EEBio Wk8 Notes
EEBio Wk8 Notes Ecology and Evolutionary Biology 100
Popular in Introduction to Ecology and Behavior
Popular in Behavioral Sciences
This 21 page Class Notes was uploaded by Marissa Mayeda on Wednesday February 25, 2015. The Class Notes belongs to Ecology and Evolutionary Biology 100 at University of California - Los Angeles taught by Dr. Johns in Winter2015. Since its upload, it has received 74 views. For similar materials see Introduction to Ecology and Behavior in Behavioral Sciences at University of California - Los Angeles.
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Date Created: 02/25/15
Tuesday February 24 2015 Wk 8 Lect 1 Ecology and Behavior EEB 1OO Philip Johns philipjohns1uclaedu Antipredator behaviors Office hours philipjohns1uclaedu Tue HH 31611OO12OO Wed HH 32811OO12OO Fri HH 31611OO12OO Philip Johns Announcements Extra credit video is due by 01 March Email me the youtube link Worth 0 5 or rarely 10 points total What if optimality fails Consider simpler decision rules Include additional constraints Predation risk Minimum nutrient requirements Avoidance of toxins Consider currency other than profitability Efficiency EgainedEspent Moose Moose feed on aquatic amp terrestrial plants Constraints minimum nutrient uptake Moose feed On forest leaves On aquatic plants Moose have Minimum energy and sodium requirements But limited stomach capacity Forest food is High energy But low sodium Aquatic plants are Low energy Sodiumrich Constraints minimum nutrient uptake Enoughfood Enough sodium Can only eat so much Constraints minimum nutrient uptake Moose maximizing energy intake given constraints Influence apparent patch choice Multiple patches of similar quality RecalllFD What do we expect Whatifweseeanimalsononlyonepatch Tuesday February 24 2015 Tuesday February 24 2015 Can influence apparent patch choice Predator on right hand patch Constraints prey choice vs predation stickleback fish hunt in more dense prey areas if kingfisher predator not around but if predator around changes behavior of prey What do prey do about predators Prey defenses Predator Counterdefenses Evolutionary arms race Prey continually evolve to escape predator Predators evolve to catch prey Leads to more and more effective defenses and counter measures evolving fastest animal on land is cheetah long horned antelope is second fastest these two animals are half a word apart are their speeds coincidence NO used to be cheetahs in north america went extinct but we still have their prey item payoff not the same for prey as opposed to predator What do prey do about predators Prey defenses Predator Counterdefenses Butno ce Lifeordinner principle Life or dinner principle Tuesday February 24 2015 if you re prey very bad to not be able to escape that means death if you are a predator don t have to be able to catch all prey this is why prey species evolve faster Often selection on prey is greater than on predator Prey generation time is often shorter than predator Prey defense may evolve faster Prey defense economics Recall Profitability EiT i Ei Energy from item i Ti time includes Si search time for item i hi handling time for item i Net profitability EiSi hi Prey defenses often increase Si or hi Reduce profitability Predators often have multiple possible prey Small increase in search or handling time can reduce profitability Make alternative prey more profitable by comparison prey doesn t just evolve against predator but also against other prey Crypsis Crypsis ability to avoid detection by other organisms A kind of extreme camouflage Dracolizard glides blends into the bark of tree Phyllium walking sticks Tuesday February 24 2015 lookaeleaves Moth all very effective of not looking like the prey items that they are Experimental test Parus major Three kinds of prey items lnedible twigs brown string in opaque straws Large cryptic prey meal worms in opaque straws Small conspicuous prey12 mealworm in clear straws small prey don t have full return compared to larger prey httpwwwjstororgstable4288seq1pagescantabcontents Experimental test What do we expect Predators should prefer prey with higher profitability E1h1 gt E2h2 gt E3h3 Large prey should be more profitable than small prey BUT birds have to reject twigs vs worms need an encounter rate i items encounteredtime Simulates predator searching for cryptic prey httpwwwjstororgstable4288seq1pagescantabcontents Experimental test Specialists on small conspicuous prey don t waste time searching through twigs itwigs x htwigs time handling twigs But