variation in maternal care - between species - within species parent-offspring conflict mothering...
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Variation in maternal care- Between species- Within species
Parent-offspring conflict
MotheringCercopithecines
Baboon mother and infant
Park Ride
Carried
Cling
Nest
Tree
Variation between speciesStyle (park/ride)
The main mammal pattern
(rodents, pigs, ungulates, etc)
Park (nest, branch)
Park + Ride
Ride
Ancestral state unknown
Ross (2001) IJPTarsius
CeboidsCercopithecoidsHumanApes
Daubentonia
Indriidae
Lepilemur
Tree-shrews
Loris
Lorisoids
Galago/oides
Euoticus, Otolemur
Mouse lemurs
Phaner
Varecia
LemurHapalemur
Eulemur
1. Ancestral state = Parking
2. Riding evolved often
3. Riding is maintained
Riding is a repeated primate trait.
Park (nest, branch)
Park + Ride
Ride
Ancestral state unknown Ross (2001) IJP Tarsius
Daubentonia
Indriidae
Lepilemur
Tree-shrews
Loris
Lorisoids
Galago/oides
Euoticus, Otolemur
Mouse lemurs
Phaner
Varecia
Hapalemur
Apes
Cercopithecoids Ceboids
Lemur
Eulemur
Riding: > 4 independent appearances
Park (nest, branch)
Park + Ride
Ride
Ancestral state unknown
Ross (2001) IJPTarsius
CeboidsCercopithecoids
Apes
Daubentonia
Indriidae
Lepilemur
Tree-shrews
Loris
Galago/oides
Mouse lemurs
Varecia
Lemur
Hapalemur
Human
Lorisoids
Euoticus, Otolemur
Phaner
Park+Ride:
> 2 from Park*
> 1 from Ride+
*
*
+
Costs (allometric) of riding, cf. parking:
(1) Smaller home ranges(2) Late weaning(3) Late age of first reproduction
Riding compared to parking:
(1) Same Inter-birth interval(2) Same Growth rate(3) Same Infant size(4) Same Brain size
Retrieving parked infant Arctocebus
So why has riding evolved?
Ho: Improved infant survival
Ross (2001) IJP
Riders: Contact time similar in different species
Mothers carry offspring more when needed
Altmann & Samuels 1992 BES
Kanyawara Field Station (Photo AH)
Mothers are important for survival!
… even when not dead
Mothers are important for RS!
Large group
Small group
Variation within species1. Ecological conditions:
Food availability
Gilgil
Amboseli
Drakensberg
High-quality
Low-quality
% time spent feeding by mother
………… Expected
Observed
Lycett et al 1998 BES
P. c. ursinus Chacma
Harsh conditions:
Infants forage less independently (closer to mother)
Age
% Time
Good habitat
Intermediate habitat
Bad habitat
Twice more independent in a good habitat compared to a bad one !
Lycett et al 1998 BES
P. c. ursinus Chacma
Drakensburg
Harsh conditions:
In harsh environment, mothers work harder.
(infants suckle more)
{ 5x diff.
Good habitatIntermediate habitatBad habitat
Variation within speciesEcological conditions:
Predation Risk
No predation
Some prednMother’s hard work pays!
Variation in maternal care3. Dominance rank / style
High-rank
mothers
carried
less.
Mother’s Style
Laissez-faire Restrictive
Mother’s rank High Low
Infant allowed to leave < 2 months Later
M follows I Rare Common
M joins I Rare Common
M punishes I Less More
M-I contact Less More
Altmann (1980)
Variation in maternal care
Maternal style
Parent-Offspring conflict: OBSERVER’S Perspective
B = Benefit to Offspring(e.g. 10 cc of milk)
C = Cost to Mother(e.g. extra daysbefore next birth)
Age of Offspring
B/C
WEANING CONFLICTAGREED: M CARES
AGREED: M STOPS
B=C
When to wean? MOTHER’S Perspective
B/2 = Benefit to Mother
? ??
B = Benefit to Offspring
C = Cost to Mother
Age of Offspring
B/C
Wean when “rB < C”i.e. when B/2 < C
C/2 = Cost to Offspring
When to wean? OFFSPRING’S Perspective
B = Benefit to Offspring(e.g. 10 cc of milk)
C = Cost to Mother
Age of Offspring
B/C
Wean when “B < rC”i.e. when B < C/2
Wean when “B < rC”i.e. when B < C/2
C/2
B
Age of Offspring
B/2C
Age of Offspring
Wean when “rB < C”i.e. when B/2 < C
“EARLY!!” “LATE!!”CONFLICT!!!
