Hamadryas Baboons

1
Hamadryas Baboons
2
(No Transcript)
3
(No Transcript)
4
(No Transcript)
5
Hamadryas vs Savanna Baboons
Hamadryas Arabia, N-E Africa dry country, less
fruit, less grass? Separate 340,000
years Hamadryas 20-25 smaller Dimorphism H MM
striking from 3-4 years Long mane white
whiskers pink face, perineum
6
Fertile hybrids --- same species! Papio
hamadryas e.g. Hamadryas Papio hamadryas
hamadryas Anubis Papio hamadryas anubis
7
(No Transcript)
8
Troops Sleeping groups
9
Hamadryas Social Organization
Troop Up to gt 600 Sleeping community only
Band Largest social unit ( 30-100) May
travel together or disperse May fight other
bands ? No M-M fighting within bands
Clan Sub-band (10-20) May forage
independently MM may look alike (e.g.
Reds) Little M/F dispersal
10
Fights between bands
Inter-band supplanting
11
Fights between bands
Near band approaches. Fight starts on right.
12
Fights between bands
Inter-male contest for FF
M(R) chases M(L)s F. M(L) intervenes.
2
1
13
Fights between bands
FF in M(L)s attack shadow. M(L) does not engage
in battle.
Body weight FF 14.7 kg MM 28.4 kg (twice FFs
body weight !)
14
Family (one-male unit) within clans
Prime M, FF (2-3, range 1-9) M leader 70
bonds last gt 3 years
15
M dominates FF within unit Most grooming is by F
to M M can summon F with a look
16
M defends his infant Certainty of paternity?
17
High-ranking mothers are more permissive
parents. Low-ranking mothers keep tight control
on their infants whereabouts, sometimes by
holding her infant by the tail.
N. Rowe, 1996
18
M intervenes if any other M tries to interact
with his females
19
Female-female aggression within OMU coalitions
only with male! Like among gorillas
FF compete for M (e.g. by being child-like)
20
Female-female aggression within OMU coalitions
only with male!
Double signal by female. Present to M threaten
opponent F.
21
Protected threat (seen only in captivity).
F(A) moves so as to be between M and F(B) (and
presents to M). So F(B) cant threaten F(A)
without threatening M also.
22
Paternity
Strong M-M respect No matings seen by other
males within clan Contracepted MM FF ? stop
breeding
FF solicit their own MM only Anti-infanticide
strategy by FF?
23
Coordination
How to meet at water-hole after leaving
sleeping-cliff?
1. Mental map? Probable. Places visited more
often are reached by more detours.
2. Communication of intention? Probable.
Clans separate 250 m from cliff Reassemble at
noon to drink/rest Joint direction pre-fission
(250 m) waterhole direction Notifying at high
rates
Male notifies to ally (before turning R)
Ho MM make appointments within bands
24
Life-history of hamadryas OMU
1. Initial unit. Young AM (9-11 yr) Juv F (2-3
yr) No mating (F too young) M herds, carries,
sleeps-embracing F
25
1. Initial unit
Formation Follower-M forms bond with Juv F M
herds lie flat and watch walk ahead / look
back invite groom. N.B. This establishes
respect by other MM before FF mates
Nervous mother
26
1. Initial unit
Grooming between MM of initial units
N.B. No grooming among breeding males!
27
1. Initial unit
Maternal Male in initial unit
28
2. Take-over Fight
Prime M loses FF to (A) Non-breeding M within
clan (e.g. Follower M) or (B) Neighboring
band but No fight/take-over within the clan (M-M
respect) Question Higher risk of take-over if
more FF in the OMU?
29
Male stages within clan
STATUS
Past prime BACHELOR FORMER LEADER
Prime OMU LEADER
Late adolescent INITIAL UNIT LEADER FOLLOWER
Early adolescent BACHELOR FOLLOWER
30
How do MM in OMUs avoid losing FF?
Kummers field experiments
1. What creates the Hamadryas M-F bond?
Ho Male herding behavior.
Transplant Anubis F into Hamadryas band 1 H-M
herds (rocks cage, neck bite, expects follow
etc) A-F follows within 1 hour!!
Conclusion H-M herding -gt M-F bond
BUT A-F keeps straying!!! After a week, H-M
gives up!!
Conclusion H-M herding H-F following -gt M-F
bond
31
2A. What protects the Hamadryas M-F bond within
Bands?
Ho Breeding MM within Bands respect each
others relationships with FF.
Transplant H OMU to different H Troop! (at dawn)
--gt M loses FF within 1 hour
Conclusion M-M respect within bands protects the
M-F bond.
32
2B. What protects the Hamadryas M-F bond within
Bands? Mechanism?
Ho MM respect within Bands comes from observing
M-F relationship.
Test M-M dominance within a Band (HM1, HM2) e.g.
peanut test --gt (HM1 gt HM2) Introduce new F to
Low-rank M (HM2) Allow high-rank HM1 to watch for
15 minutes (cf. Control, watch 0 min) Introduce
dominant HM1 to (F subordinate HM2)
--gt HM1 is inhibited cf. Control, HM1 attacks!
Conclusion M-M respect within bands results from
knowing M-F bond.
33
(No Transcript)
34
F has been placed on top of HM1s cage. HM1 moves
as far as possible, and turns away. HM2 grabs for
F without inhibition.
35
2B. What protects the Hamadryas M-F bond within
Bands?
Ho MM respect within Bands comes from observing
M-F relationship.
Control experiment MM do not observe each other
with F.
36
2C. Does F choice influence M respect?
Ho MM show less respect to the M-F bond if FF
dont like their own M.
Test Rank F preference for M approach, groom,
etc Allow Rival MM to attack/respect Result MM
attack more if F preference for her own M is
low.
Conclusion M-M respect within bands results
from 1- M1 knowing M2-F bond, AND 2- from
assessing Fs preference for her own male.
37
Species differences in Sexual Behaviors
Anubis
Hamadryas
Band
Clan
OMU
?
?
?
?
?
?
?
?
?
?
?
?
?
?
?
?
?
?
?
?
?
?
?
?
?
?
?
?
?
?
?
?
?
?
?
Anubis
Hamadryas
38
Species differences in Sexual Behaviors
Anubis
Hamadryas