specialists on small conspicuous prey also don t get big cryptic prey Tuesday February 24 2015 Do some algebra Find that animals Should specialize when a specialist does better than a generalist Depends on encounter rates for cryptic vs conspicuous prey items Experimental test What birds do when twigs or large prey are abundant more important to be able to sort through twigs and find prey than choose between smaller and bigger prey if this is the case Crypsis works Blue jays better at finding moths on dark backgrounds than on birch bark Orientation matters moths don t jus look like bark but attempt to act like bark through proper orientation httprstbroyalsocietypublishingorgcontent3641516503 Antipredatory defenses Some defenses influence search time Time spend finding prey Crypsis mimicry adjusting to background Some defenses influence handling time Time spent pursuing subduing digesting prey Protective features like spines Misdirecting an attack Startle displays Antipredatory defenses How does this work Tuesday February 24 2015 three spend stickbacks have three spines populations that live in open water have longer spines compared to more secluded stream sticklebacks evolve these defense to increase handling time for predators httpwwwnaturalhistorymagcomfeatures061488theoriginsofform Antipredatory defenses How does this work shranks put their prey on barbed wire can compare horns of the lizards that they are eating can better catch those with smaller horns seems they are choosing lizards with smaller horns httpswwwyoutubecomwatchvGgB4u6ng2M Antipredatory defenses Eyespots and chicken response bright pink eyespots on moths chicks are afraid of the eyespots make alarm call when spots are visible httpbehecooxfordjournalsorgcontent241305full Antipredatory defenses Eye spots are commonmantidseg mantis show eyespots on abdomen giving them a few seconds to escape startle responses work Why have bright contrasting colors but more importantly perhaps animals have adapted to pay attention to faces especially because of owls predator Butterflies with extra eyespots deter attacks attacked less times Tuesday February 24 2015 httprspbroyalsocietypublishingorgcontent282179820141531 Crypsis can vary with sex amp season Eg rock ptarmigan Why coloration very different dep on male and female and dep on mating season or not females during breeding season at least look more drab in order to hide from predators have to sit and protect eggs at higher risk of predation Aposematism warning coloration Monarch butterflies sequester toxins cardiac glycosides from milkweed parasitoid want to lay eggs in caterpillars these toxins in the skin of the caterpillars ward off predators and stay with them into aduHhood Aposematism warning coloration Na39ive blue jays eat and regurgitate predators must learn to avoid this coloration Predators startled by eyespots What about bright colors amp contrasts Aposematism warning coloration means toxic have bright contrasting colors Milkweed bugs on milkweed plant Often distasteful animals aggregate why are they out in the open stay in groups if predator eats one will know to avoid the others and thus group benefits from the loss of one Tuesday February 24 2015 Mullerian mimicry ALL are toxic and aposematic Named after Mr Muller Heliconius butterflies Toxic aposematism Mutual benefit between model and mimics why predators have to learn color patterns to avoid if learn one avoid all cause convergent evolution Bombardier Beetles Bombardier beetles Brachinini Spray 100 C Explodes out of beetle beetle brightly colored Bombardier Beetles Bombardier beetles Brachinini can adjust where it spray the boiling hot acid from its behinds Mimicry Spicebush swallowtail larvae look kind of like snake Batesian mimicry nontoxic species look like poisonous model predator learns to avoid the model Coral snake L extremely venomous milk snake not Mimic Nontoxicvenomous mimic looks like poisonous model Tuesday February 24 2015 Predators learn to avoid model and mimic benefits Think about relative frequencies Too many mimics mean predators do not learn Only works when mimics are relatively rare Batesian mimicry Cinereous mourner bird chick mimics caterpillar caterpillars have toxic hairs acts like caterpillar in addition to looking like it tucks itself down and wiggles around httpswwwyoutubecomwatchvFwSGk1Y4rY httpwwwjstororgstable 101086679106 Wings mimic ants Ants Why fy has markings on its wings that look like at can look at certain groups of flies that have markings like that Wings mimic spiders Ants