The mating system of callitrichid primates: I.

Conditions for the coevolution of pair bonding

and twinning

Antu Schamberger, Suzie Banda, and Kristtyn Suarez

Dunbar, R. I. M. (1995). The mating system of callitrichid primates: I. Conditions for the coevolution of pair bonding and twinning. Animal

Behavior, 50, 1057-1070.

Video Clip

Polyandry... It does exist!

Dunbar, R. I. M. (1995). The mating system of callitrichid primates: I. Conditions for the coevolution of pair bonding and twinning. Animal Behavior, 50, 1057-

1070.

Introduction

Callitrichid monkeys have a flexible mating system

Reproduction habits usually result in “twinning” and extensive infant care done by … the males!

Why has there been a move from polygamy to monogamy?

Dunbar, R. I. M. (1995). The mating system of callitrichid primates: I. Conditions

for the coevolution of pair bonding and twinning. Animal Behavior, 50, 1057-1070.

The Basic Model vs. the ESS Model

Two Options for Males and FemalesMales can either be Monogamous or

PolygamousFemales can either produce one or two infants

Dunbar asked just how small of a proportion of twin-producing females will still be worthwhile for males to be monogamous?

Dunbar, R. I. M. (1995). The mating system of callitrichid primates: I. Conditions for the coevolution of pair bonding and twinning. Animal

Behavior, 50, 1057-1070.

Polygamy Roots & Female Counter Strategy

Dunbar cited other studies that show that the amount of territory a male had was related to the number of females he had access to.

Females use 4 strategies

Dunbar, R. I. M. (1995). The mating system of callitrichid primates: I. Conditions for the coevolution of pair bonding and twinning. Animal

Behavior, 50, 1057-1070.

DiscussionMales benefit more from pursuing a polygamous

strategy. When males choose to be monogamous there must be a

strong reasonTwinning evolved as a response to the opportunity to

maximize reproductive outputPair bonding can go both ways, monogamy evolved

because male’s parental care is necessary or parental care evolves because of the advantages it offers to monogamy once it is already set as a mating system.

Dunbar, R. I. M. (1995). The mating system of callitrichid primates: I. Conditions for the coevolution of pair bonding and twinning. Animal Behavior, 50, 1057-

1070.

Critical Review Interesting and informative:

How monogamy is the evolved mating system but the biological external features have not caught up in the female body.

How the stages of monogamy evolved from pair bonding to male parental care to twinning when it was thought to have been other ways.

The author is very thorough in his explanations of mating phenomenon and what he believes to be the reasons from empirical data and analyzes.

Dunbar, R. I. M. (1995). The mating system of callitrichid primates: I. Conditions for the coevolution of pair bonding and twinning. Animal

Behavior, 50, 1057-1070.

Weak cases:The transition from the introduction to the rest of the

paper was a bit confusing because of the fact that as one reads into the paper they are thrown results left and right without knowing how they were attained.

This comes to the idea that there was no methods section. Mostly the author gave examples of captive and wild monkeys but were very vague when it came to strict numbers other than the ones from other studies used as resources.

Finally, it was frustrating to read the conclusion and read about aspects that were not presented in the article. For example, the author goes into the idea of food and how it is important for mating systems. Not exactly clear. Dunbar, R. I. M. (1995). The mating system of callitrichid primates: I.

Conditions for the coevolution of pair bonding and twinning. Animal Behavior, 50, 1057-1070.

Test Questions Females benefit most from

a. Monogamy

b. Polyandry

c. Polygamy

d. Being asexual Research based on territory shows that the max. number of females a male callitrichid could have

is

a. 5

b. 3

c. 2

d. 7 Which is not 1 of the 4 counter strategies a female uses?

a. Reduce interaction with other females

b. Synchronize reproductive cycles

c. Make themselves stand out by using colors

d. Conceal their ovulation T/F: Callitrichid monkeys evolved from polyandry to monogamy T/F: If a female has twins and the male is polygamous, then she will commit infanticide T/F: The bodies of the monkeys evolved just as their mating systems did

Dunbar, R. I. M. (1995). The mating system of callitrichid primates: I. Conditions for the coevolution of pair bonding and twinning. Animal Behavior, 50, 1057-1070