Infant Handling and Maternal Response in Japanese Macaques

1
Infant Handling and Maternal Response in Japanese
Macaques
Schino, et. al., Presented by Elizabeth Peterson

• METHODS
• Organism - Japanese macaques (Mucaca fuscata)
• Recorded infant social interactions
• 1) Allomaternal behavior (positive handling)
• 2) Hand touch and inspection (neutral
  handling)
• 3) Aggression (negative handling)
• 4) Social play
• Recorded maternal protective responses
• 1) Aggression towards infants interactant
• 2) Restraint or retrieving infant
• Used protection index (proportion of bouts of
  infant social
• interaction where mothers responded
  protectively) and statistical
• tests

TEST NO. 2
ABSTRACT We focused on the social interactions
of infant Japanese macaques (Mucaca fuscata) and
on the protective response of their mothers to
such interactions. Infant social interactions
included received allomaternal behavior
(positive infant handling), hand touch and
inspection (neutral handling), and aggression
(negative handling) as well as social play.
Maternal protective responses included aggression
to the infants interactant and restraining or
retrieving the infant. All types of social
interactions as well as the maternal response to
such interactions showed clear developmental
variations. Frequency of infant social
interactions and maternal protective responses
also showed large interindividual variability.
Juvenile and subadult females without maternal
experience were the most frequent infant
handlers. Infants received positive handling
primarily from their kin, while mothers were
equally protective in response to positive
handling received by kin and non-kin.
Conversely, kin showed higher levels of neutral
handling and their interest was more easily
tolerated by mothers compared to that of non-kin.
RESULTS
TEST NO. 1
Fig. 2. Maternal protective response to various
social interactions directed to the infant in
relation to infant age (a) through (d) same as
Figure 1.
BACKGROUND
Note Mothers responded strongest to negative
handling (protection index 0.35 0.16) and
progressively less to neutral (0.27 0.03) and
positive (0.19 0.03) handling and social play
(0.17 0.04). Maternal protective responses
monotonously decreased with increasing infant age
while peaking at 4-6 weeks in positive and
neutral then declining (Friedman ANOVA P lt 0.02).

• Japanese Macaques (Mucaca fuscata)
• Infant dependent on mother for
• survival
• Mother-infant bond strong
• Evolution of Non-maternal Infant Handling
• Non-maternal handling occurs
• with infants
• Mothers reluctant to allow it
• Little known about
• interindividual variability and
• kinship in maternal response

TESTS NO. 3 AND 4
Test No. 3 Infant social interactions differed
significantly over age/sex classes. Social play
interactions occurred mostly with other male and
female infants (Kruskal-Wallis ANOVA P lt 0.0001)
while positive and neutral handling were highest
with females (P lt 0.0001). Negative handling was
too rare to conduct a statistical analysis. Test
No. 4 More positive handling occurred from kin
(Wilcoxon matched pairs test P lt 0.05). Neutral
handling occurred more in kin (P lt 0.01) while
mothers were more protective with nonkin (P lt
0.01). Negative handling occurred at similar
frequencies from kin and nonkin it was too rare
to calculate statistically.

• PURPOSE
• 1) Investigate non-maternal infant handling and
  responses of
• mothers to their infants social interactions
• Compare maternal responses in different
  interactions
• 3) 4 tests
• 1) frequency of four types of handling (see
  methods)
• 2) maternal responses to four types of
  handling
• 3) frequency of four types of handling in
  terms of age/sex
• class of interactant directed to infant
• 4) frequency of only positive and negative
  handling by kin
• and nonkin and the maternal protective
  response to both
• types of handling by kin and nonkin

Fig. 1. Frequency of various infant social
interactions directed to the infant in relation
to infant age (a) positive infant handling, (b)
neutral infant handling, (c) infant social play,
(d) negative infant handling.

• CONCLUSION
• Infants were involved in all four types of
  social interaction but
• involvement differed based on developmental
  stages and age/sex
• class
• Maternal protective response depended on infant
  age and kinship (kin
• or nonkin) of interactant
• Supported by previous studies

Note Various social interactions occurred with
infants in different frequencies (Friedman ANOVA
P lt 0.0001). Social play was most common
interaction by infants (55.7 4.7 int/h).
Neutral handling (14.3 5.4 int/h) was the
second popular interaction then positive handling
(3.5 0.9 int/h), and finally negative handling
(1.0 0.5 int/h). Clear developmental
variations between infant social interactions and
group companions. Neutral and negative handling
interactions peaked at 7 weeks then declined.
Positive interactions and social play kept
increasing during the 12 weeks.