Spiders Testing Adaptation Spiders amp Flies True fruit flies Tephritidae often have marks on wings Why Testing Adaptation Spiders amp Flies Notice the markings on the wings hold wings over body and wave them 10 Tuesday February 24 2015 some suggest that the markings are not supposed to look like spiders but are supposed to make the flies look like spiders spiders also wave around like the flies to let others know not to mess with them Testing Adaptation Spiders amp Flies Flies hold wings over backs and wave them Testing Adaptation Spiders amp Flies Jumping Spiders have similar leg patterns Leg waving displays True fruit flies Tephritidae and spiders Do fly wing patterns mimic spiders How could we tell Activity hypothesis flies do not mimic spiders flies mimic jumping spiders to protect selves from predators flies mimic jumping spiders to protect themselves from the jumping spiders Experiment can cover patterns on flies or cutoff wings can have house flies wo markings and the fruit flies one normal house fly one normal fruit fly one fruit fly with patterned wings cutoff same behavior without pattern house fly with surgically replaced wing of fruit fly pattern without behavior Results both pattern and behavior combined protect flies from jumping spiders when test against other predators Activity what kind of mimicry l l Tuesday February 24 2015 Only the top is a wasp Bottom fly L beetle moth batesian mimicry 12 Thursday February 26 2015 EEBio WK8 Lect2 Subject Ecology and Behavior EEB 100 Philip Johns philipjohns1uclaedu Antipredator behaviors Office hours philipjohns1uclaedu Tue HH 31611OO12OO Wed HH 32811OO12OO Fri HH 31611OO12OO Philip Johns Announcements Extra credit video is due by 01 March Email me the youtube link Worth 0 5 or rarely 10 points total Active mimicry Octopus are predators But delicious Flatfish Banded sole Lionfish dangerous Seasnake dangerous httpswwwyoutubecomwatchvtLTWFnGmeg Group defenses Dilution safety in numbers reduces per capita risk Selfish herding prey jockey for safe central positions away from predators Thursday February 26 2015 Predator confusion mass prey movement interferes with predator s ability to catch one Vigilance many prey more likely to detect a predator Mobbing prey attackharass predator together Alarm calling prey alert each other Predator dilution Mayflies Ephemeroptera Emerge in large numbers Predator dilution predator satiation 17year cicadas Gnus dropping foals Bait ball Selfish herding But notice what dolphins can do mud nets httpswwwyoutubecomwatchvbzfqPQmThU Mating systems amp sexual selection Mating systems amp sexual selection Examples pheasant tail feathers willow bird fly around with long tail feathers calf birds have mating call httpyoutubeOJgchd1 R7Et18m47s httpyoutubeOJgchd1R7Et28m httpswwwyoutubecomwatchvW7Qanqupo Thursday February 26 2015 Mating systems Regular patterns of courtship amp mating within species Mating systems Regular patterns of courtship amp mating within species Monogamy Polygamy Polygyny Polyandry Promiscuity amp Polygynandry Can vary within and among populations for a species and across years Example Dunnocks may have monogamous polygynous polyandrous amp polygynandrous individuals in the same population Terminology polygyny Males may mates with many females females mate with one male per breeding season Often associated with sexual dimorphism Males look different than females Eg elephant seals defend harems of females 10X big as female Orangutan males mate with more than one female 2X big as female Polygyny is common especially among mammalsbirdsinsects Terminology polyandry Females may mates with multiple males Sexual dimorphism females sometimes have ornaments or larger Polyandry isr are in mammalsfairly rare in birds Thursday February 26 2015 Some tamarins L always twin males help care for young Jacana males help brood eggs females have nicer appearance bigger and defend territories from other females some say this term just means females mate more than once Notice different disciplines use this term in slightly different ways Terminology promiscuity Males and females both mate multiple times per breeding season no social bonds Common in insectsoccurs in many other taxa Both male and female chimps amp Barbary macaques mate repeatedly when females are in estrous Terminology polygynandry Males and females mate multiple times and maintain social bonds EgEuropean badgers have groups of parents living together Brood share multiple sires httponinelibrarywileycomdoi101111j1365294X200703571 Xabstract