Chapter 6 Flashcards
Deborah + Ted Talk
- ants interact w/ anntea - identify other ants
- rate at which ants meet other ants – proudce network
- Desert - operatin cost - high - water is scare - spend water to get water
-Variation - some colonies forage less on dry days
-ants as neurons -> ant adds up stimulation from other ants to decide whter to forage or not
How many interaction does an ant need to go out and forage?
Colony 154
Data doesn’t leave source computer unless theres enough bandwidth
operating cost loe - tropics - adunant / diverse ants - lots of competition
Ant secuity - pkugging enterance w/ head - until threat passes
Expandable search networks - many ants small sp[ace - search thoughly - opp, way too
clustered resource - use them for recruitment - trail of ants
Odour of Waggle Dance Bees
Waggle dance indicates distance and direction to food source
Observation: most recruits take longer than expected to find food source
Bees + Research Question
Research Question: Do bees also use odor to find the food? (Riley et al. 2005)
Bees + Methods
- Placed food at feeding station 200 m due east of hive
- Recorded wind speed and direction
- Marked bees with transponders
- Released bees at one of three locations
- Measured movement of bees
-Food had no odour
-place flight paths moved through a clear plastic tube to enter leave hive – mark bees w/ small tags
Bees + Results
Most bees released at hive and displaced bees flew east (toward food station direction)
Only 2 of 19 recruits found the food station
After 200 m, most individuals began circuitous flight path
Wind data indicated no odor from feeding station available to bees
Bees + Conclusion
Waggle dance does signal distance and direction of food
Bees need additional cues (odor) to find exact food location
Monkeys + Alarm Calls
Monkeys have specific calls for predators
Alarm Calls
– unique vocalization produced by social animals when a predator is nearby 66
chemical signals
readily travel thro water/air ,long lasting+great distance, contorl strength, travel around envirnomental barriers, can be deposited as substrate
Visual Signals
requires suff. ambient light levels - blocked by obstacles
Auditory signals
can bypass obstacles, produced at diff amplitudes
Ants + Chemical signals
Temperature of surface should affect the duration of signal
- quantified the activity of free-living colonies - count # of workers on feeding trails b/w food source + nest
- recorded surface temperature @ colony entrance
lab trained coloines - fed honey + water - cross brdige and heated to several diff temps - food is at other end of the bridge
Ants + Chemical signals
Temperature of surface should affect the duration of signal
- quantified the activity of free-living colonies - count # of workers on feeding trails b/w food source + nest
- recorded surface temperature @ colony entrance
lab trained coloines - fed honey + water - cross brdige and heated to several diff temps - food is at other end of the bridge
Ants + Chemical Signals Results
-high surface temps - chemical pheromone signals are ineffective comm. mode - affects effectiveness of chemical pheromones
Light + Fish Visual Signals
-favours signals with strong contrast
- females are grey - males are blue / all yellow - use this during courtship
- court in 2 distinct habitats - shallow beach sites + deep water sites w/ algae
- Does male morph colour affect reproductive success differently in each habitat as predicted?
- Mating: 1) Mating displays 2) Sneaker males
Light + Fish Visual Signals Results
- Highest reproductive success - males who had a strong contrast w/ background
- blue > yellow - beach, yellow> blue - shallow
Auditory + Satin Songbirds
- stand out from environment
- travel long distances - lose quality + intensity over time - degrade + attenuate
- rate = affected by habitat structure - Prediction: variation in calls is due to vegetation structures across populations
Auditory + Satin Songbirds Methods
- Recorded male advertisement calls from various location - vary in habitat + vege. struc.
- measured using sonograms to charactize avg. calls - frequency, call durations etc.
- Characterize vegetation - # of tree stems + width
Auditory + Satin Songbirds Results
calls varies across sites- habitat type
min + dominant freq - lower in sites w/ more trees
Evolution of signals
depends on the signallers and receivers - 2 diff interests - can create 2 different outcomes
1) signal evolves to be acc indicator of of signaler phenotype / environment
2) signal evolve to be inacc indicator of conditions
Titmouse Alarm Calls Observation + Research Question
Tufted titmice produce alarm calls
Vocalization can be visualized in sonogram
Research question:
Do alarm calls of titmice differ with the size and degree of threat of a predator?
