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^{\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.