Terminology monogamy Males and females mate with only one partner form social bond Common in birds socially rare in insects rare in mammals lt 5 Gibbons amp siamangs coyotes amp some other canids Ornaments Often on males why pencils are on moths for emitting perfume to attract females cock on the rocks peacocks bird of paradise attractive to females Thursday February 26 2015 httpwwwyoutubecomwatchvhptrmlkk03E Elaborate ornaments Irish elk costly antlers Elaborate ornaments Peafowl lek and male s costly train The sight of a feather in a peacock39s tail whenever I gaze at it makes me sick make it harder to get away from predators Comparing males and females What makes males and females different What makes females females and males males Anisogamy Male and female gametes are different sizes Females have big gametes males have small gametes Ostrich egg vs splendid fairy wren 57M spermejaculate diff in size of gametes is extreme httpwwwsciencedirectcomsciencearticlepii80003347206004325 Consider kiwi amp eggs egg massive single gamete but animal itself is small Eggs are sometimes enormous investments per individual Not just eggs gestation care of offspring other factors Sperm is cheap relatively sometimes httpscienceblogscomtetrapodzooogy 20090220200yearsofkiwiresearch Thursday February 26 2015 Consider one egg vs many Is one giant egg so extreme What is the advantage of large gametes big egg vs small gametes tiny sperm have to make a lot of small gametes disadv but good thing is making more makes more likely to get to other sex but also they are weaker females have fewer gametes but also stronger men competing for those few eggs that s why males have more gametes Bateman principle Greater variance in male than female mating success Variance is one measure of variation SD2 result of competition Bateman principle In general this makes sense which doesn t mean it s right Females make fewer larger gametes definition of the sexes Males make many smaller gamete Should lead to competition for fertilization Sexual selection Selection on traits used in competition for mates Darwin differentiated from natural selection Ornaments hinder survival Modern evolutionary biologists view sexual selection as a component of natural selection Selection on mating success number of successful fertilizations Not selection on survival or fecundity per mate other components of selection Components may or may not be independent Thursday February 26 2015 Sexual selection lntrasexual selection within sexes Males compete for females territories and resources Males compete directly through aggression displays fights Intersexual selection between sexes Females choose among males Males compete indirectly with each other for females choice Kinds of competiton Direct malemale competition lntrasexual selection Direct Malemale Competition Direct malemale competition American elk sneak strategy little male mate with females while bigger danger male fight younger large male httpwwwyoutubecomwatchvGUQcMZLpr8 Direct malemale competition Elephant seals fight to monopolize part of beach where females are httpswwwyoutubecomwatchvDU4xW79ASsg Direct malemale competition Elephant seals A very few males get most of the copulations Most males get none Thursday February 26 2015 Kinds of competition Female mate preference or indirect male competition or Intersexual selection Bower bird Females not even choosing male traits make ornate bowers with colorful objects tend to like blue not just for good looking male female shows she is interested by walking into bower then male dances collection of blue gifts httpwwwsmithsonianchannelcomshowsdancersonfireO137551 Sage grouse And fembots like big chickens do fancy displays that get them killed by predators have motorized female bower bird to observe mating behaviors httpswwwyoutubecomwatchvmOM8pZannl httpswwwyoutubecomwatch vN3RYJWldEMM Peacock spider Notice threat of intraguild predation elaborate displays but if court the wrong species get eaten httpswwwyoutubecomwatchv9GgAbyYDFeg httpswwwyoutubecomwatch vVEAMq3y095O httpswwwyoutubecomwatchvdyYC5r8xMl Thursday February 26 2015 Notice Female preference We make no assumptions about females being conscious of decisions or about female cognition lf female behavioral differences influence what kind of male she mates with that indicates female choice or discrimination No teleology Females that mate with certain kinds of males have evolutionary advantages those preference genes spread over time We do use a verbal shorthand what does a female want