Raoul Mulder
Animal Behaviour Raoul Mulder
Mating systems: caring males
If male care is essential and experienced pairs have higher reproductive success, monogamy may be optimal for both sexes Example: Oystercatchers Experienced pairs do best
Production of eggs/chicks
Monogamy as best option
Eggs
Chicks
Short (1-2)
Medium (6-8)
Long (12+)
Duration of pair bond (years)
Monogamy as constraint Male care is often important, but not essential
Song sparrow
Desertion should be profitable for males if they can improve their reproductive success Conclusion: monogamy is not optimal; arises when opportunities for polygyny are limited !
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+
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Monogamy as constraint Male care is often important, but not essential Desertion should be profitable for males if they can improve their reproductive success Conclusion: monogamy is not optimal; arises when opportunities for polygyny are limited Constraints: 1) competition among males 2) female resistance
Burying beetle
Extra-pair mating ‘Extra-pair’ paternity (EPP) allows males to increase reproductive success without providing parental care
Red-winged blackbird
21% EPP
Superb fairy-wren
76% EPP
Answer: He can compensate for the loss in offspring survival through additional matings. Correct. Desertion (and the subsequent decrease in parental care) will typically decrease his reproductive fitness for that particular brood of offspring. Therefore, it is only profitable for a male if he can mate with enough additional females to compensate for this loss. That is, if the loss from desertion is 1 / x, he must mate with an additional x females for desertion to be worthwhile.
Resource-defence polygyny Polygyny occurs when males are able to monopolise resources that matter to females When males contribute little care, there is minimal cost to females
Yellow-rumped cacique
Resource-defence polygyny Polygyny occurs when males are able to monopolise resources that matter to females When males contribute little care, there is minimal cost to females When there are costs (sharing), polygyny may mean females have ‘no choice’, or it is ‘the best of a bad job’ Marsh wren
Polygyny threshold model monogamy Reproductive success
Should a female mate with a polygynous male with good resources, or a monogamous male with poor resources?
polygyny
Territory quality
Polygyny threshold model polygyny threshold
Polygyny threshold: minimum quality difference necessary to make polygyny beneficial for female
monogamy Reproductive success
Should a female mate with a polygynous male with good resources, or a monogamous male with poor resources?
polygyny
Low
High
Territory quality
Testing the model Female reed warblers extensively sample males before settling; opt for polygyny even if monogamy is available Polygynous females claim territories with the best nest sites (dense reed beds where predation is low), and have similar fitness to monogamous females
Great reed warbler
Summary Where males provide care, males become a resource for females Monogamy may the best option for both sexes because cooperation is essential to breeding success; but it may also result from constraints (competition and female resistance) The polygyny threshold model predicts when it should pay females to opt for polygyny
PDF Citations Slide 1 _MG_2581 peacock spider Maratus volans by Jurgen Otto (http://www.flickr.com/photos/59431731@N05/5521738809/). Reproduced with permission from Jurgen Otto. Slide 2 a) Oystercatchers 5 < https://www.flickr.com/photos/aldenchadwick/13080625703/> by Alden Chadwick (modified by Milly Formby) (CC BY 2.0) b) Graph by Raoul Mulder, based on data from van de Pol 2006 Experimental evidence for a causal effect of pair-bond duration on reproductive performance in oystercatchers. Behavioural Ecology 36:982-991 Slide 3 a) Song Sparrow- 27527 – 2 (http://commons.wikimedia.org/wiki/File%3ASong_Sparrow-27527-2.jpg) by Ken Thomas (KenThomas.us (personal website of photographer)) [Public domain], via Wikimedia Commons b) Birds in nests by Eunice Tan © University of Melbourne c) "sign icon blue symbol boy man female male woman" (http://pixabay.com/en/sign-icon-blue-symbol-boy-man-24171/) by Nemo [Public Domain] d) " sign black icon symbol boy man female male " (http://pixabay.com/en/sign-black-icon-symbol-boy-man-24170/) by Nemo [Public Domain]. Slide 4 a)
Sexton Beetle https://www.flickr.com/photos/55663585@N00/6002167001/ by Alastair Rice (CC BY-SA 3.0)
Slide 5 a) Agelaius phoeniceus 0110 taxo (http://commons.wikimedia.org/wiki/File:Agelaius_phoeniceus_0110_taxo.jpg) by Walter Siegmund (Own work) (CC-BY-SA-3.0), via Wikimedia Commons b) Superb fairy wrens mark 2 (http://commons.wikimedia.org/wiki/File:Superb_fairy_wrens_mark_2.jpg) by user:benjamint444 (Own work) (CC-BY-SA-3.0), via Wikimedia Commons Slide 7 “Yellow-rumped cacique and nests in Peru” http://en.wikipedia.org/wiki/File:Cacicus_cela_-Peru_-nest-8.jpg#file by Paucarcillo, via Wikimedia Commons Slide 8 Marsh Wren (http://www.flickr.com/photos/60509459@N00/4682074616/) by Carly Lesser & Art Drauglis (CC BY-SA 2.0) Slides 9 & 10 Polygyny threshold graph by Raoul Mulder modified from (http://en.wikipedia.org/wiki/File:Polyganythresholdmodel_1.svg) by Opakrapaka [Public Domain], via Wikimedia commons Slide 11 Cannereccione (http://www.flickr.com/photos/16994729@N03/2520886147/) by M. Albi (CC BY-SA 2.0)
Mating systems: caring males
If male care is essential and experienced pairs have higher reproductive success, monogamy may be optimal for both sexes Example: Oystercatchers Experienced pairs do best
Production of eggs/chicks
Monogamy as best option
Eggs
Chicks
Short (1-2)
Medium (6-8)
Long (12+)
Duration of pair bond (years)
Monogamy as constraint Male care is often important, but not essential
Song sparrow
Desertion should be profitable for males if they can improve their reproductive success Conclusion: monogamy is not optimal; arises when opportunities for polygyny are limited !
