Biomedical Engineering Reference
In-Depth Information
well-being (
Novak and Suomi, 1988; Overall and Dyer,
2005
).
Behavioral management can work in concert with
research protocols directly to reduce stress and can improve
the research model. For example, primates are sometimes
restrained in primate chairs for certain research protocols in
which animals must remain still for extended periods of
time. Subjects typically wear a specialized collar that
attaches to the restraint device and limits head movement.
The chairs may also have restraints that limit movement of
arms or legs. This kind of restraint is stressful for many
subjects and can lead to agitation and frustration (
Ruys
et al., 2004
), particularly initially. Behavioral management
techniques can help reduce the stress associated with this
restraint.
McGuffey et al. (2002)
found that providing
monkeys with unstructured play time in an activity cage
reduced their anxiety toward the restraint chair. Further,
training monkeys to sit in the primate chair using an
approach that emphasizes positive reinforcement training
(see the section “Positive Reinforcement Training” below)
can reduce stress associated with the chair and can increase
the ease of these kinds of research procedures (
Rennie and
Buchanan-Smith, 2006b
). Other ways in which behavioral
management techniques can improve the scientific
endeavor will be discussed throughout the chapter.
groups. Much of this behavioral management is focused on
providing caged primates with social opportunities,
including pair housing. There has been considerable
improvement in the past ten years in the types of caging
available for social enrichment, including a variety of
panels that allow social access to partners (see Chapter 9 for
more details). Caging options currently exist that allow
small groups of primates to live together (e.g.
Erwin and
Landon, 1992; Weed et al., 1995
). Animals in cages are also
typically provided with: (1) an enhanced schedule of
feeding enrichment; (2) a variety of toys; (3) additional
stimulation from music (in some facilities); (4) videotapes
of various types; (5) the use of destructible enrichment
(e.g. paper, boxes); and (6) additional positive interaction
with humans to compensate for the lack of social partners.
Whereas NHPs housed in groups are less likely than
those in cages to show behavioral problems (
Schapiro et al.,
1996a,b
), other issues associated with this type of housing
can lead to diminished well-being and therefore must be
considered. Aggression and social dynamics can negatively
affect some individuals (
Oates-O'Brien et al., 2010
). It is
useful and often imperative to know which animals rank at
the top of the dominance hierarchy. For example, removal
of the dominant female from a rhesus macaque group can
lead to an increase in aggression in the group (
Oates-
O'Brien et al., 2010
). Maternal behavior may also be
problematic in captive primate groups. Primiparous rhesus
macaque mothers are more likely than multiparous mothers
to neglect or abuse their infants (
McCormack et al., 2006
),
and infants are occasionally stolen by females other than
the dam, requiring increased levels of observational vigi-
lance by management staff during the birth season. In
general, the ratio of enrichment personnel to animals is
lower (i.e. fewer enrichment staff per NHP) for facilities
that have a large number of group-housed primates than for
facilities that house NHPs primarily in cages (
Baker et al.,
2007
). However, there is a great need for personnel trained
in primate behavior to observe group dynamics and monitor
group stability.
MANAGING BEHAVIOR
Colony Composition
While the ultimate goals of behavioral management plans
are the same regardless of the species or size of the colony,
in practice these plans have to take the size, composition,
and purpose (e.g. research or breeding) of the colony into
account. There are different challenges associated with
animals housed in large, outdoor groups than there are with
animals housed in small, indoor cages. NHPs in cages are
often on active research protocols, whereas those in large
groups are often part of the breeding population. Although
animals in large breeding groups may be subjects in
behavioral studies, they are less frequently involved in
invasive protocols. Animals may also be kept in small
indoor or outdoor groups, either as study animals or
breeders.
Caged animals typically experience more threats to
their psychological well-being than do those housed in
large groups. Caged primates have less space, less social
interaction, and are more likely to be involved in stressful
research procedures than are those housed in large groups.
Caged primates are at greater risk for developing behav-
ioral problems than are primates in groups (see “Under-
standing Natural Behavior” below). Because of these
heightened risks, behavioral management effort is often
greater for caged primates than for those living in large
Understanding Natural Behavior
In order for enrichment and the broader behavioral
management program to be effective, these need to be
tailored to the individual species of NHP (
Lutz and Novak,
2005; Jennings et al., 2009; National Research Council,
2011
). Thus, knowledge of the normal behavioral repertoire
of the species is essential for the development of an
appropriate behavioral management plan. While certain
behaviors, such as locomotion and climbing, are relatively
ubiquitous across the various taxonomic groups of
primates, others are not. Owl monkeys use nesting cavities
and should be provided with the ability to nest. Some
prosimian (Strepsirhine) and New World Monkey species
