Animal Behavior Test #3 Flashcards
Foraging using a variety of sensory modalities
how animals find food
Search Image
distinctive visual features of an object, like a single prey type; facilities ability to find cryptic prey
Is bumblebee foraging more efficient when multiple senses are used?
trained bumblebees to forage on flowers with different shapes/colors (visual cues) and odor (chemical cues)…bees trained on both visual and odor cues had the highest feeding performance (use of multiple sensory cues facilitates efficient feeding)
Blue jays using search image to find cryptic moths
trained blue jays to search for images of moths (2 species; one cryptic on oak, one cryptic on birch) on computer screen
-run treatment: birds were exposed to the same cryptic moth repeatedly )percent of correct responses increased)
-non run treatment: two different moths were interspersed and presented randomly (the percent of correct responses did not change over trials)
-jays used search image when the same cryptic prey was presented repeatedly, resulting in a more efficient search
Optimality Theory
predicts that an adaptation should have a greater cost-benefit ratio than any alternatives that have been replaced by natural selection
Optimal Foraging Theory
natural selection favors foraging behavior that maximizes fitness
Optimal Diet Model
predicts the food types an animal should include in its diet
Handling Time
time to manipulate food item prior to consumption
Profitability
energy of food item/handling time
Bobwhites and Covey Size
given benefits and costs, coveys of intermediate size have the highest survival rate (look in PPT for more info)
Optimal Diet Model example with hypothetical food types
diets with the lowest combined search and handling time per item, maximizing the energy intake rate…models are useful b/c they generate explicit predictions that can be tested (look in PPT for more info)
Northwest Crows maximize energy intake
Results:
-larger whelks break with fewer drops
-a 5m drop minimizes handling time
-finding a new whelk (search time) takes more time and energy
-more info on PPT
Sodium limitation and feeding behavior of ants
-ants living in environments where sodium is rare will have a a strong preference for sodium chloride
-ants recruited to NaCl vials more strongly as distance to the road increased
-sodium limitation affects feeding behavior
Optimal Patch-Use Model
predicts how long a forager should exploit a food patch
Diminishing Returns
when a forager enters a food patch, it initially harvests food at a high rate. as the patch is depleted, its harvest rate declines
Cumulative Gain Curve
cumulative amount of energy acquired increases more slowly as more time is spent in food patch
Socially Foraging
animals obtain food from the discoveries of others
Kleptoparasites
animals that obtain food from other individuals
Producers vs. Scroungers
-producers search for food
-scroungers usurp food discoveries from producers
Producer-Scrounger Model
predicts the frequency of each foraging strategy in a group
How long should Ruddy Ducks remain in a single foraging patch?
-model accurately predicted the number of items eaten by most of the ducks
-birds spent more time in patches when travel time was long
-ducks attempted to maximize energy intake while feeding from the artificial patches
Sea star feeding example
-sea stars take several days to feed on a clam
-other marine carnivores steal food while the sea stars are actively feeding
What is the equilibrium frequency of producers and scroungers in spice finches?
cover patches had less scroungers, while uncovered patches more scroungers
Endler’s Stereotypical Predation Sequence
-makes predictions about what predators and prey do during the typical predation sequence as well as how selection should act
-the probability that the sequence will be completed increases as the sequence progresses
-encounter, detection, identification, approach-attack, capture, consumption
Apparent Rarity
change daily or seasonal activity or habitat
Polymorphism
the occurrence of two or more clearly different morphs or forms, also referred to as alternative phenotypes, in the population of a species
Apostatic Behavior
predators go after most common prey type…prey reduce likelihood of encounter through polymorphism
Contrast intensity of selection between predator and prey
-predator fails: loses a meal; expect selection on predators to complete the predation sequence
-prey fails: loses their life; expect selection on prey to interrupt the sequence
-can result in an evolutionary arms race (adaptions of one influence the other)
Crypsis/Cryptic Coloration
-prey reduce the likelihood of detection
Importance of background for crypsis
-crypsis only works against the correct background
Cost of crypsis
-time and energy spent finding the right background
-time spent immobile during the day (not foraging, mating, etc.)
