Animal Communication:
Introduction and Evolutionary History
ZOL 313
June 3, 2008
Animal Communication:
Introduction and Evolutionary History
Objectives:
1. Become familiar with different sensory modes
of animal communication and be able to
generate hypotheses and predictions.
2. Understand how sensory exploitation may
have influenced the evolution of
communication signals in animals.
ZOL 313
June 3, 2008
Communication:
Modes of
animal communication:
Visual
Auditory
Tactile
Chemical/Olfactory
Other (Electric, Sonar, etc.)
Visual Communication
Hypothesis:
Prediction:
Signalers: Fruiting plants
Receivers: Birds (blackcaps)
Visual Communication
Example:
http://news.bbc.co.uk/2/hi/science/nature/7219803.stm
Auditory Communication
Who are male birds singing to?
Hypothesis 1: Rival repulsion
Prediction:
Auditory Communication
Who are male birds singing to?
Hypothesis 2: Mate attraction
Prediction 1: Females will respond more strongly
Prediction 2: Male song will increase
Tactile Communication
Example: Social Grooming
Functions of social grooming:
Chemical/Olfactory Communication
Hypothesis:
Pheromone: a chemical that triggers a
natural behavioral response in another
member of the same species
Prediction:
Chemical/Olfactory Communication
Hypothesis: Squirrels rub snake skin
scent on themselves
Prediction:
“Other” Modes of Communication
Example: Weakly electric fish
Combination of Sensory Modes
Example: Spotted hyena greeting behavior
Why do female spotted hyenas have a psuedopenis?
Costs:
Benefits:
The Evolution of Communication
Example:
Pre-takeoff
Pelicans Gannets
Sky-pointing
Boobies
Alternate
wing-waving
Slow
wing-waving
Anhingas
Throwback
Rapid-flutter
wing-waving
Cormorants
Rapid wingwaving
Both wings waved
Wing waving
Pre takeoff
The Evolution of Communication
Example: Whistling moth males
How did they evolve ears
to hear this signal?
Ancestral State:
Saturnid moths have mechanoreceptor
cells that carry information
A whistling moth ancestor may have
had mechanoreceptor cells that gave it
Whistling moths have similar anatomy but
The Evolution of Communication
Ancestral signals can be co-opted for a new function.
Example: Whistling moth ear probably was first adaptive in detecting
Example: Some bowerbirds co-opted an aggressive signal
The Evolution of Communication
Sensory exploitation: a situation where a signaler is able to tap into a
preexisting sensitivity or bias in the perceptual system of a receiver
Example:
Female “net stance” may have evolved
first as predatory behavior (N).
The Evolution of Communication
Sensory exploitation: a situation where a signaler is able to tap into a
preexisting sensitivity or bias in the perceptual system of a receiver
Example:
Hypothesis: Female guppies originally
were attracted to orange spots
Prediction: Females with stronger
preferences for males with orange spots
The Evolution of Communication
Sensory preferences can exist in current species that have never
encountered a particular signal before.
Example: Female X. maculatus
fish
The Evolution of Communication
Sensory preferences can exist in current species that have never
encountered a particular signal before.
Hypothesis:
Prediction:
The Evolution of Communication
Sensory preferences can exist in current species that have never
encountered a particular signal before.
Zebra finches do not have
crests. Neither do their close
relatives
1. Does this experiment
support the hypothesis that
female zebra finches have a
sensory preference for a
novel signal? Why/why not?
2. From this experiment,
what color feathers (white,
red, green, or all three)
would you guess female
zebra fiches use to line their
nests and why?
The Evolution of Communication
Sensory “exploitation” does not mean responding to the signal is
maladaptive for the receiver.
For example, female that responded positively to males with an exaggerated
signal could have gained fitness for several reasons, such as:
1.
2.