What is Behavior?

Behavior is everything an animal does and how it does it.

Ethology is the scientific study of how animals behave. The foundations of behavioral ecology were established by: von Frisch Lorenz Tinbergen

Behavioral ecologists distinguish between proximate and ultimate causes of behavior. Proximate – focuses on environmental stimuli that trigger behavior; the “how” questions. Ultimate – addresses the evolutionary significance of a behavior; the “why” questions (Why did natural selection favor this behavior?)

Classic Demonstration of Innate Behavior

Fixed Action Pattern (FAP): A sequence of unlearned behavioral acts that is essen- tially unchangeable and, once initiated usually carried to completion. This is triggered by an external sensory stimu- lus known as a sign stimulus.

Niko Tinbergen’s Research

Geese Imprinting

Imprinting – a type of behavior that includes both learning and innate components and is generally irreversible. has a sensitive period

Imprinting: Konrad Lorenz with imprinted geese

Conservation biologists have taken advantage of imprinting In programs to save the whooping crane from extinction Figure 51.6

Many behaviors have a strong genetic component.

Kinesis Taxis

Taxis – a more or less automatic oriented movement toward or away from a stimulus Ex: phototaxis in insects towards or away from light Ex: trout facing the current Kinesis – an increase or decrease in activity when stimulus intensity increases Ex: more movement by insects in moist soils

Migration Many features of migratory behavior in birds have been found to be genetically programmed Figure 51.8

Environmental Cues: sun, stars, earth’s magnetic field, landmarks Many features of migratory behavior in birds have been found to be genetically programmed Environmental Cues: sun, stars, earth’s magnetic field, landmarks Figure 51.8

Signals and Communication Nocturnal animals use auditory and chemical signals Diurnal animals use visual and auditory signals

Courtship behavior of fruit flies Signal: stimulus that causes a change in behavior; basis of animal communication Pheromones – chemicals emitted by members of one species that affect other members of the species (eg. Queen bee, fruit fly, fish, termites, trees, humans) Visual signals – eg. Warning flash of white of a mockingbird's wing Tactile (touch) – eg. Male fruit fly taps female fly Auditory signals – screech of blue jay or song of warbler Courtship behavior of fruit flies

Staking Out Territory With Chemical Markers

Honeybee Dance Language (von Frisch) Used to inform other bees about distance and direction of travel to food sources

Circadian Rhythm: internal biological clock The circadian clock in the hamster brain signals a change in coat color according to season by releasing the hormone melatonin. The Suprachiasmatic nuclei (SCN) region is located in the hypothalamus of the brain. The SCN sends signals throughout the body in response to dark and light. Plants can have two internal clocks: one sensitive to light and the other sensitive to temperature More on Clock Genes: http://learn.genetics.utah.edu/content/inheritance/clockgenes/

Genetic Influences on Mating Seen with prairie voles Male prairie voles help to care for the young which is unusual since few mammals are monogamous

Environment, along with genetic makeup, influences the development of behaviors Ex: The diet of the larvae of Drosophila influences mate choice later in life

Proportion of matings by Sonoran females Figure 51.12 EXPERIMENT RESULTS The difference in mate selection shown by females that developed on different diets indicates that mate choice by females of Sonoran populations of D. mojavensis is strongly influenced by the dietary environment in which larvae develop. 100 75 50 25 Artificial Organ pipe cactus Agria cactus Culture medium Baja males Sonoran males (b) Proportion of matings by Sonoran females (a)

Learning What is the difference between instinctive behavior and learned behavior?

Habituation Loss of responsiveness to stimuli that convey little information ex: you continually drive over the speed limit on the freeway and never get a ticket; therefore there is no reason to change your driving habits.

Spatial Learning Cognitive Map: internal representation of spatial relationship among objects in an animal’s surroundings Birds use spatial maps to relocate nut caches

Tinbergen’s experiments on the digger wasp’s nest-locating behavior – the wasps use landmarks to keep track of their nests

Other ways in which behavior is influenced: Classical Conditioning Associative Learning Classical Conditioning

Operant Conditioning (Trial and Error Learning)

Two Kinds of Bird-Song Development: The Songs of Most Bird Species Are at Least Partly Learned

Cognitive Ethology – young chimps learning to crack oil palm nuts

“Fishing” by a Chimpanzee

Female warblers prefer males with large song repertoires

Behavioral traits can evolve by natural selection.

Feeding by Young Bluegill Sunfish Supporting Optimal Foraging Theory

Mating Behavior Promiscuous Monogamous Polygamous Polyandrous – single female with several males Polygynous – single male with several females

In monogamous relationships One male mates with one female Figure 51.25a (a) Since monogamous species, such as these trumpeter swans, are often monomorphic, males and females are difficult to distinguish using external characteristics only.

Red – Handed Tamarin Tamarins -the only non-human primates that exhibit polyandry.

Sexual Selection – a form of natural selection in which differences in reproductive success among individuals are a consequence of differences in mating success; proposed by Charles Darwin

Phaloropes

Peahen Peacock Female Cardinal Male Cardinal

Golden Silk Spiders in Costa Rica

Territoriality: Mountain Goats and Stallions

Agonistic Behavior Contest that involves threatening and submissive behavior to gain access to a resource (food or mate) What is the evolutionary importance of agonistic behavior?

Agnostic Behavior

Ritual Wrestling by Rattlesnakes

Inclusive Fitness What is altruism?

Social Behavior and Social Systems Are Shaped by Natural Selection Altruistic acts— behaviors that reduce the performer’s fitness, but increase fitness of the individual being helped. An animal’s offspring contribute to its individual fitness. Inclusive fitness is individual reproductive success plus that derived from relative’s success.

Altruistic Social Behavior Altruism = selfless behavior Reduce individual fitness but increase fitness of others in population i.e. bee societies; naked mole rats Inclusive fitness: total effect of producing own offspring (pass on genes) + helping close relatives Kin selection: type of natural selection; altruistic behavior enhances reproductive success of relatives

Leads to kin selection and coefficient of relatedness

Kin Selection is selection for behaviors that increase a relative’s success, at a cost to the performer. Scrub jays demonstrate helping at the nest. Helpers are young, prior offspring of the mating pair Mating pairs with helpers have increased reproductive success

Kin Selection and Altruism in the Belding Ground Squirrel-Females stay closer to the burrows

Altruistic Behavior in the Belding Ground Squirrel

Vervet Monkeys Learn Correct Use of Alarm Calls