Lures
temps an animal or person to do something or go somewhere else
Batesian Mimicry model, mimic, and dupe
-species gain protection from predation by resembling the defensive signaling of an unpalatable or defended species
-dishonest skill, mimic increases, model decreases, dupe decreases
-can result in arms race (directional selection on signal…improved discrimination between models and mimics
Mullerian Mimicry and stabilizing selection
-several equally unpleasantly tasting species share a color pattern (all species benefit - mutualistic relationship)
-honest signal, mimic increases, model increase, dupe increases
-can result on stabilizing selections on signal and on predator perception
Pursuit-Deterrence Hypothesis
-advertisement behavior informs a predator that it has lost the element of surprise; pursuit is not likely to be successful
Alarm Signal Hypothesis
-advertisement behavior warns conspecifics of a nearby predator
Australian Thorny Devil Example
cryptic sometimes…has to have the correct background
Juvenile crabs complex body color, crypsis, and predation risk
-juvenile body coloration is cryptic on shell-hash substrate and reduces predation risk
-small crabs always preferred the shell-hash in the presence of predators…large crabs showed no preference when predation risk was low, but preferred shell-hash when risk was high
Killdeer Lure Example
-pretends to have a broken wing to deter animals or people from ground nest w/ eggs
Bird poop caterpillar and frog example
-caterpillar and frogs looks like bird poop
-reduces the likelihood of identification by resembling inedible objects
Gazelle stotting and deer tail-flagging
-there was no difference in tail flagging between solitary and social deer
-tail flagging was more frequency as the distance to the deer increased
-data was consistent with the pursuit-deterrence hypothesis
-lost element of surprise so pursuit is likely not successful
Aposematism
bright coloration or conspicuous sounds associated w/ chemical defenses
Startle Display
sudden movement that exposes conspicuous colors or a sound
Alarm Calls
interrupt approach attack by warning conspecifics
Predator Harassment
rapid movement around a predator that may be coupled w/ loud vocalizations
Mobbing Behavior
harassment of a predator by multiple individuals
Mechanical/Behavioral Methods to Avoid Capture
-2 banded armadillo (can roll into ball)
-conch
-pangolin (rolls into ball)
-porcupine (uses spines to deter predation)
Octopus Example
video on PPT
Startle Display examples
octopus, moths, butterflies, caterpillars
Swallowtail butterflies startle display
-latency to attack was longer for live butterfly
-live butterfly exhibited startle response 75% of time it was approached
-birds flew away or hopped back in response to 80% of the startle displays
Alarm call examples
ground squirrels and vervet monkeys
California ground squirrel rattlesnake harassment technique
-the temperature of a ground squirrel’s tail was, on average, 2°C higher when the squirrel harassed a rattlesnake than when it harassed a gopher snake
-California ground squirrels include an infrared component in their harassment of rattlesnakes, presumably by increasing blood flow to the tail, which results in a slowing of the snake attack
Owl Mobbing
-owls moved during 20% of mobbing events
-predation on mobbing species was 10x lower than predation on non-mobbing species
-Mobbing can lead to owl displacement and can reduce predation risk
Examples of mechanical/behavioral methods to avoid capture
porcupine, hagfish, autotomy
Dilution Effect
the probability of dying in a successful predator attack (1/N) is reduced by the presence of others
Selfish Herd Effect
individuals reduce predation risk by moving to the center of a group because a predator is more likely to kill a member near the edge of a social group
Group Size Effect
-vigilance behavior of individuals declines as group size increases
-common pattern in many social species
Killifish shoaling behavior
-killfish prefer to associate with other fish when predation is high, as predicted by the dilution effect
-experiment details on PPT
Puddling behavior in butterflies
-costs of increased appearance outweighed by benefits of being one of many prey individuals
Mayfly dilution effect
-researchers counted number of molts and number of spent/dead adult females; results supported dilution effect
-more info on PPT
Redshank spacing within the flock and the Selfish herd effect
-predicts individuals farther away from flock have a higher chance of being targeted by a predator
Scaled Dove flock size and vigilance
-as flock size increases, scan rate declined and foraging duration increased
-birds at the flock edge had higher scan rate, longer scan duration, and lower foraging duration than birds near the center
-experiment details on PPT
Noxiousness
deters predators with chemical defenses, glandular secretions, and reflex bleeding
Misdirecting Predator Attack
directs predator attack elsewhere with physical abnormalities
Behavioral Trade-Off
sacrificing one behavior for another
Vigilance Behavior
scanning the environment for predators
Noxiousness: Giant Leopard Moth, Horned Lizard
-produce droplets containing noxious chemical defenses (moth)
-reflex bleeding (lizard)
Misdirection: Hairstreak Butterflies
-have false head at their tail to fool predators
-orange and black false eyes, turns it’s “false head” toward the perceived danger, initiates movement of hind wings
Flamingo Vigilance - Feeding Trade-Off
increased vigilance decreases feeding time
Elk Vigilance - Feeding Trade-Off
-elk living in areas w/ and w/o wolf predators
-females spent more time feeding in areas w/ wolves, male behavior did not differ
-females exhibit vigilance-feeding trade-off due to wolves
Male Fiddler Crab Borrow Use - Claw Waving Trade-Off
-treatment plots (mature females tethered in the plot) and control plots (no female)
-flew an artificial predator over each plot
-recorded how long males stayed in their burrow after the attack
-males emerged more quickly when a female was present
-males adaptively adjust their refuge use based on its benefits and costs
Station-Keeping
movements directly related to the acquisition of resources (food, mates basking sites, retreat/refuge sites
foraging, territorial defense, commuting
Commuting
movement between resource patches
Exploratory Forays
movement outside of home range
Dispersal
one-way movement from natal site to new breeding site
Migration
two-way movement between sites
Movement Ecology
the study of the process, mechanisms, and consequences of movement
Movement Ecology (External Factors)
-water
-temp
-intraspecific competition
-interspecific competition
-response to predators or parasites affect patterns of movement
Movement Ecology (Internal Factors)
-forgaing ecology (driven by energetics, physiology, metabolism
-mating system (reproductive cycles (determined by combination of external and internal factors)
-life histories
Movement Ecology (Navigation Capacity)
-orientation abilities
-navigation abilities
-sensory perception (visual, auditory, olfactory, magnetic, etc.
