Communication Intraspecific Communication Interactions between at least two

Communication Intraspecific Communication Interactions between at least two individuals signaler(s) and receiver(s) Signal often context dependent - Location - Sex - Reproductive State (Males warned, females attracted) Pough et al. 2001 Fig. 11 -14

Communication - Signaler manipulates - Receiver assesses - Reliability? Types 1 - Advertisement 2 - Courtship 3 - Aggressive 4 - Submissive 5 - Contact 6 - Alarm Pough et al. 2001 Fig. 11 -7

Communication -Modes Depends on sensory capabilities and environment Acoustic - variable, long distances, night, barriers Visual - moderate to close range, obstructable Chemical ~ adirectional, can’t readily modify Tactile - short range, may be complex

Communication Constraints 1. Small body size 2. Role of temperature Hyla versicolor- chrysoscelis Mike Redmer Pough et al. 2001 Fig. 11 -1

Communication Constraints 1. Small body size 2. Role of temperature 3. Predation - Calls - Colors - Movements Frog-eating bat (Trachops cirrhosus ), photo by Merlin D. Tuttle, Bat Conservation International.

Communication Constraints 1. Small body size 2. Role of temperature 3. Predation - Calls - Colors - Movements Anolis spp. Combat ‘Noise’ -Increase contrast -Movement -Repetition -Fill the quiet moments -Alternative Medium

Communication Major Clades 1. Chemical dominant in caecilans, salamanders, turtles, some squamates 2. Visual represented in all groups 3. Acoustic in frogs, crocs, some tortoises, geckos - associated with distance and nocturnality 4. Tactile represented in all groups - male-female courtship

Communication Salamanders ~ close range - chemical, visual, tactile - Plethodontidae and Salamandridae best studied Olfactory (volatile) and Vomeronasal (nonvolatile) Pough et al. 2001 Pheromones from head, cloaca, skin -Male with larger vomeronasal organ -Female judges male quality via feces

Communication Salamanders Courtship Male with mental glands under chin ~ enlarged premaxillary teeth rake/puncture female skin to deliver pheromone female Pough et al. 2001 Fig. 11 -10 male Pough et al. 2001 Fig. 11 -5

mental glands Pough et al. 2001 Fig. 11 -6

salamanders • • Olfactory epithelium – Vomeronasal epithelium, Pheromones produced in head and cloacal region Identify territory, mates • Mental Courtship Glands – found in males, appear during maturity and most shrink during non-breeding season – ability to deliver pheromones translates into increased mating ability by increasing female readiness and receptivity – Transferring spermatophores successfully is a difficult event – requires close coordination, therefore courtship behavior is elaborate

Anurans 1) Chemical signals 2) Visual cues – Foot-flagging display of Hyla parviceps

• Acoustic signals primary mode of communication • each species has distinct vocalization & individuals produce variety of calls • Most males have vocal sacs for sound resonation

Communication Anurans Little chemical, some visual, much VOCAL Males with calling adaptations: - vocal sacs - aerobic trunk musculature - frequency, amplitude, pulse rate (clicks, tones, whistles, squawks, trills etc. ) Pough et al. 2001 Fig. 11 -15

Communication Anurans Advertisement calls 1. Attract mates 2. Signal territoriality Males Assess (volume, call characteristics) 1. Distance 2. Individual Neighbors Females Assess (frequency, amplitude, pulse rate) 1. Species 2. Size 3. Fitness

Communication Anurans Detection: - Tympanum - Body-wall and lungs via Eustachian tubes - two sensory organs in ear 1. Basilar papilla (high frequency) 2. Amphibian papilla (low frequency) Species and Sex differences in ‘tuning’ of ear Courtship Calls close range; male and female Aggressive Calls often louder and faster Release Calls Startle Calls

Pough et al. 2001 Individual Nerve Fibers from: R. Basilar papilla (high frequency) L. Amphibian papilla (low frequency)

http: //www. uga. edu/srelherp/anurans/index. htm http: //animaldiversity. ummz. umich. edu/site/topics/frog. Calls. html

1) Components of anuran vocalizations: • Call = the entire assemblage of acoustic signals produced in a given sequence • Call rate = frequency of production of calls • Note = given individual unit of sound • Pulse = emphasized energetic impulses in the temporal spectrum of a note (inaudible to the human ear) • Spectral frequency =

2. Call types: 1. advertisement (attraction of gravid females) 2. reciprocation 3. release 3. distress

3. Ear Structure: Anurans have a distinct middle ear w/ a tympanic membrane. Airborne sound waves are transmitted via the tympanum and columella to the inner ear, where mobilization of the perylimph is coupled with the endolymph to create motion of the motion on the receptor cells of the papilla amphibiorum and papilla basilaris. The sensory receptors in the inner ear are also highly sensitive to seismic vibrations.

Communication Turtles Male courtship of Females best studied 1. Sniff 2 a. Bite at shell, head, legs 2 b. Display colored neck and legs 2 c. Stroke female’s head with legs or head photo by Roger A. Repp Tortoises (Testudinidae) visual, tactile, chemical, vocal plastron used to ram males and females Gopherus chin gland secretions head bobbing, forelimb wiping Pough et al. 2001

Turtle communication 1) Olfactory cues: male “sniffs” females cloaca to id species/sex Chelonia mydas (green sea turtle)

2). Tactile cues used:

Behavior that occurs between 2 male desert tortoises. When males interact w/females, the sequence begins the same way but when the female retreats instead of producing headbobs in response to the male’s headbobs – the male continues to approach, intensifies his headbobbing and then circles the male… he will then bite or ram her and then mount her. . . Often scratching her shell -

Communication Crocodilians Most vocal reptiles Combine acoustic, visual, tactile into complex displays Bellowing (advertisement) audible (M and F) and subaudible (M) Head slapping (advertisement, aggression) includes jaw snap, body posture, growling Female initiates courtship head and snout rubbing, blowing bubbles Juveniles communicate with each other and with parents

Crocs 1) Vocalization 2) Tactile & Visual

Acoustic signals include grunts & slapping sounds – In alligators, males and females bellow & loud, low frequency bellows are only produced during the mating season. Close range communication includes cough-like calls.

Communication Lepidosaurs Tuatara similar to Iguanian Squamates Visual - Color (and color change) head movement body inflation gaping dorsal crests Anolis spp. Territoriality Mate Attraction Species specific patterns of movement and color Femoral gland secretions

Lizards 1) Visual & tactile – Iguanids Dewlap of Anolis displayed along w/head bobs-

Komodo dragons tongue-flick females 2) Olfactory Scleroglossans

Communication Lepidosaurs Scleroglossans Pough et al. 2001 Rely more on chemosensory communication - Tongue Flicking

Communication Lepidosaurs Gekkonidae Most vocal group Unique among lizards in having vocal cords Serpentes -Chemosensory (and tactile) - limited visual - lack external ears and don’t use acoustic mode Males follow females Skin Pheromones Directional tongue Copulatory Plug Wrestling Crotalus exsul (ruber)

snakes 1) Olfactory 2) Tactile

Tactile-chase phase: Male places his body next to the female, looping over her + he rubs his chin on her back and may bite her Tactile-alignment phase: First attempts to copulate Caudal vibrating movements used to properly align cloaca Intromission and Coitus: insert 1 hemipenis