Page 46 - Zoo Animal Learning and Training

18 2 The Cognitive Abilities of Wild Animals

VetBooks.ir reinforcement that would be likely to occur intrasexual competitions by bighorn sheep
do not always result in a won contest for that
in free‐roaming animals, it can sometimes be
difficult to determine whether a behaviour is
increasing due to positive reinforcement or individual animal.
negative reinforcement. If we observe a griz- 2.2.2 Punishment
zly bear swimming in a river on a hot sum-
mer day, one might wonder whether the bear Just like both positive and negative rein-
is swimming because the behaviour (i.e. forcement, animals experience punishment
swimming) is providing coolness or opportu- in many situations in their natural environ-
nities for foraging (and is thus positively ment. Within social groups of primates, for
reinforcing) or because the behaviour is example, subordinate animals who attempt
resulting in the removal of discomfort from to access preferred resources (e.g. food,
overheating (and thus negatively reinforc- reproduction with potential mates) may
ing)? In a mobbing situation, do European often be punished by dominant members of
bee‐eaters exhibit aggression toward snakes the group. Another example can be thought
because mobbing results in the removal of in terms of mobbing – an antipredator
of an aversive predator near their eggs (i.e. behaviour – in birds toward other avian
negatively reinforcing) or because mobbing predators. The function of mobbing behav-
provides increased opportunities for social iour is described as a means to bring
cohesion among bee‐eaters or a higher num- together conspecifics – usually within a
ber of intact eggs (i.e. positively reinforcing). social group – to remove intruders (Caro
Although these are empirical questions that 2005). A hawk or eagle that is mobbed by a
require further scientific study to tease apart, flock of crows might be less likely to visit
it is nonetheless interesting to consider exactly that spot because it resulted in the aversive
what processes are contributing to the learn- consequence of being attacked by multiple
ing history that modifies an individual’s blackbirds simultaneously (i.e. positive pun-
behaviour over its lifetime. ishment) or losing a preferred food item in
In addition to different types of reinforce- the process (i.e. negative punishment).
ment, the schedule at which an animal may Individuals who leave a food source
obtain reinforcers in the wild varies tremen- unguarded without caching or storing their
dously. Broadly speaking, animals may obtain food, may find that as a consequence, other
reinforcers continuously or intermittently. individuals – either from within or outside a
An animal that is receiving continuous rein- social unit – can run off with these resources.
forcement for a behaviour is obtaining rein- This would be a form of negative punish-
forcement every time it exhibits that ment, in which the removal of appetitive
behaviour, whereas behaviours that are inter- stimuli (i.e. resources) can follow from
mittently reinforced are not reinforced every overly aggressive or passive behaviour.
time. Interestingly, behaviours that are not Scientific evidence of negative punishment
reinforced every time are actually more likely is much less prevalent than positive punish-
to persist longer in the absence of reinforce- ment in wild animals. However, there are
ment than behaviours that are reinforced some extreme examples that can be seen in
every time. As you might suspect, most cases of infant mortality and disappearances
behaviours that an individual animal exhibits in male takeovers in free‐ranging howling
in the wild are intermittently reinforced. For monkeys (Alouatta palliata) in Costa Rica
example, stalking or hunting by a male jaguar (Clarke 1983), a species in which dominant
does not always result in successfully taking males have exclusive access to mate with
down prey, male peacocks that engage in receptive and high‐estrous females. Thus,
sexual displays in soliciting for a potential punishment contingencies, although not
mate do not always achieve copulation, and strictly programmed as in a captive setting,