Animal Behavior Notes

Fields of Behavior

  • Animal behavior encompasses various fields, including:
    • Animal Behavior
    • Behavioral Ecology
    • Ethology
    • Neurobiology
    • Neuroethology
    • Neuroscience
    • Psychology
    • Sociology
    • Anthropology
    • Cognitive Science
    • These fields span biological and social sciences.

Ethology

  • Ethology emerged in the 1930s-1960s.
  • Key figures:
    • Konrad Lorenz: Studied imprinting and stimulus-response.
    • Niko Tinbergen: Focused on stimulus responses in simple reflexive behaviors and developed an early version of levels of analysis.
    • Karl von Frisch: Known for his work on the waggle dance and social behavior of honey bees.

Stimulus Response: Stimuli

  • The environment is complex, but animals may perceive it in a simpler manner.
  • Animals may focus on one component of a complex pattern, such as:
    • Rate of movement (irrespective of what is moving).
    • A particular color or pattern.

Stimulus Response: Responses

  • Instinctive vs. learned behavior.
  • Early ethologists believed most animal behavior is instinctive, fixed, and inflexible.
  • Specific stimuli elicit fixed, instinctive responses.

Usefulness of Stimulus-Response Model

  • The stimulus-response model, though simplified, is useful.
  • Adaptations rely on the simplicity of this model.
  • Many examples exist, especially in insects.

Tinbergen: Superstimulus

  • Tinbergen studied superstimuli, exaggerated stimuli that elicit a stronger response than the natural stimulus.

Imprinting

  • Imprinting is a form of learning where young animals form an attachment to the first moving object they see, typically their parent.

Geese Eggs

  • Lorenz's famous studies involved geese eggs, where newly hatched goslings imprinted on him.

Central Pattern Generators

  • Nerves are organized into fixed circuits that control stereotyped periodic behavior like walking.
  • They function independently of sensory inputs.
  • Neuron A connects to B to C to D, etc., in a clock-like fashion.
  • Thousands of neurons can be involved.
  • The circuit repeats with the period of the behavior to create a rhythm.

Significance of Central Pattern Generators

  • Behavior can be seen as complex; however, some behaviors are simple and compartmentalized.
  • The reductionist approach, central to biology, works on behaviors broken down into small simple pieces.
  • Lorenz and Tinbergen brought animal behavior into the mainstream of biology.

Behavioral Ecology

  • Behavioral Ecology lies at the intersection of ecology, behavior, and evolution.
  • A behavior is only adaptive within a particular ecological context.
  • Ecology defines selective pressures that drive the evolution of behavior.

Metallic Beetles and Coke Bottles

  • Example: Metallic beetles were attracted to discarded coke bottles due to their reflective properties, mistaking them for potential mates, illustrating maladaptive behavior in a changed environment.

Jewel Beetles

  • Using orange color and dimpled texture as mating cues was adaptive for jewel beetles in central Australia because nothing else looked like this.
  • Evolution favors simple and cheap cues.
  • When the environment changed (introduction of beer bottles), this behavior became maladaptive.

Daphnia Spines

  • Daphnia ambigua sometimes have helmets and spines.
  • This varies with place and season.
  • This phenotypic plasticity is controlled by environmental cues.
  • Phenotypic plasticity refers to variable traits in the same organism.
  • Question: Why is the helmet adaptive?

Previous Work on Daphnia

  • Helmets only form at about 11∘11^{\circ} Celsius.
  • Turbulent water produced helmets (small ones).
  • The consensus was that helmets were caused by physical factors (Hebert and Grewe, 1985).

Hypotheses on Daphnia

  • More recent work (circa 1985) showed that the presence of predatory insect larvae induced defensive morphology in other daphnia species.
  • Test the same hypothesis for Daphnia ambigua:
    • Chemical cues in the water released from predatory insect larvae induce defensive phenotypic plasticity in the daphnia.

Methods on Daphnia

  • Wild-caught daphnia from different regions were grown in the lab.
  • Chaoborus (predatory insect) were collected and boiled in water to release chemicals.
  • Daphnia were raised in cups of water with and without Chaoborus extract.

Results on Daphnia

  • Helmut length was measured in daphnia raised with and without predator cues from different lakes (Collins Lake, St. Louis, Lake Poinsett).
  • Graphs showed the relationship between Helmut length and Body Length across conditions.

Conclusions on Daphnia & Behavioral Adaptations

  • Ecological environments are critical to behavioral adaptations.
  • Behaviorists study the morphology underlying behavior (color patterns, sensory abilities, morphology, etc.) as well as behavior.
  • Typically, such adaptations are fixed but phenotypical plasticity attracts more attention.
  • The cues used are simple.
  • The landscape (biotic or abiotic) is vast, but the relevant information to the animal is simple.
  • A signal or cue is a simple reliable indicator of a more complex pattern.

Sociobiology

  • Sociobiology: The New Synthesis was a 1975 book by E.O. Wilson.
  • It summarized the knowledge of animal behavior to date.
  • It argued that the knowledge gained could be applied to human behavior.

Sociobiology Pros

  • Gave rise in part to fields such as biological anthropology and evolutionary psychology.
  • The behavioral ecology approach (evolutionary basis of behavior) is applicable to some human behavior.

Sociobiology Cons

  • Much of human behavior is based on learning.
  • Behavioral ecologists study genetically based adaptations.
  • This makes applying it problematic.
  • Human behavior is much more complex than animal behavior, and new tools are necessary.
  • Maladaptive behavior is common in humans (e.g., spite).

Animal Behavior Today

  • The class will touch on most of the topics currently popular in behavior.
  • Social behavior and reproductive behavior dominate the field.
    • Social behavior: Social insects loom large.
    • Reproductive behavior: Birds loom large.

Animal Behavior: Adaptive vs. Novel Environments

  • Behavioral Ecology focused on adaptive behavior and implies a long evolutionary history.
  • Novel environments are different, with raw variation rather than adaptive traits.

Evolutionary Theory and Behavior

  • Evolution is not always a useful theory for understanding behavior.
  • Adaptation is simple, while maladaptive and neutral traits are harder to explain.
  • Not always evolutionarily grounded.
  • Behavior can be biologically based but not evolutionarily explainable.

Urban Ecology

  • Many behaviorists now study animals living in anthrocentric environments (cities, farms, etc.).
  • The behavior is a complex mixture of adaptive, maladaptive, and neutral behavior.
  • In general, the notion that one must find a “natural” environment to work in has gone away.