ANIMAL COMMUNICATION III. CONTEXT A. PARENT OFFSPRING BEGGING IN CHICKS

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1 I. DEFINED -PROVISION OF INFORMATION BY A SENDER TO A RECEIVER, AND THE SUBSEQUENT USE OF THAT INFORMATION BY THE RECEIVER IN DECIDING HOW TO RESPOND. SIGNAL: VEHICLE OF INFORMATION 1) MUST PROVIDE (POTENTIAL) BENEFIT TO SENDER AND THE RECEIVER A. PARENT OFFSPRING BEGGING IN CHICKS -BEGGING SIGNALS HUNGER STATE (SIGNAL CONTENT) -MORE ACTIVE (LOUD AND FREQUENT) GETS MORE FOOD TEST: FLYCATCHERS BY OTTOSON ET AL. 87 -SO, AN OWL HEARING A MOUSE MOVE AND USING THIS SOUND TO LOCALIZE IT IS NOT -SOUND MOVEMENT: CUE, NOT SIGNAL -OWL HEARING: EAVESDROPPING, NOT COMMUNICATING II. SIGNAL COMPONENTS: SIGNAL CONTENT WHAT DOES THE SIGNAL CONVEY? SIGNAL DESIGN HOW IS THE SIGNAL DESIGNED TO BEST CONVEY THE CONTENT TO THE RECEIVER - SUBJECT TO SELECTION OF THE ENVIRONMENT AND OF THE RECEIVER BIASES -MALE OR FEMALE FITTED WITH CHIP THAT ACTIVATES RECORDING OF BEGGING UPON APPROACH -PARENT WITH CHIP FED THE CHICKS MORE OFTEN THAN PARENTS WITHOUT CHIPS -SUGGESTS THAT BEGGING COMMUNICATES HUNGER STATUS OF CHICK A. PARENT OFFSPRING DISTRESS AND HELP CALL IN CROCODILES - EGGS ARE LAID IN NESTS THAT HARDEN 1. UPON HATCHING, YOUNG CROCODILE CALL FOR HELP TO BREAK FREE 2. WHEN THREATEND, YOUNG CROCODILES CALL FOR HELP B. GROUP : RECOGNITION OF KIN IN A LARGE GROUP e.g., RHESUS MACAQUES BY RENDALL ET AL. 96 -LIVE IN GROUPS -CAN INDIVIDUALS RECOGNIZE KIN BASED ON VOCALIZATIONS CONTACT CALLS -RECORDED AND PLAYED BACK RECORDINGS TO SEE RESPONSE -SIGNIFICANTLY RESPONDED TO KIN: QUICKER AND LONGER -SUGGESTS THAT CALL IS FOR RECOGNITION

2 C. PREY TO PREDATOR B. DOMINANCE: AVOID CONFLICT -FIGHTS CAN BE VERY COSTLY, SO ANIMALS SHOULD EVOLVE SIGNALS TO AVOID PHYSICAL FIGHTS SIGNALS! 1. GAZELLLE STOTTING REDUCES LIKELIHOOD OF CHASE & CAPTURE SIGNAL OF GAZELLE CONDITION? BY FITZPATRICK AND FANSHAWE SIGNAL INDIVIDUAL CONDITION C. PREY TO PREDATOR 2. UNPALATIBILITY OR TOXICITY POISON-DART FROGS (DONDROBATIDS) IV. MODES OF IN VERTEBRATES A. VISUAL: BASED ON COLOR AND BLACK & WHITE CONTRASTS B. SMELL: BASED ON CHEMICALS (OLFACTORY SIGNALS) C. SOUND: BASED ON DISTURBANCES OF A MEDIUM LIKE AIR OR WATER (AUDITORY) D. TOUCH: BASED ON STIMULATING SENSORS ON THE SKIN (TACTILE) E. ELECTRICAL: BASED ON CHANGING OF ELECTRICAL FIELDS Both groups have batrachotoxins, neurotoxins that cause paralysis.

3 Trinidad Guppy (Poecilia reticulata) dimorphic males smaller and colorful, females drab and larger native to Trinidad &Venezuela clown fish, Amphiprion ocellaris Paracheirodon axelrodi (red neon tetra) females prefer colorful males electric fish mate choice by electric fish: fish that can perceive and create an electric field Can generate100v to stun prey Primarily used like a radar but also used in communication, especially mate choice

