Lecture 12 - Antipredator Behavior

7/28/2019 Lecture 12 - Antipredator Behavior

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ANTI-PREDATOR BEHAVIORPSYCH 118 May 13, 2013

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ANTI-PREDATOR BEHAVIOR

1. Avoid being detected by predators

2. What to do once a predator is encountered

3. More...

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AVOIDING PREDATORS

Blending in to the environment

Keeping quiet

Choosing a safe place

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BLENDING IN

Crypsis: hiding throughcamouflage

Most iconic cases are notbehavioral

Animals can increase crypsisthrough behavior...

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BLENDING IN

Hanlon et al (2007)

Giant Australian cuttlefish(Sepia apama)

86% were camouflaged,

even at night

Controlled behaviorallythrough control ofchromato hores

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BLENDING IN

Uniform patterns (A): very rare, around rocks

Mottled camouflage (B): ~50%, blending to background

Disruptive patterns (C): doesnt look like a cuttlefish...

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BEING QUIET

Remage-Healey et al. (2006)

Gulf toadfish (Opsanus beta)

Dolphins eavesdrop on

theboatwhistle sound ofbreeding males to prey on

them

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BEING QUIET

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BEING QUIET

After exposing male toadfish to the either shrimp or dolphinpopping, they took a blood sample...

Males exposed to dolphin popping gave fewer boatwhistlecalls, but also had higher cortisol

So stress, or cortisol, may be the mechanism by which theboatwhistle call is reduced

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CHOOSING A SAFE PLACE

Brightsmith et al. 2005

Parrot species may either nest intrees or in other types of cavities(e.g., cliffs, termite mounds, etc)

Conducted phylogenetic

analysis, found that tree nestingwas ancestral

So why does nesting in othercavities evolve in parrots?

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Two hypotheses:

1. Competition for treecavities is intense

2. Other cavities maydecrease predationpressure on nestlings

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In past studies, release from competitionalways lead to an increase in clutch size

No evidence of increased clutch size in other-cavity nesting species

In past studies, there was an inversecorrelation between nest predation rateand length of nesting period

Longer nesting periods are found in parrotsthat nest in other cavities

Supports hypothesis that parrotsnesting in other cavities aredoing so to avoid predation

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ENCOUNTERING PREDATORS

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ENCOUNTERING PREDATORS

Alarm calling (see Chapter 8)

Fleeing

Approaching to obtain more information

Feigning death

Signaling to the predator

Attacking the predator

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FLEEING

http://youtu.be/HNbqvqf3-14

Stankowich & Blumstein (2005)

Flight initiation distance: how close a predator can get

before a prey animal flees

Found that FID was mediated by a number of factors...

Tuesday, May 14, 13
http://youtu.be/HNbqvqf3-14http://youtu.be/HNbqvqf3-14


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FLEEINGStankowich & Blumstein (2005)

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EVEN EMBRYOS CAN FLEE...

Warkentin (2000) and red-eyed treefrogs (Agylychniscallidryas)

Eggs hatch more quicklywhen exposed to wasppredation

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EVEN EMBRYOS CAN FLEE...

Eggs also hatched more quickly - immediately - when exposedto snake predation...

Vibrations are the cue!Tuesday, May 14, 13


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APPROACHING PREDATORS

http://www.arkive.org/toque-macaque/macaca-sinica/video-11a.html

Often (but not solely) done by healthy adults

Been called: approach behavior, boldness, investigative

behavior, predator inspection

Prey approach in tentative manner, with momentary pauses,sometimes with a mix ofapproach and leave

Tuesday, May 14, 13
http://www.arkive.org/toque-macaque/macaca-sinica/video-11a.htmlhttp://www.arkive.org/toque-macaque/macaca-sinica/video-11a.htmlhttp://www.arkive.org/toque-macaque/macaca-sinica/video-11a.htmlhttp://www.arkive.org/toque-macaque/macaca-sinica/video-11a.htmlhttp://www.arkive.org/toque-macaque/macaca-sinica/video-11a.html


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Fitgibbon (1994)

Thompsons gazelle

Approach lions and cheetahs(which rely on surprise andambush tactics)

Cheetahs responded by goingfurther away

Approach is a function of groupsize

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FEIGNING DEATH

In response to a predator, aprey animal falls down andremains frozen

Also called tonic immobility

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FEIGNING DEATH

Ohno & Miyatake (2007)

Adzuki bean beetle(Callosobruchus chinensis)

Can either fly away or feign

death

Hypothesis: poor fliers willfeign death more often, andvice versa

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FEIGNING DEATH

Measured how long each individual

would feign death

Dropped beetle through a hole and

recorded how far from center they flew

Two artificial selection experiments:

8 generations of artificial selectionfor either longest or shortest feigners

8 generations of artificial selection

for either best or worst fliers

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FEIGNING DEATHTuesday, May 14, 13


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SIGNALING TO PREDATORS

Signs from prey showing theprobability or consequencesof capture

Often visual, but can also beauditory

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Tail-flagging in ungulates

This could:

Warn conspecifics

Tighten group cohesion

Signal to predator that it has beenspotted

Entice the predator to attack beforeits ready

Cause other groupmates to engagein other antipredator behaviors

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Caro et al. (2004) work supportspursuit deterrence for tail flagging

No time cost

No evidence it is aimed atconspecifics in context of cohesion

Fast-running automatically causes

tail flagging, and so is a cue topredators that I run fast so dontbother

Snorting is a similar deterrent (indicatesvigor and health)

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FIGHTING BACK

http://youtu.be/y6Kd1kg57S4

Prey have many ways offighting back againstpredators

Chemical arsenals

Mobbing behavior

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http://youtu.be/y6Kd1kg57S4http://youtu.be/y6Kd1kg57S4


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FIGHTING BACK: CHEMICALS

Eisner et al.

Bombardier beetles (Stenaptinus insignis)

Produce hydroquanines and hydrogenperoxide by glands in two separatereservoirs

When threatened, reservoirs drain into

a mixing chamber with catalases andperoxidases

Propels resultant acid at high speed (and100 C), direct towards front or backdepending on predator location

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FIGHTING BACK: CHEMICALS

How could this evolve?

Phylogenetic analysis...

Most ancient lineage (Metriuscontractus) has same glands, butdoesnt propel

Froths over rear, or is drained alongwings to the front (and only at 55C)

So chemical defense is ancient, butthe spray and heat are recentlyderived

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FIGHTING BACK: MOBBING

Curio et al. (1978)

Blackbirds (Turdus merula)

Is mobbing a form of cultural transmission?

Experiment: exposed naive blackbirds to twoconditions:

Friarbird with a known predator (owl) and amobbing model

Friarbird with no apparent predator (owl outof sight) and a mobbing model

THEN, exposed another naive bird to the first one(now entrained to the model) to see if they wouldlearn the same...

Transmission chain: 6 birds long!

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PREDATOR SENSITIVE

FORAGING There is often a trade-off

between safety and foraging

Lima & Valone (1986) squirrelsand predator sensitive foraging

Large foods, and small (but moreprofitable, optimal) foods

Placed either close (8m) or far(16m) from safe cover

What happened?

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NEXT TIME...

EXAM 2

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Lecture 12 - Antipredator Behavior