Behavioral Ecology Behavior an action the response to a stimulus 1019 1035 studies on genetics hormonal and neural signaling natural selection evolutionary history and ecological interactions Proximate mechanistic causation explains how actions occur in terms of neurological hormonal and skeletal muscular mechanisms involved Ultimate evolutionary causation explains why actions occur based on evolutionary consequences and history is behavior due to ancestors is it adaptive increasing the individual s fitness Observing a Spiny Lobster hide in cracks in coral reefs during the day and hunt for food at night find their way back through receptors in their brains detecting the Earth s magnetic field proximate causation navigating abilities allow for hunting at night and safety from predators during the day ultimate causation decisions are due to evolution shaped genome to direct the nervous and endocrine system to take in information and direct behavior that ll direct the genome on to the next generation Conditional Strategies and Decision Making Fixed action patterns FAPs highly inflexible stereotypes behavior patterns innate behavior Innate behavior inherited little variation based on learning or the individual s condition rare Most behavior is flexible and condition dependent behavior changes in response to learning and shows flexibility in response to changing environmental conditions animals have a range of actions in response to a situation so they take in info from the environment and make a decision about what to do Cost benefit analysis decisions analyses that weigh the fitness costs and benefits of a particular action note decisions made by non human organisms are not conscious What Should I Eat Foraging when animals seek food Sokolowski noticed rovers moved after feeding at a particular location and sitters stayed put among fruit fly larvae offspring tended to follow suit rovers were rovers etc Experiment Found and cloned a gene associated with the rover sitter difference named foraging for protein product of for is involved in the response to a cell cell signal Conclusion rovers and sitters tend to behave differently while foraging due to different alleles of the for gene homologous genes to for are found in honeybees and roundworm Caenorhabditis elegans Scientists are focusing on finding out which signaling pathway associated with feeding or nervous system development uses the for gene and why different alleles change feeding behavior Results Sokolowski showed that rover allele is favored when high pop density and short food supply and sitters vice versa presence of certain alleles is responsible for a difference in fitness in specific types of habitats Optimal foraging animals maximize their feeding efficiency adult Drosophila make decisions larvae don t Studied white fronted bee eaters some travel far away for food others stay close to colony stay longer if food is far away and come back with more optimal foraging Sexual Activity in Anolis Lizards Jan males establish breeding territories Feb females become active April mating season begins Sex hormones testosterone and estradiol cause dramatic seasonal changes in behavior levels induce sexual activity during appropriate time of the year optimal for offspring to develop Crews experimented with five test groups lengthening the days showing arrival of spring females exposed to springlike conditions began producing eggs other females didn t females exposed to breeding males began to produce eggs others didn t RESULTS females need to experience springlike light and temps and exposure to breeding males Visual stimulation from dewlap brightly colored flap of skin of males triggers the hormone production and onset of sexual behavior Female Barn Swallows pickiest when choosing mates look for males that contribute good alleles and or resources to their offspring prefer to mate with male swallows with long tail feathers ANIMALS MAKE DECISIONS IN A WAY THAT MAXIMIZES THEIR FITNESS Navigation 1 piloting use of familiar landmarks a offspring follow their parents S in fall N in spring and often memorize the route 2 compass orientation movement that s oriented in a specific direction compass a use the Sun during the day and the stars at night to determine where N is b circadian clock maintains a 24 hour rhythm of chemical activity set by light dark transitions of day and night c on cloudy days nights birds orient using Earth s magnetic field 3 true navigation ability to locate a specific place on Earth s surface map Animals Move with Change of Seasons Arctic terns nest in far north tundras one pop flies south along coast of Africa then back north along coast of South America feed on fish available in different parts of the world at different seasons Monarch butterflies spend winter in central Mexico SW California return north in spring and lay eggs on the way adults die on journey and offspring head north higher reproductive success Salmon hatch along Pacific Coast of N America and Asia migrate to the ocean and return to stream where they hatched to mate and die more food available in ocean but offspring have a better chance of survival in freshwater streams Benefits of migration increased access to food but high cost in time energy and predation risk For communication to occur one individual must send out a signal that is received and acted on by another individual Honeybee Language Queen bee lays eggs that are cared for by workers also build and maintain the hive obtain food for themselves and others When a new food source is discovered bees communicate with each other and many other bees show up How they communicate 2 Dance hypothesis von Frisch foragers move in a circular pattern when they return to the hive and they return to food source with more bees hives are dark so workers got info from the dance by touching the dancer and following the dancer s movements 3 Communicating Directions and Distances waggle dance combine circular movements with short straight runs move abdomen from side to side a direction of waggle run correlates with direction of food source b length of the straight waggling run was proportional to the distance the foragers had to fly to reach the feeder Modes of Communication Acoustic song of crickets or birds Visual color patterns of birds or fish Type of signal used correlates with organism s habitat sound travels farther in water hump back wales rely on songs visual communication in open treeless habitats