Specialization in the Standing Guard Duty of Captive Meerkats

1
Specialization in the Standing Guard Duty of
Captive Meerkats (Suricata suricatta) By Jason
Gue 1. Fort Lewis College, Department of Biology,
Durango, CO. 2. Cheyenne Mountain Zoo, Colorado
Springs, CO.
CHEYENNE MOUNTAIN ZOO

INTRODUCTION

• KEY FINDINGS
• In captivity male meerkats conduct more standing
  guard than females
• Subordinates conduct more standing guard than
  the Dominant pair in captivity
• In captivity different litters conduct more
  standing guard than others
• In captivity there is an interaction between the
  time of day and litter when conducting standing
  guard
• In captivity this is no connection between time
  of day and gender

A meerkat (Suricata suricatta) is a diurnal,
desert-adapted social mongoose that lives in
groups called mobs that consist of 2 to 30
individuals in Southern Africa (Macdonald, 1986
Clutton-Brock et al., 1999). Meerkats contribute
within their mob by conducting several different
cooperative behaviors. The most common behaviors
are babysitting the pups (1-3 months old),
pup/juvenal feeding (2-6 months old), social
digging of burrows, group foraging and
anti-predator defenses (Macdonald, 1986
Bednekoff, 1997 Clutton-Brock et al., 1998,
2002). The standing guard behavior is one of the
anti-predator defenses, where an individual
leaves foraging to obtain a position that is
relatively unprotected to observe for potential
predators (Bednekoff, 1997) Clutton-Brock et al.
(2003) studied social behavior by meerkats in the
wild and showed no evidence of specialized
behavior in cooperative activities based on sex
and/or age. However, other researchers have
found that nutritional status from foraging does
influence which individual is on standing guard
duty and for how long (Cant and Field, 2001
Clutton-Brock et al., 1999, 2003) I hypothesized
that when meerkats are in controlled populations
(zoological park) where foraging does not
dominate the majority of their time and
nutritional status is constant, they will take on
specialized roles to better contribute to the
vitality of the mob. If meerkats do in fact take
on a specialized role in social behaviors, then
it should be evident in the standing guard duty
because they are all in the same nutritional
state.

Figure 4. Female meerkat on standing guard at
Cheyenne Mountain Zoo, Colorado Springs, CO.
2006. Photo by Jason Gue

a)


b)

Figure 2. Comparison of standing guard conducted
by dominant pair and subordinates (18
individuals t -3.6, p 0.001, Independent
t-test, standard error is shown)
Figure 8. Male meerkat on standing guard at
Cheyenne Mountain Zoo, Colorado Springs, CO.
2006, Photo by Jason Gue
Figure 5. Average time daily (min) that males and
females conducted standing guard within their
litter designation. The dominant male and
females were not factored in. Litters 1, 2 and 3
had no males because they have been removed
because of behavior. Litter 4 was a single male
birth with no females. Litter 1 conducted
standing guard significantly more than litter 6
(p 0.0). Litter 2 stood guard significantly
more over litter 3 (p 0.012), litter 6 (p
0.0) and was marginally less significant than
litter 5 (p .058). Litter 3 conducted standing
guard significantly less than litter 2 (p
0.012) and litter 4 (p 0.003). Litter 4
conducted standing guard significantly more that
litter 3 (p 0.003) and litter 6 (p 0.0) while
significantly less than litter 5 (p 0.024).
Litter 5 conducted standing guard significantly
more then litter 4 (p 0.024), litter 6 (p
0.0), and had marginal significance over litter 2
(p 0.058). Litter 6 was significantly less
than litter 1, 2, 4, 5 (p 0.0). (n 702
occurrences of standing guard F 24.0, p 0.0
using a one-way ANOVA with Tukeys post hoc test,
standard error is shown)
c)

