Presentation on theme: "1 Visual Mimicry. 2 Objectives Explain why animals use mimicry Describe some of the categories of mimicry Describe the three participants of mimicry Explain."— Presentation transcript:
2 Objectives Explain why animals use mimicry Describe some of the categories of mimicry Describe the three participants of mimicry Explain aposematic and give examples Understand the difference between aggressive, sexual, mutualistic, and protective mimicry Describe an example of audio mimicry Why do animals use eye mimicry Explain how imperfect mimicry is still successful Describe the speed versus accuracy relationship in mimicry Provide an example of human mimicry
4 What is Visual Mimicry? 3 Players –The Model Produces stimuli –The Mimic Copies the model –The Dupe Deceived by the mimic
5 How do we categorize visual mimicry? Aggressive Mimicry –Allows mimic to avoid detection by prey Reproductive Mimicry –Mimic propagates its own species Mutualistic Mimicry –Mimic and dupe help each other Protective Mimicry –Avoids detection by threat
6 Aposematic A “warning” signal: –Color –Sound –Smell Advertising to a predator to avoid because: –Unpalatable taste –Poison / Toxin –Noxious Odor
9 Cookie-cutter Shark Bioluminescent shark Photophores on bottom (ventral side) –Mimics the ambient light in dim, deep oceans Counter-illumination –“Dog collar” band lacks photophores = mimics a small silhouette to predators below –As predator investigates the silhouette, the shark bites out plugs of flesh from the swimming predator hence the name “cookie-cutter” –Watch this video: http://www.youtube.com/watch?v=syISlRJTaw4> http://www.youtube.com/watch?v=syISlRJTaw4 (Widder, 1998)
10 Deep-sea Anglerfish Family Ceratiidae Fishing Pole –Dorsal spine –Only females –Luminous tip ‘mimics’ small animal movement to lure prey –Large mouths quickly consume prey –Video: http://www.youtube.com/watch ?v=RitJe16c3sM http://tolweb.org/Ceratiidae/22010
Reproductive mimicry “Duping the mate or donator” 11
12 Duped Pollinators Some plants attract pollinators of other plants using color –Epidendrum ibaguense, flower has no nectar, but ‘dupes’ the pollinators of other flowers Lantana camara Asclepias curassavica –Some orchids ‘dupe’ the lamellicorn beetle –The beetle mistakes flowers for similarly colored Cistus flowers Epidendrum ibaguense http://www.sbs.utexas.edu/quedensley/epidendrum %20radicans%20TQ-4904-1.JPG http://www.sbs.utexas.edu/quedensley/epidendrum %20radicans%20TQ-4904-1.JPG http://www.sbs.utexas.edu/quedensley/epidendrum %20radicans%20TQ-4904-1.JPG
13 Giant Australian Cuttlefish Male cuttlefish ‘sneaks’ to mate A: Unpaired male (m) assumes female coloration and posture and approaches the paired female (f); the consort male (c) displays to an approaching male (top right); conspicuous –Consort and approaching male have large white arms, a sexually dimorphic male character B: female accepts a mating attempt by the female mimic as the consort continues to repel the other male C: the consort allows the mimic to finish mating, even when he is not distracted by an approaching male
14 Spotted Hyenas Sexual organs mimic the male reproductive organs –Female cubs more at risk from aggression than male cubs. –Aggressors should have difficulty distinguishing the sex of their potential victims –Sexual mimicry is the greatest during the period of highest risk.
16 Orange and Black Coloration Mullerian mimicry Two unpalatable species evolve a similar appearance –Reduces predation mortality by training predators to avoid –Orange and black coloration: lycid beetles, arctiid moths, parasitic hymenoptera, and flies –Predators avoid two distinct unpalatable prey at similar rate, Two unpalatable species, (a) lycid beetle (Coleoptera), (b) arctiid moth (Lepidoptera) with mutualisitc mimicry (Sherratt, 2008).
Mutualistic mimicry in Peruvian Dendrobate Frogs http://www.ucl.ac.uk/taxome/jim/Mim2/dendrobates.html
19 Decorator Crab Wears its environment Found near Australian coastline –Spider crab family –Small hooks to attach algae and seaweed –Uses oral secretion to bind camouflage to hooks –The algae continues to grow The decorator crab covered with algae and seaweed (http://farm3.static.flickr.com/2007/2256514518_2e71f0c6c8. jpg?v=0) http://farm3.static.flickr.com/2007/2256514518_2e71f0c6c8. jpg?v=0http://farm3.static.flickr.com/2007/2256514518_2e71f0c6c8. jpg?v=0
20 Mimic Octopus Thaumoctopus mimicus Found in Indonesian Archipelago Can impersonate several different animals –Flatfish/Flounder –Lion-fish –Sea-snake –Sea anemone –Jellyfish (Norman et al., 2001).
22 Audio Mimicry? Tiger Moths h unted by bats at night Use an audio aposematic signal Answer the bat echolocation with high-frequency 'clicks' from vibrating membranes (tymbals) on the bottom-side portion of the thorax. Bats avoided the moths when the sounds were paired with defensive chemistry. –No jamming –Acted as audio warning Various Tiger moths with/without a chemical defense (C+ or C-) and with/without a sound strategy (S+ or S-) (Hristov and Conner, 2005).
Eye Mimicry Confuse a predator Allow enough time for escape
Imperfect Mimics succeed? Some mimics are successful, even though they only generally look like a model Possible explanations: –mimic has not converged fully on the model –Models and mimics engaged in evolutionary arms Model under pressure to evolve away from the mimic –Degree of similarity related to frequency of mimic and model –Conflicting energy demands on color patterns Compromises between signaling and constraints of thermoregulation
Hoverfly Loosely resembles common European bees and wasps A-B = wasp C-F = imperfect mimics (Chittka and Osorio, 2007)
Fly A-C = Bees D = Fly The fly generally has bee- like: –Body –Morphology –Integuments –Stripes
Predator Speed versus Accuracy Predators must make a decision on prey either: –Quickly pick the prey –Accurately discriminate between palatable and unpalatable A quick decision may allow imperfect mimics enough time to escape Categorization of prey –Very different prey share common character(s) –Different predators may form different categories Lab-raised birds attack bees, wasps, and mimics –Learn to reject them all once they consume an unpalatable prey
Human mimicry? http://www.airforce.mysteria.cz/foto/F117/F117-1.jpg http://kelticklankirk.com/Special_Forces_Horse_Cavalry_ Afghanistan_01.jpg http://www.flickr.com/photos/gara_blacklone/3200563890/ http://cache.lifehacker.com/images/2006/05/identity-theft.png
32 Summary Why do animals use mimicry? What are the four general categories of mimicry? What are the three participants of a mimicry system? What does aposematic mean? Provide examples. Describe aggressive mimicry. Describe sexual mimicry. Describe mutualistic mimicry. Describe protective mimicry Can animals use audio mimicry? Why are animals that use imperfect mimicry still successful? What is the relationship between the speed and accuracy of a predator’s cognitive ability and mimicry? Can humans use mimicry? How?