Movement Ecology (Movement Capacity)
method of movement (crawl, run, walk, hop, leap, burrow, swim, glide, climb, slither
Movement Ecology (Lifetime Movement Path)
external factors + internal factors + navigation capacity + movement capacity
Why Move?
-acquisition of resources (food, water, basking sites, hibernation sites, nesting sites, shelter/refuges, anything required for survival and reproduction
Costs of Movement
-energy expenditure, exposure to unfavorable conditions, exposure to predators
-most animals only move when necessary
-species differ in how far or how often they move
Sink Population
habitats in which population cannot survive when they are isolated from other populations
Source population
a high quality habitat that allows the population to increase (lots of juveniles in populations)
Importance of Movement to Population/Metapopulation Dynamics
-population dynamics are closely tied to patterns of movement
-movement from one habitat to another (often high mortalities…usually juveniles)
-metapopulation dynamics: some habitat patches are population by individuals the immigrated from other habitat patches (source-sink dynamics and boom-bust
Importance of Movement to Genetic Structure of Populations
genetic structure of populations is affected by movement (gene flow)
Natal Philopatry (Site Fidelity)
the tendency to return to one’s birthplace
Ex. sea turtles (DNA sequences show genetically distinct even though adults share same feeding grounds)
Effects of Habitat Heterogeneity on Movement and Genetic Isolation
-genetic structure of populations is affected by movement
-significant genetic differentiation among populations isolated in suitable habitat surrounded by less suitable habitat
-makes movement difficult between patches
High vs. Low Dispersal Ability and Habitat Heterogeneity
-low dispersal ability have increased isolation…more vulnerable to habitat fragmentation an local extinction
-high dispersal ability have decreased isolation, less affected by barriers, and have considerable gene flow among local populations
Effects of Habitat Fragmentation and Barriers to Movement
-fragmentation affects ability of individuals to move through the landscape (affect reproduction and survival)
-man-made barriers limit movement between populations, increase mortality among migrating animals, decrease genetic diversity within populations, and leads to extinction of small isolated populations
Methods for Studying Movement
-mark/recapture
-tracking
-VIE marking
-sub Q numbered tagging
-PIT tags
-radio transmitters
-RFID tracking devices
Dispersal Fitness Costs
-takes quite a lot of energy to travel
-travel is associated w/ increased predation risk
Reasons for Dispersing
reduces resource competition and inbreeding
Competition Hypothesis
dispersal functions to reduce competition resources
Inbreeding Avoidance Hypothesis
dispersal functions to reduce inbreeding
Post-Natal (Juvenile) Dispersal
young males of many mammal species disperse at adulthood, but females, may not disperse (reduces inbreeding)
Breeding Dispersal
abandoning one breeding site and moving to another
Win-Stay, Lose-Shift-Pattern
species exhibit site fidelity after a reproductive success and exhibit breeding dispersal after a reproductive failure
Public Information
information obtained from the activity or performance of others about the quality of an environmental parameter or resource
Testing the Competition Hypothesis with Springtails
-experimental chambers of interconnected glass vials with soil (low density: 30,000 individuals and high density: 90,000 individuals)
-counted the number of springtails in the chambers after 3 days
-more springtails dispersed in the high density treatment
-competitor density affects dispersal
Testing the Competition Hypothesis with Northern Goshawks
-food-supplemented treatment: platform with several dead quail and control: platform only
-tracked movement of birds w/ radio transmitters
-control birds dispersed farther than food-supplemented birds
-competition for food affects juvenile bird dispersal
Testing the Inbreeding Avoidance Hypothesis with Meadow Voles
-sibling treatment: 2 males and 2 females and control: 2 males and 2 females, not siblings
-captured and identified all individuals in plowed ground
-more males than females were found captured in plowed ground
-sibling voles dispersed earlier and more often than non-sibling voles
-inbreeding avoidance influences the dispersal behavior of meadow voles
Breeding Dispersal in Dragonflies
-reduced mating success in ten territories (treatment) and kept it high in other (controls)
-recorded number of matings for each male and whether he returned to the same territory or dispersed to a different territory
-control males had higher mating success than treatment males
-mating success affects breeding dispersal: individuals use a “win-stay-lose-shift” strategy when making dispersal decisions
Public Information from conspecifics Affects Breeding Dispersal in Kittiwakes
-treatment patch: removed eggs from all birds (all birds had reproductive failure) and control patches: removed eggs only from focal bird (only focal bird had reproductive failure)
-observed where birds bred the next year
-70% of the control patch birds returned to the same breeding sites
-fewer of the treatment patch birds returned to the same breeding sites