• Hamadryas (compared to anubis)
• less fighting
• no dispersal
• more sexual consorting

39
Species differences in Serotonin
Anubis
Hamadryas

• Serotonin is neurotransmitter and hormone.
• It acts as a sexual inhibitor.

• When serotonin is reduced in the body (with a
  neurotoxin), sexual activities are increased in
  male rats.

• Increasing the serotonin activity in the brain
  (with drugs) result in reductions of sexual
  behavior in male rats, or
• inhibits erection in the male rhesus monkey

Dixon (1998). Primate Sexuality
40
SEROTONIN BEHAVIOR VARIATION BETWEEN SPECIES
Hamadryas baboon
Savanna (anubis) baboon
41
Species differences in Serotonin
Anubis
Hamadryas
Serotonin index
Hybrids inhibited males
Kaplan et al (1999)
42
(No Transcript)
43
(No Transcript)
44
(No Transcript)
45
See you next time !
46
Hybrid troops
Complex mixture of relationships some bonding,
some not
Origin Hamadryas Mate-raiding? Expected, but
not seen Immigration by Hamadryas and Anubis MM
-- yes
Morphology and Behavior correlated in the
hybrids? Score MM by 7 physical features (e.g.
mane length) 7 behavioral features (e.g.
herding)
Result Hybrids behavior and looks are
correlated.
47
Hamadryas and evolutionary history.
Hamadryas and anubis differ consistently (wild
captive) Female coalitions (H-, A) Female
willingness to be herded (H, A-) Male herding
(H, A-) Male respect (H, A-)
What explains the Hamadryas system?
A. Low food density --gt small groups
Kummer/Dunbar male protects vs. predators
Henzi/Barret male protects vs. infanticide
Wrangham FF coalition in Indian langurs against
Infanticide FF coalition in olive and yellow
baboons ? Infanticide rare But chacma FF allies
occur but rarely, similar to Hamadryas!