Multi-Modal Courtship in the Peacock Spider,
Maratus volans (O.P.-Cambridge, 1874)
Girard et al. 2011
Dynamic Osheanic DuoRashelli Linz & Kristiana Heath
Journal
● PLOS ONE
○ Public Library of Science
○ Peer- Reviewed Open
Access Journal
○ 15th Anniversary
○ Impact Factor: 3.24
Authors
Madeline B. Girard
Michael M. Kasumovic
Damian O. Elias
2007 Ph.D Evolutionary Biology at University of
Toronto
2005 Ph.D Neurobiology and Behavior at
Cornell University
2017 Ph.D at U.C. Berkeley
Field Biologist- behavior, ecology and
evolution
Masters in Counseling Psychology
Presently a Associate Marriage & Family
Therapist and Psychedelic Psychotherapist
H Index: ?
Studies involve animal behaviors (including
humans)
Studies Neuroethology, behavioral ecology, and
evolutionary biology of arthropods
Associate Professor and Future Fellow at
University of New South Wales
Associate Professor at U.C. Berkeley
H Index: 28
H Index: 34
Trivia
Big Questions
● Do species-specific mating displays exist for this species?
● Are Peacock Spiders’ Courtships Multi-modal?
● What is the evolutionary and functional significance of
complex displays?
Specific Questions, hypothesis, predictions
Specific Question: Which signals are used in Peacock Spiders’
Courtships?
Hypothesis: The repertoire of Maratus volans courtship
behaviors includes complex visual displays and vibrational
signals
Prediction: Expected to find multi- modal courtship behaviors;
males of many species produce multi-component signals
Methods
Methods
Methods
Methods
Results
●
Total courtship time: 6-51 min
●
Use of visual and vibrational patterns varied, but common sequence
framework present
●
Certain behaviors consistently identified
Results
Visual Displays
1.
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Pedipalp Flicker
Occurred intermittently throughout entire
duration of courtship
Alone or in conjunction with all other
displays
Performed by both sexes
Also occurred outside of courtship (feeding,
moving while alone)
Increased in intensity preceding movements
like opisthosomal bobbing and leg waving
Results
Visual Displays
2.
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●
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Opisthosomal Bobbing
Move abdomen up and down
independently of
expansion/retraction of
opisthosomal flaps
Associated with vibrational signals
Lateral abdomen movements
sometimes occurred between bobs
Results
Visual Displays
3.
3rd Leg Wave
● Majority of courtship display
● 3rd legs elongated and
ornamented
● Often precedes fan expansion
● Usually bilateral, but
occasionally independent
● Often occur in conjunction with
side-stepping
○
Male moves in semi-circles around
female
Results
Visual Displays
4.
Fan Dance
● Most notable sequence
● Each fan movement cycle
corresponds to single 3rd leg
wave (c-e)
● Closer to female- male
hunkers down
○ Lowered carapace
○ Front legs bent more
sharply
○ 3rd legs erect in V
position
Results
Visual Displays
5.
Fan Flapping
● Pause after 3rd leg waving bout
○ Gauge female attention?
● Slow flutter of opisthosomal fan
○ Female was observed reorienting towards male
○ Occurred until female model swiveled towards male
Results
Visual Displays
6.
Pre-mount Display
Proceeds in precise sequence:
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●
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3rd legs rotate to front of carapace
Opisthosomal flaps retracted,
abdomen tilted until level with
carapace
Regularly spaced opisthosomal
bobbing
Tremors of 3rd legs, rapid up-down
3rd leg movement
After 3-8 tremors- 1st legs raised off
substrate and 3rd legs extend to
upside-down V (glider pose)
Male moves towards female with
each bobbing bout
Results
Vibrational Signals
● Utilized throughout courtship
● Often a precursor to motion displays
○ Female at distance or not oriented
● Caused by abdomen oscillation
Results
Vibrational Signals
● All coincide with opisthosomal
bobbing
● Mechanism unclear:
○ Stridulation (rubbing together) of
paired abdomen or
cephalothorax structures
○ Tremulation- abdominal
oscillations transferred directly to
substrate via legs
Results
Vibrational Signals
Two Categories:
● Occur immediately, continue intermittently
○ Rumble-rumps (Rb-Ru)
● Pre-mount display only
○ Crunch-rolls (Cr-Roll)
○ Grind-revs (Gr-rev)
Results
Vibrational Signals
1.
Rumble-rumps (Rb-Ru)
● Most common
● Occur as soon as male senses female
○ Continue between leg-waving and fan-dancing
○ Stop before pre-mount display
Results
Vibrational Signals
1.
Rumble-rumps (Rb-Ru)
● Short duration
● Corresponds to
opisthosomal bobbing
● 2 distinct elements
○ 1x Rb
■ Composed of
3-8 bumps (b)
○ 1-5x Ru
Results
Vibrational Signals
2a.
Crunch-Rolls (Cr-Roll)
● Preceded by intro signal
● Occur as soon as male senses
female
○ Continue between
leg-waving and
fan-dancing
○ Stop before pre-mount
display
Results
Vibrational Signals
2a. Crunch-Rolls
(Cr-Roll)
● Consist of:
○ Swish (Sw)
○ Crunch (Cr)
○ Roll (Roll)
■ 3-7
smaller
elements
(r)
○ Tail (Tail)
Results
Vibrational Signals
2b.
Grind-rev (Gr-rev)
● Final stages of pre-mount thru
attempted copulation
● Coordinated with leg movement
○ Glider pose
● Advances towards female with
each Gr-rev
●
Results
Vibrational Signals
2b. Grind-rev (Gr-rev)
● 12-34x per bout
○ Composed of series of grinds (g) in groups of 3-11
○ Become increasingly blurred at end of pre-mount display
Results
Was the hypothesis supported by the results?
Hypothesis: The repertoire of Maratus volans
courtship behaviors includes complex visual
displays and vibrational signals
Both visual displays and vibrational signals
were observed and categorized.
Conclusions and Support
●
Maratus use both visual and vibrational components in mostly predictable
patterns in courtship behavior
○
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Supported: both components observed in a generally predictable order
Courtship displays vary between individuals and environmental situations
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Somewhat supported: variations observed, but further study required
Novel contribution, Advanced the field?
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First in-depth description of Maratus courtship displays
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Establishes framework for future research within the genus
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Allows for comparisons of multi-modal signaling across related genera
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Aids in understanding of the evolution of signaling modality preference and
the role that female choice plays
Why would we cite this paper?
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Novelty- in-depth descriptions of courtship display elements and progression
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Framework for future studies on Maratus spiders
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Results can be used to compare genera
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Provides important points in the discussion of multi-modal signaling, female
choice, and evolution of signaling systems
Thank you!
Questions?