!
+
!
only
Monogamy as constraint Male care is often important, but not essential Desertion should be profitable for males if they can improve their reproductive success Conclusion: monogamy is not optimal; arises when opportunities for polygyny are limited Constraints: 1) competition among males 2) female resistance
Burying beetle
Extra-pair mating ‘Extra-pair’ paternity (EPP) allows males to increase reproductive success without providing parental care
Red-winged blackbird
21% EPP
Superb fairy-wren
76% EPP
Answer: He can compensate for the loss in offspring survival through additional matings. Correct. Desertion (and the subsequent decrease in parental care) will typically decrease his reproductive fitness for that particular brood of offspring. Therefore, it is only profitable for a male if he can mate with enough additional females to compensate for this loss. That is, if the loss from desertion is 1 / x, he must mate with an additional x females for desertion to be worthwhile.
Resource-defence polygyny Polygyny occurs when males are able to monopolise resources that matter to females When males contribute little care, there is minimal cost to females
Yellow-rumped cacique
Resource-defence polygyny Polygyny occurs when males are able to monopolise resources that matter to females When males contribute little care, there is minimal cost to females When there are costs (sharing), polygyny may mean females have ‘no choice’, or it is ‘the best of a bad job’ Marsh wren
Polygyny threshold model monogamy Reproductive success
Should a female mate with a polygynous male with good resources, or a monogamous male with poor resources?
polygyny
Territory quality
Polygyny threshold model polygyny threshold
Polygyny threshold: minimum quality difference necessary to make polygyny beneficial for female
monogamy Reproductive success
Should a female mate with a polygynous male with good resources, or a monogamous male with poor resources?
polygyny
Low
High
Territory quality
Testing the model Female reed warblers extensively sample males before settling; opt for polygyny even if monogamy is available Polygynous females claim territories with the best nest sites (dense reed beds where predation is low), and have similar fitness to monogamous females
Great reed warbler
Summary Where males provide care, males become a resource for females Monogamy may the best option for both sexes because cooperation is essential to breeding success; but it may also result from constraints (competition and female resistance) The polygyny threshold model predicts when it should pay females to opt for polygyny
PDF Citations Slide 1 _MG_2581 peacock spider Maratus volans by Jurgen Otto (http://www.flickr.com/photos/59431731@N05/5521738809/). Reproduced with permission from Jurgen Otto. Slide 2 a) Oystercatchers 5 < https://www.flickr.com/photos/aldenchadwick/13080625703/> by Alden Chadwick (modified by Milly Formby) (CC BY 2.0) b) Graph by Raoul Mulder, based on data from van de Pol 2006 Experimental evidence for a causal effect of pair-bond duration on reproductive performance in oystercatchers. Behavioural Ecology 36:982-991 Slide 3 a) Song Sparrow- 27527 – 2 (http://commons.wikimedia.org/wiki/File%3ASong_Sparrow-27527-2.jpg) by Ken Thomas (KenThomas.us (personal website of photographer)) [Public domain], via Wikimedia Commons b) Birds in nests by Eunice Tan © University of Melbourne c) "sign icon blue symbol boy man female male woman" (http://pixabay.com/en/sign-icon-blue-symbol-boy-man-24171/) by Nemo [Public Domain] d) " sign black icon symbol boy man female male " (http://pixabay.com/en/sign-black-icon-symbol-boy-man-24170/) by Nemo [Public Domain]. Slide 4 a)
Sexton Beetle https://www.flickr.com/photos/55663585@N00/6002167001/ by Alastair Rice (CC BY-SA 3.0)
Slide 5 a) Agelaius phoeniceus 0110 taxo (http://commons.wikimedia.org/wiki/File:Agelaius_phoeniceus_0110_taxo.jpg) by Walter Siegmund (Own work) (CC-BY-SA-3.0), via Wikimedia Commons b) Superb fairy wrens mark 2 (http://commons.wikimedia.org/wiki/File:Superb_fairy_wrens_mark_2.jpg) by user:benjamint444 (Own work) (CC-BY-SA-3.0), via Wikimedia Commons Slide 7 “Yellow-rumped cacique and nests in Peru” http://en.wikipedia.org/wiki/File:Cacicus_cela_-Peru_-nest-8.jpg#file by Paucarcillo, via Wikimedia Commons Slide 8 Marsh Wren (http://www.flickr.com/photos/60509459@N00/4682074616/) by Carly Lesser & Art Drauglis (CC BY-SA 2.0) Slides 9 & 10 Polygyny threshold graph by Raoul Mulder modified from (http://en.wikipedia.org/wiki/File:Polyganythresholdmodel_1.svg) by Opakrapaka [Public Domain], via Wikimedia commons Slide 11 Cannereccione (http://www.flickr.com/photos/16994729@N03/2520886147/) by M. Albi (CC BY-SA 2.0)
