade-Off: Maximize Number of Offspring vs. Maximize Offspring Survival

Homeostasis

• Maintenance Constant Internal Conditions Independent of the External Environment

  • Internal: Contant Temperature & Chemical Composition, Low Entropy

  • External: Highly Variable, High Entropy

• Effected by Surface Area-to-Volume Ratio

Surface Area-to-Volume Ratio

• More Exposure to Environment when High, resulting in More Heat & Water Loss

• Decreases as Body Size Increases

• Important in Homeostasis

• Surface Area = ~π(l²)

• Volume = ~(π/6)(l³)

Water Budget Inputs

• Ingestion: Water from drinking or from eating high moisture-content foods.

• Metabolic Water: Byproduct of Breaking Down Nutrients

  • Breakdown of Glucose produces CO₂, Water, & Energy

  • More Water produced from Breakdown of Fat

Water Budget Outputs

• Secretion: Elimination of Waste Products (Urine + Feces)

  • Uric Acid: Secreted by Birds & Most Reptiles, Uses Less Water to Excrete

  • Urea: Secreted by Mammals & Most Amphibians, Less Energy to Produce

• Evaporation: Water Lost directly from Skin or Respiratory Tract

  • Includes Evaporative Cooling like Panting & Sweating

Osmotic Exchange

• Water Input or Output

• Direct Absorption/Loss of Water through Osmosis in Aquatic Animals

• Water absorbed in Freshwater

• Water lost in Saltwater

• Important in Fish

• Insignificant in Terrestrial Animals

Complete Water Budget

• W_net = Inputs + Outputs

• W_net = W_ing + W_met ± W_osm - W_sec -W_evap

Behavioral Desert Adaptations

• Nocturnal: Active at Night

• Live in Burrows

• Seek Food with High Preformed or Metabolic Water Content

• Aestivation: Summer or Dry Season Dormancy

Morphological Desert Adaptations

• Body Parts adapted for Fat Storage

  • Camel Hump, Thick Tails

• Long Extremities for Dissipating Heat

  • Big Ears in Elephants & Foxes

• Gloger’s Rule

Gloger’s Rule

Endotherms of a Given Species tend to be Darker in Color in Humid Environments & Lighter in Color in Arid Environments

Physiological Desert Adaptations

• Dry Feces

• Concentrated Urine due to Long Loops of Henle

• Cooling & Condensation in Nasal Passages to reduce Water Loss during Exhalation

Marine Environment Adaptations

• Salt Glands in Reptiles & Birds

• Produce Concentrated Urine

• Avoid Drinking Sea Water

• Milk of Lactating Mammals Very Concentrated

Methods of Thermoregulation

• Endothermy vs. Ectothermy

• Homeothermy vs. Poikilothermy

Endotherms

Animals like Mammals & Birds that have an Internal Heat Source

Ectotherms

Animals like Reptiles & Amphibians that rely on an External Heat Source

Homeotherms

Animals that maintain a Relatively Constant Body Temperature

Poikilotherms

Animals with a Body Temperature that varies with the Environmental Temperature

Advantages of Endothermy

• Tolerate Wider Range of Conditions

• Can be Active Day or Night & Year Around

• Aerobic Metabolism sustains Longer Activity

Advantages of Ectothermy

• Greater Efficiency & Lower Energy Demands

• Able to Survive Long Periods of Low Food Availability

• Little Movement Required

• More Energy towards Growth

Metabolic Rate

Rate of Heat Production or Energy Expenditure

Basal Metabolic Rate (BMR)

Standard & Lowest Rate of Energy Expenditure of Resting & Fasting Animal in its Thermoneutral Zone or Comfortable Temperature Range

Thermonetural Zone (TNZ)

The Temperature Range over which a Homeotherm can maintain a Constant Body Temperature without raising its Metabolic Rate

• About 65 to 75 Degrees Fahrenheit for Humans

• No Matter the Environmental Temperature, a Stress Response leads to an Increase in Metabolic Rate & Temperature

Heat Budget Inputs

• Absorbed Solar Radiation: Heat Gained depends on Exposed Surface Area, Intensity of Solar Radiation, & Proportion of Radiation Absorbed

• Metabolic Rate: Generated through Energy Expenditure

  • Increases with Body Size & Activity Level

Heat Budget Inputs or Outputs

• Thermal Radiation

• Conduction

• Convection

Thermal Radiation

• Heat Budget Input or Output

• Heat Emitted & Absorbed from Surroundings

• Depends on Body Temperature, Surface Area, & Emissivity

Conduction

• Heat Budget Input or Output

• Transfer of Heat between Touching Surfaces

• Depends on Relative Temperature of Surfaces

  • Warmer Surface loses Heat, Cooler Surface gains Heat

Convection

• Heat Budget Input or Output

• Transfer of Heat between Body & Surrounding Fluid like Air or Water

• Depends on Relative Temperature of Body & Fluid

• Rate of Transfer increases with Wind Speed

Evaporative Cooling

• Only True Heat Budget Output

• Heat released when Water changes from Liquid to Gas

• Decrease Body Temperature by Sweating or Panting

Heat Balance Equation

• H_net = Inputs - Outputs

• H_net = H_sr + H_met ± H_tr ± H_cond ± H_conv - H_evap

Bergmann’s Rule

Individuals of a Given Species are Larger in Cold Climates than in Warm Climates

Allen’s Rule

Individuals of a Given Species or Taxa have Shorter Extremities in Cold Climates than in Warm Climates

Inefficiency of Food Consumption

• 2nd Law of Thermodynamics: Some Energy is Always Lost as Heat

• Net Energy = Gross Energy - Cost of Extraction - Feces - Urine

  • Net Energy about 10% of Gross Energy for Endotherms

• Must obtain Correct Nutrients

Self-Maintenance

• Use of Most Net Energy

• Includes Cellular Activity required to maintain Basal Metabolic Rate

• Includes Physical Activities required for Survival

• Energy Demands: Foraging, Food Processing, Predator Avoidance, Growth, Locomotion, Thermoregulation, & Molting

Energy Demands of Self-Maintenance

• Foraging for Food

• Processing/Digesting Food

• Avoiding Predators

• Growth

• Locomotion/Movement

• Thermoregulation

• Molting/Shedding of Parts

Reproduction

• Use of Left-Over Energy after Self-Maintenance Needs are Met

• Trade-Off: Use of Energy reduces Survival Odds

• Foregone when Short on Energy

• Typically Occurs when Food & Energy most Abundant

• Energy Demands: Courtship, Territory Defense, Nest/Den Construction, Gamete Production, Gestation, Egg Laying or Birth, Lactation, & Parental Care

Energy Demands of Reproduction

• Finding & Courting a Mate

• Defending Territory

• Constructing a Nest or Den

• Producing Gametes

  • Much Greater Cost to Females

• Gestation

• Laying Eggs or Giving Birth

• Lactation & Feeding Young

• Parental Care

Time-Energy Budget

• Record of How an Animal divides its Time & Energy Expenses among Different Activities to maximize Net Energy Gain

• Studies show Animals prioritize Activities in Predictable Ways to Maximize Efficiency

• Time Budget: Observe Animals in Field & Record how much Time they spend on Different Activities

• Energy Expenditure: Measure Rate of Oxygen Consumption as an Animal runs, flies, or swims in Lab