Size of predator negatively correlates with risk of titmouse
TTM + Methods
Placed model 1m from feeding station mice were in 25 m of feeding target, “predator” was uncovered - small + high risk / large+low risk
Recorded titmice behaviour and alarm calls
Control: Empty platform
Mobbing behaviour
when there is predator – birds fly by predator in large numbers
Titmice + Results
Produce more D notes in alarm calls during high-risk predator treatments
More mobbing behavior during high-risk treatments with small raptors
Titmice + Conclusion
Titmice produce different alarm calls that lead to different behaviors
Sensory receptors
Nerve endings that respond to an internal or external environmental stimulus
Chemoreceptors
They detect chemical stimuli
- Chemoreception includes olfaction and gustation
- There are two classes of chemical stimuli: odorants and pheromones
Gustation + Olfaction
G: detection chemical stimuli
O: Sense of smell
Pheromones
Volatile (gaseous) compounds that are species-specific and affect the behaviour of another individual of the same species + interpreted by sense of smell
Bruce Effect
Disruption in implantation due to presence of a novel male
MALE THAT FEMALE NEVER MET – COMES IN EINVROME
EGG GETS FERTILS TO SPERM – FETILZIED – MALE COMES ALONG – IMPLANATION IS DISRUPTED
Vandenbergh Effect
Decrease in time to sexual maturity due to presence of a novel male
female reaches sexual maturity sooner
Bruce Effect + hormones
17β-estradiol & testosterone in male urine (Muir et al., 2001)
Castrated males lose ability to disrupt pregnancy, unless given 17β-estradiol
Females given 17β-estradiol antibodies retain their pregnancy
When aromatase (enzyme that helps w/ production of estradiol) inhibitor is administered to an intact male, lose ability to disrupt pregnancy
Vadenbergh Effect: Indirect Exposure Paradigm
males _ females – be as distinct / genetically diff as possible
Males house on top of females
VE + Results
Y axis – estradiol levels
Males exposed to developing females = higher estradiol compared to isolated males
Males exposed to developing females had higher output of testosterone in urine
Mass difference – sexual difference – males have the effect – pheromones have non-volatile chemicals – testos. + estradiol
Condtions that favour the evolution of signals as accurate
- Fitness interests of signaler and receiver are similar
- Signals will be accurate when they cannot be faked
- Signals will be accurate indicators when they are costly to produce or maintain
Aposematic Colouration
bright colour morphology in species – stand out from environment + assoc. w/ chemicals / poisons
Prey – bight colour
Prey + predator – similar interest – done eat me, I don’t want to eat you
( 1. Fitness interests of signaler and receiver are similar.
Fitness interests of predator and prey are similar)
Aposematic Colouration + RQ
Why are dendrobatid frogs brightly colored?
Frogs + hypothesis + predic
The bright reddish-orange body colour with blue appendages is an aposematic signal
Frogs with bright reddish-orange body colour attacked less often than brown-colored frogs
Frogs + Models
Created models of:
Dendrobatid frog (Oophaga pumilio)
Brown leaf-litter frogs from genus Craugastor that do not contain poisons
- Placed 800 frog models on forest floor or white paper
- After 48 hours collected models and recorded predation attempts
Frogs Results + Colouration
Over 12% of models attacked
Brown models attacked twice as often as brightly colored models
Conclusion:
Bright colouration is an aposematic signal to predators that prey are unpalatable
**Brown – could also camouflage – also some an advantage – why all animals are not bright
male wolf spiders + Research Question + Hypothesis (1)
a. Do male wolf spider leg raises provide an accurate signal to females?
b. Good-condition males will display at a higher rate than poor-condition males.
(Signals will be accurate when they cannot be faked - only large males produce low vocalizations)
male wolf spiders + methods (1)
Collected 60 juvenile male and 60 juvenile female spiders and raised them in the lab for three weeks. Poor-condition treatment (PC) spiders were fed one cricket twice per week. Good-condition treatment (GC) spiders were fed four crickets twice per week.
- Measured male courtship rate in a cylindrical arena * Repeated the trial for the next three days using the same individuals to test for consistency
Male wolf spiders + results (1)
GC males displayed at higher rates than PC males. - prob more hunrgy
Display rate was consistent across the sample, except for GC males mated to PC females.
Male wolf spiders + Conclusion (1)
Mate condition affects male courtship display rate and is an accurate signal of male quality and fitness.
male wolf spiders + Research Question + Hypothesis (2)
High display rate in males indicates high quality.
b. Females mated to males with high leg display rates will have higher reproductive success.
male wolf spiders + methods (2)
): Mated females with males in two groups:
(1) Males with high leg display rates (5.9 leg raises/min)
(2) Males with low leg display rates (3.0 leg raises/min)
Measured the number of spiderlings and their survival
Male wolf spiders + results (2)
Females mated to males with a high display rate had more spiderlings and higher offspring survival than females mated to males with a low display rate
Male wolf spiders + conclusion
Mate condition affects male courtship display rate and is an accurate signal of male quality and fitness
Signals are be inaccurate when
When the Fitness interests of Signaler & Receiver Differ
Co-evolutionary arms race
Co-evolutionary arms race
Signalers are selected to produce signals that affect the behaviour of receivers, and receivers are selected for better discrimination abilities
Mimicry
Adaptive resemblance of one species (the mimic) to another (the model
Bastesian Mimicry
The resemblance of
a palatable mimic to an unpalatable
model that predators have learned to
avoid.
