Page 136 - Zoo Animal Learning and Training

108 6 Environmental Enrichment: Opportunities for Learning

Auditory stimuli often in the form of con-
VetBooks.ir specific vocalisations have been used in envi- speech. It has been suggested that music for
animals should be based on the species’
ronmental enrichment studies (Rukstalis and
was carried out on primates, showed they
French 2005; Simonet et al. 2005; Kelling vocalisation structures. A study where this
et al. 2012). However, if such calls are used paid more attention to the ‘monkey music’
frequently with no contingency to the behav- than to human music (Snowdon and Teie
ioural response, then animals will learn to 2013). The same was found by Snowdon et al.
habituate to such calls, change its behaviour (2015) for domestic cats.
or even be stressed by the calls (Harris and The use of olfactory enrichment has
Haskell 2013; Massen et al. 2014). For exam- increased in recent times, despite the fact
ple, predator warning calls, which are emit- that humans have relatively poor olfactory
ted without showing an appropriate predator abilities (Clark and King 2008; Laska 2017).
model, may soon lose their ability to modify But as with other sensory stimuli it is impor-
animal behaviour (Griffin et al. 2000), but tant that either there is some natural contin-
some species can retain the capacity of pred- gency between the stimulus presented and
ator call recognition over evolutionary time consequences for the animals (e.g. arrival of
(Hettena et al. 2014). The use of such calls as food or a model predator) or that each stimu-
environmental enrichment is considered by lus is used infrequently. Predator scents have
some organisations as questionable in terms been shown to be effective in eliciting anti-
of their impact on animal welfare, since they predatory responses in many prey species
provoke an antipredatory response and pred- without the need for the appearance of a
ators are a source of stress. predator model (Apfelbach et al. 2005; Rosell
In many species, such as birds, juveniles et al. 2013). For example, the smell of a jaguar
learn their species‐specific vocalisations on llama wool is sufficient for giant anteaters
from listening to other members of their to start rushing around their enclosure in an
social group and need to practice these escape response (Orlando and Fernández
vocalisations for them to be perfected (Payne 2014). But of course such stimuli must be
et al. 2000; Catchpole and Slater 2008). applied sparingly, for a short period of time
Furthermore, many vocalisations will only be (a few minutes only) and in a manner that the
expressed once the appropriate stimulus has stimulus can be fully removed from the ani-
been presented such as the sight of a preda- mal’s enclosure. If this stimulus is prolonged,
tor or the territorial vocalisation of a conspe- it could distress the animals since they would
cific (Hollén and Radford 2009). Territorial not be able to flee from the supposed preda-
vocalisations were once popularly used as tor, decreasing their welfare.
auditory environmental enrichment for spe- Other scents that can be used to enrich the
cies such as gibbons who would respond to lives of captive animals are scents used to
them with their own territorial call mark the boundaries of territories, such as
(Shepherdson et al. 1999). Beyond the vocal those used by big cats or primates such as
response, animals subjected to such territo- lemurs. The careful placing of such scents at
rial challenges often show enhanced social the edges of an enclosure will teach an animal
behaviour and potentially have stronger about the limits of its territory (Campbell‐
social bonds. Palmer and Rosell 2010; Jackson et al. 2012).
Finally in terms of auditory enrichment the In captivity, it is important that scent marking
use of music as a stimulus has been popular is not constantly removed during the cleaning
ever since studies showed that cows listening process because in species, which counter-
to classical music or calf vocalisations pro- mark (mark over other individual’s scents)
duced more milk (McCowan et al. 2002; this could be perceived as another individual
O’Brien 2014). The structure of music for invading their territory causing significant
humans is related to the structure of human stress to the enclosure’s occupant.