Transcript Lecture 5 Communication

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
•
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•
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/frogCalls.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
2a. Bite at shell, head, legs
2b. Display colored neck and legs
2c. 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 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