WHY PARENTS AND CHILDREN FIGHT
Parent-offspring conflict
Infant age (weeks)
3030
25
50
Cayo Santiago
(feral, subtropic)
Madingley
(cages, UK)
% total nipple contacts
(attempted + successful) rejected by
mother
Mothers do reject young
Infant age (weeks)
3012
Relative Responsibility Index: RRI
RRI = (% M-I body contacts initiated by infant) -
(% M-I body contacts terminated by infant)
RRI
0
25
50
25
50
I joins and/or M leaves
M joins and/or I leaves
Who’s responsible for declining maternal investment?
Mother’s investment falls
Gelada:
More infant contact during
RESTING SOCIALIZING
than during
FEEDING MOVING
Contact MOTHER
Contact NIPPLE
Infants seek investment mostly when mother is not busy
Infant age (months)
987654321
Re
jectio
ns p
er
min
of
activity
.040
.030
.020
.010
0.000
Context
Feeding
Socializing
Gelada: Rejections occur almost entirely when mother is feeding
No rejections were observed during
moving and resting
Time on nipple
Ventral + Nipple
Suckling time decreases little!
van Schaik & van Noordwijk (1999) Primates
Mothers need to wean early to increase their lifetime RS
Age-specific fecundity Macaques (3 species)
Parent-offspring conflict:
Amount versus Timing
Barrett et al 1995 Anim Behav
PlayFightingAllomotheringLearning
Juvenile relationships
Childhoodin
Macaques
Macaca fuscata
Japanese macaque
Benefits of Play: cf. going to school
Benefit to young: Skills?
Lone play M = F
Play-fighting M > F NHP’s
Play-mother F > M NHPs’
Tool-use F > M Tai, Gombe
Social manipulation?
Mother distracting Infant (weaning)
Learning competition
Early coalitions/relationships?
Benefits of Play: cf. going to schoolLone play M = F
Benefits of Play: cf. going to schoolPlay-mother F > M NHPs’
Benefits of Play: cf. going to schoolPlay-fighting M > F NHP’s
Benefits of Play: cf. going to schoolTool-use F > M Tai, Gombe
Rainfall
% play-time
Economics of play
(1) Benefit
More play when more food
Some primates never play!
Economics of play(2) Cost
Vervets eaten when playing – Red-tailed infant playing at the very top of a fruit tree (Kibale) caught by eagle
Vervet allomothers (captive)
Who?
Juvenile ff 65
(sibs; high-rank)
Adult ff 25
Juvenile mm 7
Adult mm 3
Benefit to mother
Why be an alloparent?Females - nulliparous
*** Practice: improved mothering ** Nepotism: caring for kin * Market forces: care for HR’s offspring (get support in return)
Females - parous (e.g. langurs) * Nepotism * Non-kin: odd
suggesting friendship?
Males - juvenile * Nepotism * Practice mating * Market forces: care for HR’s offspring (get support in return)
Males - adult ** Paternal care*** Mating effort
Wallen et al. (1995) Hormones and Behavior
14
7
0
DaughterSon
Yearling-controlled
proximity to mother
(% time)
Girls spend more time with mother than boys
Rhesus macaque
Wallen et al. (1995) Hormones and Behavior
14
7
0
Daughter
Sons
Yearling-controlled
proximity to mother
(% time)
Neonatal T affects how much time boys spend with mother
T control T T
Rhesus macaque
Lonsdorf et al 2004 Nature
% time at mound spent termite-fishing: girls > boys
Termites per dip
Lonsdorf et al 2004 Nature
Mother’s % dips at given tool length
Daughter’s % dips at given tool length
Lonsdorf et al 2004 Nature
Mother’s % dips at given tool length
Son’s % dips at given tool length
Juvenile relationships: anticipating adulthood
Dominance relations in FB-groups
Juv F Juv M
Juv F Maternal Rank Size
Juv M Size Size
e.g. Pereira, Amboseli baboons
Juvenile relationships: anticipating adulthood
Infant Juvenile Adult
Pereira, Amboseli baboons
0 30 (months) 60
# Supplants received per hour from HR females Female
Male
Juvenile relationships: anticipating adulthood
Juv F Juv M
Challenged by Adult FF YES NO
Supported by Adult FF YES NO
‘Head-flag’ to Adult FF YES NO
“ “ Adult MM NO YES
Non-kin supported HR-FF Juv MM
Pereira, Amboseli baboons
Baboon rules for treating juveniles
Adult FF
Juvenile FF: support their rank
(winner support)
Juvenile MM: dominate as long as possible
Adult MM
Ignore sex/rank (dominate all)
Support possible offspring
Old view New view
Juvenile Passive Active
Juv period Long, to learn Fast growth, risky
Major influences Proximate Ultimate
(experience) (social system)
Quality of life Relaxed Dangerous (>50% die)
23 FF, 2 groups, 240 cases
90% held I’s = higher-rank
F > M
Kin > Unrelated
De Waal 1990 Primates
“Double-holding”:
Play
Play partners
Infants Same size
HR preferred
Juv FF Infants (HR preferred)
Juv MM Juv MM