Salamander Mimicry + ober + RQ + Hypoth
Observation: Palatable yellow-eyed, Ensatina, salamander resembles a toxic newt
Research question: Is the yellow-eyed salamander a Batesian mimic? (Kuchta, Krakauer, & Sinervo 2008)
Hypothesis: The yellow-eyed salamander is a mimic of aposematic newts in the genus Taricha
Salamander + Methods
different days had different feeding patterns
Salamander + results
Seven of ten jays did not touch toxic model
All birds contacted palatable Ensatina subspecies more quickly than yellow-eyed salamander
Salamander + Results
Yellow-eyed salamanders effectively mimics toxic newt and so is a Batesian mimic
Aggressive Mimicry
The bright leaves of the venus flytrap (Dionaea muscipula) attract insects in the same way as flowers.
The Spotted Predatory Katydid (Chlorobalius leucoviridis) is an acoustic aggressive mimic of cicadas
Bystanders / eavesdroppers
A third-party individual that detects a signal transmitted between a signaler and a receiver
Audience Effect
Occurs when the presence of bystanders influences the behaviour of a signaler
Audience effects in fighting fish + obser + RQ (2)
Observation: Male fighting fish are highly aggressive and compete for territories and mates.
Research question (1): How does the sex of the audience affect male display behaviour?
Research question (2): How does familiarity with an opponent influence male display behaviour?
Audience effects in fighting fish + Methods
Examined aggressive behaviour of focal male as it interacted with familiar or unfamiliar opponent male when male, female, or no bystander present
Placed matched males in adjacent tanks with opaque partition
Familiar treatment – removed partition for 10 minutes
Audience was male or female or no bystander
Removed partitions and recorded male display at opponent
Audience effects in fighting fish + Results + Conclusion
Males displayed highest rate of gill flaring toward unfamiliar opponents with male audience present
Males displayed highest rate of tail beats when female audience present – signaling females
Conclusion:
Signaling behaviour is affected by presence of audience
Intraspecific Deception: False alarm Calls
- within species - less common
1) intra interaction = more common - indiv. learn to ognore inacc. signals faster
2) natural selection favours recievers that discriminate from inacc. signals
Topi Antelope False Alarms
- spot pread - emit snort vocalizations, stare in direction w/ ears pricked up
-females vist multiple male terroties - mate several times - males give calls when no pred are around when females are around - “decive” female to stay
Sexual Deception Hypothesis
The hypothesis that males will produce deceptive signals to females in order to enhance their own reproduction.
Antelope + Methods
researchers observed the behavior
of 53 estrus and 20 non-estrus female
recorded the territorial location of the female, all matings, alarm snorts
recorded all alarm snorts to determine whether true alarm snorts—those produced when a predator was actually present and false alarm snorts differed in acoustic structure
Antelopes + Reults
that alarm snorts given in the presence of predators were acoustically identical to false alarm snorts given in the absence of predators. The researchers observed that false alarms were most likely to be given when an estrus + trying to leave
*females cannot distinguish the difference
Capuchin monkeys + inacc signals
- studies single group - around 24 monkets - unique facial marks
-Two or more “hiccup calls” indicate a high level of danger and often elicit antipredator behavior
-food patches consisting of one to six platforms suspended
in tree branches several meters off the ground
-capuchins produce inaccurate alarm calls to distract others so that they can gain access to clumped food - used sparingly - so they arent overused=ignored
Extended phenotype signal
A signal expressed beyond the body of an
individual that often includes modification of the environment.
- continue functioning in absence of signaler
Bowerbirds + Hypothesis
Construct stick structure - attract mates
Hypothesis - bower functions - signals of male quality
Quantity of decorations correlates with male quality
Bowerbirds + methods + results
22 male birds - over 2 years
recorded # of decor in bower + # of copopulations
Top 5 males - over 50% of copop.
Results: Suggest bower function as signal of male quality
Stickleback + Nest Decorations
RQ: are nest decorations an extended phenotype signal
Methods: Males built nest - add decorations
Control: one piece of algae
All females preferred males whose nest - decorated + Mated w/ decorated nest
Communication Network
comm. system involving a singaler, reciever, bystander
Squirrel Eavsdropping
H: sq. might alter feeding behaviour for diff food items - depend on whether jays were close/ away
M: food patches - food was mixed into pea gravel - forced to dig
Jays vocalize technique to defend faith
All nuts that remained @ the end of the day - GUD=giving up density
R: Jays are nearby - sq. reduce the amount of effort they double to acquiring catchable food - more likely to be lost if caught
Eavesdropping in Tungara Frogs
RQ: can males use the vocalization of others to asses for level of predation risk?
M: 10 minutes - acclimation periods - specific calls played - playbacks continued
Minutes 17-25 - 4 treatments
1. silence 2. repeated co specific call 3. repeated call of lig.. 4. repeated isolated call of eosose frog
R: shortest latency + highest call rate -2,3,4,1
C: Eavesdrop on sympatric + heterospefific vocal signal - asses predation risk