4 V. GENERAL OVERVIEW IN VERTEBRATES: PREDOMINANT MODES OF olfactory (chemical) signaling in minnows and pikes 2. AMPHIBIANS: VISUAL, AUDITORY AND OLFACTORY VISUAL Poison dart frogs FLATHEAD MINNOW BY CHIVERS AND COLLEAGUES -WHEN MINNOW IS TAKEN BY PIKE, RELEASES CHEMICAL CUES -ATTRACTS OTHER PIKE AND INCREASES HANDLING TIME SOMETIMES ALLOW FOR ESCAPE (5 OF 13 IN THE EXPERIMENT DID) two color forms of Dendrobates pumilo in Panama Preference for own Color 2. AMPHIBIANS: VISUAL, AUDITORY AND OLFACTORY AUDITORY -males call out in Spring -females prefer (approach) long calls 2. AMPHIBIANS: VISUAL, AUDITORY AND OLFACTORY AUDITORY AND VISUAL ARE NECESSARY! e.g., Poison Dart Frog by Narins and colleagues Is call and visible vocal sac necessary? -just calls, no fake frog: approach, no aggression -calls with various visual signals: see graph *Need both sound and pulsating vocal sac to initiate aggression

5 2. AMPHIBIANS: VISUAL AND OLFACTORY OLFACTORY SALAMANDER Many salamanders use chemical secretion to mark territories and to attract mates 3. REPTILES: VISUAL AND OLFACTORY VISUAL ANOLIS DEWLAP PUSH UP DISPLAYS FENCE LIZARDS AND AUSTRALIAN AGAMIDS e.g., California Slender Salamander -tested with moss with own chemicals vs. foreign -more aggressive (ATR trunk raised) and retreat behavior when smelling foreign chemical THREAT DISPLAYS ARE USED TO DEFEND TERRITORIES V. GENERAL OVERVIEW IN VERTEBRATES: PREDOMINANT MODES OF 3. REPTILES: VISUAL AND OLFACTORY 4. BIRDS: VISUAL AND AUDITORY OLFACTORY MARSHALL LIZARD e.g. Lacerta monticola lizard by Martin and Lopez

6 4. BIRDS: VISUAL ANDAUDITORY 4. BIRDS: VISUAL AND AUDITORY AUDITORY Song Sparrow VISUAL SIGNALS VOGELKOP BOWERBIRDS 4. BIRDS: VISUAL ANDAUDITORY usually both, in a complex courtship e.g., White-collared manakins in Central America - complex dance, which involves rapid flight between samplings near ground - extension of elaborate and bright plumage - vocalizations (grunts) - snapping of wing feathers 5. MAMMALS: VISUAL, OLFACTORY AND AUDITORY (ALSO TOUCH) -BODY SIZE -WEAPON SIZE -PHYSICAL BATTLES

7 5. MAMMALS: VISUAL, OLFACTORY AND AUDITORY e.g., fallow deer by Clutton-Brock and colleagues -males aggregate in leks to attract females -groan rate correlates with mating success V. GENERAL OVERVIEW IN VERTEBRATES: PREDOMINANT MODES OF 5. MAMMALS: VISUAL, OLFACTORY AND AUDITORY e.g., olfactory Humans and MHC experiment men wore shirt for two nights in a row, and women were blindfolded and allowed to sniff shirts. Choose most attractive smell and relate this to MHC alleles results 1: women not taking oral contraceptives: found disimilar males more attractive than similar males women taking contraceptives: found similar males more attractive than dissimilar males results 2: odors of MHC-dissimilar men reminded women of their ex- or current partners more often than MCH-similar males frequency V. GENERAL OVERVIEW IN VERTEBRATES: PREDOMINANT MODES OF 5. MAMMALS: VISUAL, OLFACTORY AND AUDITORY (ALSO TOUCH) e.g., all four in wolves VI. SIGNAL DESIGN HOW DO SIGNALS EVOLVE? A. BASED ON ECOLOGICAL FACTORS e.g., VISUAL SIGNALS Phylloscopus warblers of India howling: long-distance signaling to pack growling: aggressive whimpering: submissive aggressive: teeth exposed, ears and hair erect urine and chemicals from scent glands communicate territory wolves reciprocally groom pack mates social bonds -ANIMAL SIGNALS HAVE TO CONTRAST THE ENVIRONMENT (NOISE) AND BE CONSPICUOUS -ENVIRONMENT SHOULD SELECT FOR SPECIFIC SIGNALS THAT BEST FIT THAT ENVIRONMENT (PART OF PROCESS CALLED SENSORY DRIVE) -e.g., IN DARK HABITATS, MORE BRIGHT PATCHES THAN OPEN HABITATS

8 VI. SIGNAL DESIGN HOW DO SIGNALS EVOLVE? A. BASED ON ECOLOGICAL FACTORS Karen Marchetti (UCSD) on Phylloscopus warblers of India VI. SIGNAL DESIGN HOW DO SIGNALS EVOLVE? B. BASED ON RECEIVER PHYSIOLOGY e.g., Rodd and colleagues work on guppies -Females prefer orange males -But different populations have different degree of preference for orange and amount of orange in males -guppies feed on orange fruits that fall to the rivers -tested several different food types, most populations preferred orange food -extent of preference for orange related to extent of preference for orange males! Number of Bright Patches Correlate with Lighting Conditions