Exam 4 Biol 1108 Uconn

What is behavioral ecology?

 The study of the adaptive value of behavior in its ecological context.

What are Tinbergen’s four questions?

1. Mechanistic (Causation) – How is the behavior caused? (neural, muscular, hormonal mechanisms)
   
   

2. Developmental (Ontogeny) – How is the behavior acquired during an individual’s lifetime?
   
   

3. Adaptive (Function) – How does the behavior increase survival/reproduction?
   
   

Evolutionary (Phylogeny) – How did the behavior arise in evolutionary history?

What are proximate explanations of behavior?

Short-term, within-lifetime processes: mechanistic and developmental.

What are ultimate explanations of behavior?

Long-term evolutionary processes: adaptive and evolutionary history.

Example: Why does a bird sing? (Name all four explanations)

• Mechanistic: Brain circuits, hormones, muscles.
  
  

• Developmental: Learned from adults during critical period.
  
  

• Adaptive: Attracts mates/defends territory.
  
  

Evolutionary: Evolved from ancestral communication systems.

What is the difference between innate and learned behavior?

• Innate: Instinctive; performed without prior experience.
  
  

• Learned: Depends on an individual’s experiences.
  
  

What is a fixed action pattern (FAP)?

A stereotyped, automatic behavior sequence that runs to completion once triggered.

What is a key stimulus?

 The specific signal that triggers a fixed action pattern.

What is a supernormal stimulus?

An exaggerated stimulus that elicits a stronger response than the natural stimulus.

What are displays?

Species-specific, repeatable communication behaviors (e.g., courtship dances).

What are feature detectors?

 Specialized sensory receptors that respond to specific, important environmental signals.

 Example of feature detectors in frogs?

 Female frogs detect male calls with specific pitch, duration, and pulse frequency.

 How do hormones influence behavior?

They produce long-lasting effects, modifying reproductive and social behaviors.

Example of hormones affecting behavior in lizards?

 Male courtship triggers female hormone production → ovary development.

How does removing male testosterone affect female lizards?

Castrated males don’t stimulate female reproductive cycles.

What do breeding experiments tell us about behavior?

They reveal the genetic basis of behavioral traits (e.g., lovebird nest-building).

 Example of a single gene influencing complex behavior?

Fruit fly foraging gene:

• Rover larvae move more.
  
  

Sitter larvae move less.
Different alleles → different feeding behaviors.

Example: Prairie voles vs. meadow voles behavior?

Monogamy vs. promiscuity due to differences in ADH hormone receptor distribution in the brain.

What is nonassociative learning?

 Learning without linking two events.

Define habituation.

Reduced response to a repeated, harmless stimulus.

Define sensitization.

ncreased response after a strong or novel stimulus.

What is associative learning?

Learning that links two events together.

What is classical conditioning?

Associating two stimuli (e.g., Pavlov’s dogs: bell + food → salivation).

What is operant conditioning?

Learning through reinforcement/punishment of behavior.

Why is learning considered an adaptation?

 It increases fitness by allowing flexible responses to environmental change.

 What is taste aversion learning?

 Strong associative learning linking taste → nausea; species-specific capacity.

 What is imprinting?

Rapid learning during a sensitive period early in life.

 What is filial imprinting?

Offspring learn to recognize parent figure (e.g., ducklings following first moving object).

What is orientation?

Directed response to a stimulus.

What is kinesis?

Random movement not oriented toward/away from stimulus.

What is taxis?

 Directed movement toward/away from a stimulus (positive or negative).

What is navigation?

Using a sense of direction + map to reach a goal (e.g., homing pigeons).

What is map information?

Awareness of current location relative to destination.

How do animals navigate?

• Sun compass
  
  

• Stars
  
  

• Earth’s magnetic field
  
  

Landmarks

 What is a lunar clock?

Behavior timed to moon phases (tidal cycles).

Phenotype

Behavior is considered part of an organism's phenotype and is shaped by genes and the nervous and endocrine systems.

Proximate Causation

Focuses on how a behavior occurs: Causation (e.g., stimuli, physiology) and Development (e.g., learning, innate components).

Ultimate Causation

Focuses on why a behavior occurs: Adaptive Function (e.g., increasing survival/reproduction) and Evolutionary History (e.g., phylogeny, selection).

Fixed Action Pattern (FAP)

A sequence of unlearned (innate) behaviors that is essentially unchangeable and invariant, often triggered by a sign stimulus

Sign Stimulus

The external sensory cue that triggers a Fixed Action Pattern (FAP). Example: The red underside of an intruder fish causing a male stickleback to attack, as described in the web page.

