Chapter 4: Swords or Chapter 4: Swords or Pistols?Pistols?

A Biological Guide to Fighting A Biological Guide to Fighting by:by:

Kelsey Barker, Jose Bonilla Kelsey Barker, Jose Bonilla and Brittnae Stewartand Brittnae Stewart

IntroductionIntroductionIn nature, fighting is not always the In nature, fighting is not always the

answer. answer.

Knowing when to fight, Knowing when to fight,

when to run, when to run,

or when to throw sand in or when to throw sand in

your opponent’s face your opponent’s face

is the key to evolutionary is the key to evolutionary

success.success.

““Fight when you have nothing Fight when you have nothing to lose”to lose”Fig wasps Fig wasps 11

Live inside figs. Males don’t have wings, so Live inside figs. Males don’t have wings, so the only time to mate is right after hatching.the only time to mate is right after hatching.

Two types of fig waspsTwo types of fig wasps

PollinatorsPollinators Fighters (parasitic)Fighters (parasitic)Lovers, generally Lovers, generally die before matingdie before mating

Fighters, will fight Fighters, will fight to death and to death and winner gets to winner gets to matemate

““Fight when you have nothing Fight when you have nothing to lose” – Other examplesto lose” – Other examples

Gladiator frogs Gladiator frogs 1 1 – Have – Have sharp, retractable spine sharp, retractable spine which they only use to which they only use to fight other frogs. Aim is fight other frogs. Aim is for eyes and eardrums.for eyes and eardrums.

Reason for this is that Reason for this is that they have a short life they have a short life span and rarely live from span and rarely live from one breeding season to one breeding season to the next, so there exists the next, so there exists a lot of competition.a lot of competition.

““Fight when you have nothing Fight when you have nothing to lose” – Other examplesto lose” – Other examples

““Annual” fishes of Annual” fishes of Africa and South Africa and South America America 1 1 – live in – live in puddles until they dry puddles until they dry up.up.

Once the puddles dry Once the puddles dry up, only their eggs up, only their eggs survive.survive.

This creates a struggle This creates a struggle to reproduce and to reproduce and facilitates aggressive facilitates aggressive male competition.male competition.

““Don’t fight if you know you’re Don’t fight if you know you’re going to lose”going to lose”

African elephant African elephant 11

Go into musth, anger Go into musth, anger and lust at the same and lust at the same timetime

Females prefer older, Females prefer older, stronger malesstronger males

The bigger an elephant The bigger an elephant is, or the more is, or the more aggressive it acts, the aggressive it acts, the higher the likelihood that higher the likelihood that it will win a fightit will win a fight

Males often avoid each Males often avoid each other during this time, so other during this time, so as to save themselves as to save themselves the struggle of fightingthe struggle of fighting

Two-spotted spider mites Two-spotted spider mites 11 – protects – protects female until female molts, whenever fights female until female molts, whenever fights start, smaller male usually retreatsstart, smaller male usually retreats

Flies measure length between eye stalks, Flies measure length between eye stalks, the fly with the shorter stalk usually the fly with the shorter stalk usually retreatsretreats

““Don’t fight if you know you’re Don’t fight if you know you’re going to lose” – Other going to lose” – Other

examplesexamples

““Don’t fight if you know you’re Don’t fight if you know you’re going to lose” – Other going to lose” – Other

examplesexamples Lobsters engage in fights to establish Lobsters engage in fights to establish

dominance relationships, and they dominance relationships, and they often remember who they have often remember who they have fought withfought with

““Fight dirty when you can”Fight dirty when you can”

Xylocoris maculipennisXylocoris maculipennis (pirate bug) (pirate bug) 11

Can jab penis through another males Can jab penis through another males body wall in order to inject sperm body wall in order to inject sperm into other maleinto other male

This is possible, but unlikely. This is possible, but unlikely. Scientists are still researchingScientists are still researching

““Fight dirty when you can” – Fight dirty when you can” – Other examplesOther examples

Moniliformis dubis Moniliformis dubis 11 (spiny-headed worm) (spiny-headed worm) finishes mating with female and caps off finishes mating with female and caps off genitalia with “cement” chastity belt; also genitalia with “cement” chastity belt; also does so with malesdoes so with males

Male African bat bedbugs Male African bat bedbugs 11 have false have false sperm receptors, so can trick males into sperm receptors, so can trick males into depositing their sperm, thus making their depositing their sperm, thus making their rivals waste valuable spermrivals waste valuable sperm

““Feel free to sabotage others Feel free to sabotage others to further your mating to further your mating

chances”chances”

Three-spine stickleback Three-spine stickleback 11

Males steal eggs for own nestMales steal eggs for own nest Makes male look better to others – Makes male look better to others –

more females will want to leave their more females will want to leave their eggs with himeggs with him

Will lessen chances of other male to Will lessen chances of other male to get more eggsget more eggs

““Feel free to sabotage others to further Feel free to sabotage others to further your mating chances” – Other your mating chances” – Other

ExamplesExamples Bowerbirds Bowerbirds 11 – –

vandalize or vandalize or destroy each destroy each others bowersothers bowers

Cheat Sheet for fightingCheat Sheet for fighting

1.1. Will this be your only chance to mate?Will this be your only chance to mate?

If yes, proceed to question 2If yes, proceed to question 2

2.2. If you fight now, will it help you If you fight now, will it help you become successful in mating with become successful in mating with more females?more females?

If yes, proceed to question 3If yes, proceed to question 3

3.3. Are you the biggest? Do you have a Are you the biggest? Do you have a good chance of winninggood chance of winning

If yes, FIGHT!!!If yes, FIGHT!!!

Remember, when you’re Remember, when you’re fighting, bigger almost fighting, bigger almost always means better, always means better,

running does not mean running does not mean you’re a coward, watch you’re a coward, watch closely for cheaters, and closely for cheaters, and don’t be above cheating don’t be above cheating

yourselfyourself

BibliographyBibliography

1.1. Judson, Olivia. Judson, Olivia. Dr. Tatiana’s Sex Advice to All Dr. Tatiana’s Sex Advice to All Creation.Creation. New York: Henry Hold and Company, New York: Henry Hold and Company, 20022002

2.2. Kravitz, Edward, PhD. Kravitz, Edward, PhD. Fighting Lobsters and Fighting Lobsters and Fighting Flies: Two Model Systems for the Study Fighting Flies: Two Model Systems for the Study of Aggression. of Aggression. http://www.harvard.edu/bss/neuro/kravitz/currehttp://www.harvard.edu/bss/neuro/kravitz/currentresearch.htmlntresearch.html May 25, 2005 May 25, 2005