REFERENCES Bednekoff, P.A. 1997. Mutualism
among safe, selfish sentinels a dynamic game.
American Naturalist. Vol. 150. 3373-392
Bekoff, M. 1979. Behavioral acts description,
classification, ethogram analysis, and
measurement.  Pgs. 67-80, in The analysis of
social interactions methods, issues, and
illustrations (edited by R. C. Cairns). Lawrence
Erlbaum Associates, Hillsdale, New
Jersey. Cant, M.A. and J. Field. 2001. Helping
effort and future fitness in cooperative animal
societies. Proceedings of the Royal Society
of London, Series B, 2681959-1964. Clutton-Brock,
T.H., D. Gaynor, R. Kansky, A.D.C. MacColl, G.
McIlrath, P. Chadwick, P.N.M. Brotherton, J.M.
ORiain, M. Manser and J.D. Skinner. 1998.
Cost of cooperative behaviour in suricates
(Suricata suricatta). Proceedings of the
Royal Society of London, Series B,
265185-190. Clutton-Brock, T.H., M.J. ORiain,
P.N.M. Brotherton, D. Gaynor, R. Kansky, A.S.
Griffin and M. Manser. 1999. Selfish
sentinels in cooperative mammals. Science.
2841640-1644. Clutton-Brock, T.H., A.F. Russell,
L.L. Sharp, A.J. Young, Z. Balmforth and G.M.
McIlrath. 2002. Evolution and development
of sex differences in cooperative behavior in
meerkats. Science. 297253-256. Clutton-Brock,
T.H., A.F. Russell and L.L. Sharpe. 2003.
Meerkat helpers do not specialize in particular
activities. Animal Behaviour. 66531-540.
Macdonald, D.W. 1986. A meerkat volunteers for
guard duty so its comrades can live in peace.
Smithsonian. 1755- 64. Russell, A.F., T.H.
Clutton-Brock, P.N.M. Brotherton, L.L. Sharpe,
G.M. McIlrath, F.D. Dalerum, E.Z. Cameron and
J.A. Bernard. 2002. Factors affecting pup
growth and survival in co-operatively breeding
meerkats Suricata suricatta. Journal of
Animal Ecology. 71700-709 Sharpe, L.L. and M.I.
Cherry. 2003. Social play does not reduce
aggression in wild meerkats. Animal Behaviour.
66989-997
Figure 1. Male meerkat at Cheyenne Mountain Zoo,
Colorado Springs, CO. Photo by Jenyva Turner

STUDY OBJECTIVES (1) Do captive male or female
meerkats conduct standing guard duty at a higher
rate? (2) In captivity is the dominant male or
female conducting standing guard at a higher rate
than the subordinates? (3) In captivity does
different litter groups stand guard more than
others? (4) Does time of day impact which
meerkat is on standing guard in captivity?
Figure 7. Comparison of gender by the average
time of day that standing guard was observed.
All 20 meerkat (15 females, 5 males) had equal
opportunity of conducting standing guard during
all three observation periods. a) Shows the
0700-0900h watch period b) is for the 1100-1300h
watch period, c) is for the 1600-1800h watch
period. The interaction between time of day and
gender was insignificant (F 1.16, p 0.32,
2-way 3x2 mixed ANOVA, standard error is shown).
Figure 3. The average time per day individual
meerkats spent on standing guard based on gender.
All males (5) and females (15) were accounted
for regardless of dominance. (n 702
occurrences of standing guard during study F
8.61, p 0.003 using a one-way ANOVA with Tukey
post hoc test, standard error is show)

ACKNOWLEDGMENTS I would like to thank the Fort
Lewis College, Department of Biology, especially
Dr. Julie Korb and Dr. Joseph Ortega for
assisting in research design, suggestions, and
comments on my manuscript. This project would
not have been possible if it were not for
Cheyenne Mountain Zoo, especially, Jenyva Turner,
Andie Armbrust, RoxAnna Breitigan, Randy Barker,
Dr. Michelle Bowman and Tracy Leeds for allowing
me to conduct the study, assisting in marking the
meerkats, and letting me work out of the African
Rift Valley between observation periods. I would
also like to thank Dr. Sue Kraus, Dr. Beverly
Chew and Katie Moorstein for donating their time,
insight and materials for conducting the
statistical analysis. Finally, I would like to
thank the meerkats that make their home at
Cheyenne Mountain Zoo for being good sports with
their unique hair cuts and minimal biting.
EXPERIMENTAL DESIGN AND METHODS The meerkat mob
was grouped by litter to help determine whether
their social behaviors are generalized or
specialized within the mob. There was a total of
20 meerkats, that were grouped by dominant pair
and litters 1 through 6. Each meerkat was given
a unique hair cut to insure correct
identification during the study period.
Observations were conducted at 0700h-0900h,
1100h-1300h, and 1600h-1800h for 39 consecutive
days. I have selected these times based upon
peak times that meerkats are outside their
burrows in a natural setting and zoo operation
hours to minimize zoo keeper and general public
interference with the meerkats behavior
(Clutton-Bock et al., 1999 Russell et al., 2002
Sharp and Cherry, 2002). The method of
observation I used for this study was sampling of
all occurrences (Bekoff, 1979).
Figure 6. Average time on standing guard by time
of day and litter with dominant pair included.
The interaction between the different times of
day and the average amount of time each litter
including the dominant pair was significant (F
5.8, p 0.004, 2-way 3x7 mixed ANOVA, standard
error is shown)