Page 232 - Zoo Animal Learning and Training

204 Box B5 ognitive Abilities oo Marine Mammals

VetBooks.ir whales, the odontocetes, have minimal or no to signs when the only stimuli observable on
the screen are bright balls against a black
sense of smell, an important path to cogni-
tion in terrestrial mammals (e.g. Otto and
nals (Herman et al. 1990) and can mimic
Eichenbaum 1992), whilst the presence of background tracking the pattern of hand sig-
innervated taste buds and results of psycho- behaviours viewed on a video monitor
physical testing suggest that dolphins may (Herman et al. 1993; Pack 2015).
have a satisfactory sensitivity for some com- Dolphins have excellent mimetic skills in
pounds, including citric acid (sour), quinine both behavioural and vocal domains, an unu-
sulphate (bitter), and sodium chloride (salty) sual ability amongst mammals outside of
(Kusnetsov 1990; Nachtigall and Hall 1984). humans, although also seen in some birds.
The baleen whales have better developed Dolphins imitate other dolphin phonations,
olfactory bulbs but as yet little is known trainer whistles, and computer‐generated
about their chemical detection capabilities sounds (Richards et al. 1984). They mimic
(Pihlström 2008). the behaviour of conspecifics and other spe-
Dolphins have demonstrated the ability to cies such as humans and seals. They mimic
categorise objects in same/different and behaviour and sounds spontaneously as well
match‐to‐sample paradigms. They can develop as under stimulus control by a trainer
learning sets for acoustic stimuli, measured by (Herman 2002).
second trial performance on two choice dis- Bottlenose and rough‐toothed dolphins
criminations, with appropriate training (Steno bredanensis) innovate by responding
(Herman 1980). They form representations of correctly to commands to produce new
objects, not just their perceptual characteris- behaviours (Pryor et al. 1969). This ability
tics. Object representation is illustrated by has been cleverly used in conjunction with
excellent cross‐modal matching abilities, for imitation to demonstrate the ability to syn-
example, in which dolphins discriminate chronously perform an innovated behaviour
objects presented visually using a different with another dolphin (Herman 2002).
modality, echolocation, and vice versa (Harley Furthermore, when embedded in a set of
et al. 1996, 2003; Pack et al. 2004). diverse commands a dolphin can accurately
Dolphins can respond appropriately to do a directed behaviour, imitate the behav-
chains of commands delivered by arm ges- iour of another dolphin, or perform a behav-
tures or acoustic signals representing objects, iour that it had executed in a previous trial
actions, or modifiers to guide behaviour. For (Mercado et al. 1999). The last ability indi-
example, ‘surface‐pipe‐fetch‐bottom‐hoop’, cates memory for specific past actions.
led the dolphin to take the pipe on the sur- A dolphin can initiate and respond to
face of the water to a hoop on the bottom of pointing gestures (Xitco et al. 2004) and
the tank when there were a variety of other identify objects by eavesdropping on the
objects in diverse locations (Herman 1986). echolocation of another dolphin (Xitco and
Although there is some controversy over Roitblat 1996). The ability to mimic behav-
whether to describe this behaviour as under- iour, initiate and respond to pointing, and
standing language, demonstrating semantic eavesdrop all suggest ways that dolphins can
and syntactic abilities, or more basic rule share information about their environments
learning, the fact is that the resulting behav- with conspecifics. They can also use tools for
iour is complex (Herman 1988, 1989; foraging in natural environments (e.g. sponge
Schusterman and Gisiner 1988, 1989). fishing) (Mann et al. 2008; Smolker et al.
Dolphins can be observed responding to 1997) and solve problems to gain food
hand signals in commercial aquaria, as well rewards using tools in captive settings. For
as in scientific studies, but they can also example, Gory (reviewed in Kuczaj and
respond to signals delivered on TV or video Walker 2006) reported that dolphins learned
monitors. They can even respond correctly observationally to drop four weights (tools)