What is ecology?

 The study of how organisms interact with each other and with their physical environment.

What are abiotic factors?

Non-living environmental factors like temperature, wind, or water availability.

What are biotic factors?

Interactions with living organisms, including competitors, predators, parasites, prey, and organisms that provide food or shelter.

 What is a population?

All individuals of a species that live and reproduce in a particular place.

What are the three main features of a population?

Size, range, and density.

What are the three main patterns of population distribution?

Clumped, random, and uniform.

What does random population distribution mean?

The location of one individual has no influence on where the next will be found.

When are organisms clumped?

When grouping provides advantages such as protection or increased success.

Why might a population be uniformly distributed?

To prevent others from settling nearby, such as when individuals compete for resources.

How do ecologists estimate population size?

By sampling portions of a population.

 What is mark-and-recapture?

 A method where individuals are captured, marked, released, and later recaptured to estimate population size.

What four factors affect population size?

Births, deaths, immigration, emigration.

 What is the formula for population change?

 ΔN = N₁ − N₀

Expanded population change formula?

 ΔN = (B − D) + (I − E)

What is per capita growth rate (r)?

The rate of population growth per individual: r = (ΔN/Δt) / N

What does it mean if r is positive?

The population increases.

What type of growth occurs when r is constant?

 Exponential growth.

What is the differential equation for continuous exponential growth?

 dN/dt = rN

What is rₘₐₓ (intrinsic rate of increase)?

The maximum per capita growth rate when no environmental factors limit reproduction.

When does exponential growth typically occur?

 When populations are small and resources are abundant.

What is discrete population growth?

Growth in steps, often in species that breed seasonally.

: What is carrying capacity (K)?

 The maximum number of individuals an environment can sustain indefinitely.

 What is logistic growth?

Population growth that slows as size approaches K; forms an S-shaped curve.

Density-dependent factors?

Factors that change with population density, like competition, predation, and disease.

Density-independent factors?

Factors not influenced by density, such as drought or natural disasters.

 What is age structure?

 The number of individuals in each age group of a population.

What does a triangular age structure indicate?

A growing population with many young individuals.

What does a rectangular (even) age structure indicate?

A stable population.

What does an inverted triangle age structure indicate?

 A declining population with many older individuals.

What is demography?

The study of population size, structure, and distribution over time.

What is a cohort?

A group of individuals born at the same time.

 What do survivorship curves show?

How survival probability changes over an organism’s lifespan.

 What are the three types of survivorship curves?

Type I, Type II, Type III.

 What do reproductive patterns reflect?

 How predictable or variable a species’ environment is.

Counting

Useful for sessile (sedentary) organisms within a defined area.

Mark-and-Recapture

Useful for mobile organisms; an extrapolation method.

What is a niche?

 A complete description of a species’ role in its environment and its abiotic/biotic requirements.

What does the niche include?

Climate, habitat, resources, diet, and how the organism lives.

Are niche and habitat the same?

 No. Habitat = where an organism lives; niche = how it lives + all requirements.

What is the fundamental niche?

The full range of climate conditions and food resources a species could use.

What is the realized niche?

The actual area/resources a species uses due to competition or predation.

: Why is the realized niche smaller than the fundamental niche?

Other species restrict access through competition or predation.

 What is phylogenetic niche conservatism?

 Closely related species share similar niches due to inheritance from a common ancestor.

 What is an antagonistic interaction?

 An interaction where at least one participant loses more than it gains.

What is competition?

When two individuals or species use the same resource, lowering its availability.

What is intraspecific competition?

Competition within the same species.

What is interspecific competition?

 Competition between different species.

What is competitive exclusion?

When one species prevents another from occupying a niche or habitat.

 What does competitive exclusion imply about niche overlap?

Two species cannot occupy the exact same niche indefinitely.

 What is resource partitioning?

Species evolve to use different resources or areas to reduce competition.

How does resource partitioning relate to speciation?

Reduced overlap → divergence → possible speciation.

 What is predation?

 One organism (predator) consumes another (prey).

How does predation affect communities?

Predators limit prey populations, preventing competitive exclusion.

 What is parasitism?

One organism lives on/in another, gaining nutrients without usually killing the host.

How do parasites reduce host fitness?

They lower reproduction and survival ability.

What is herbivory?

 Consumption of plant tissues.

 What is mutualism?

Interaction where both species benefit (+/+).

What benefits can mutualisms include?

Nutrients, shelter, reproduction, protection.

Why are mutualistic interactions still subject to natural selection?

 Each species acts in its own best interest and bears costs.

What is symbiosis?

A close, often long-term interaction between two species.