Abstract: In many of the studies reviewed in this book, eavesdropping takes the
following form: a subject has the opportunity to monitor, or eavesdrop upon, an
interaction between two other animals,Aand B. The subject then uses the information
obtained through these observations to assess A`s and B`s relative dominance
or attractiveness as a mate (e.g. Mennill et al., 2002; Ch. 2). For example, Oliveira
et al. (1998) found that male fighting fish Betta splendens that had witnessed two
other males involved in an aggressive interaction subsequently responded more
strongly to the loser of that interaction than the winner. Subjects-behaviour could
not have been influenced by any inherent differences between the two males, because
subjects responded equally strongly to the winner and the loser of competitive
interactions they had not observed. Similarly, Peake et al. (2001) presented
male great tits Parus major with the opportunity to monitor an apparent competitive
interaction between two strangers by simulating a singing contest using two
loudspeakers. The relative timing of the singing bouts (as measured by the degree
of overlap between the two songs) provided information about each “contestants”
relative status. Following the singing interaction, one of the “contestants” was
introduced into the male`s territory. Males responded significantly less strongly
to singers that had apparently just “lost” the interaction (see also McGregor &
Dabelsteen, 1996; Naguib et al., 1999; Ch. 2).
What information does an individual acquire when it eavesdrops on others?
In theory, an eavesdropper could acquire information of many different sorts:
about A, about B, about the relationship between A and B, or about the place of
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A`s and B`s relationship in a larger social framework. The exact information acquired
will probably reflect the particular species social structure. For example,
songbirds like great tits live in communities in which six or seven neighbours
surround each territory-holding male. Males appear to benefit from the knowledge
that certain individuals occupy specific areas (e.g. Brooks & Falls, 1975), that
competitive interactions between two different neighbours have particular outcomes,
and that these outcomes are stable over time. We would, therefore, expect
an eavesdropping great tit not only to learn that neighbour A was dominant to
neighbour B, for example, but also to form the expectation that A was likely to
defeat B in all future encounters. More speculatively, because the outcome of territorial
interactions are often site specific (reviewed by Bradbury & Vehrencamp,
1998), we would expect eavesdropping tits to learn further that A dominates B
in some areas but B dominates A in others. In contrast, the information gained
from monitoring neighbours interactions would unlikely be sufficient to allow
the eavesdropper to rank all of its neighbours in a linear dominance hierarchy,
because not all neighbouring males would come into contact with one another.
Such information would be difficult if not impossible to acquire; it might also be
of little functional value.
In contrast, species that live in large, permanent social groups have a much
greater opportunity to monitor the social interactions of many different individuals
simultaneously. Monkey species such as baboons Papio cynocephalus, for
example, typically live in groups of 80 or more individuals, which include several
matrilineal families arranged in a stable, linear dominance rank order (Silk et al.,
1999). Offspring assume ranks similar to those of their mothers, and females maintain
close bonds with their matrilineal kin throughout their lives. Cutting across
these stable long-term relationships based on rank and kinship are more transient
bonds: for example, the temporary associations formed between unrelated
females whose infants are of similar ages, and the “friendships” formed between
adult males and lactating females as an apparent adaptation against infanticide
(Palombit et al., 1997, 2001). In order to compete successfully within such groups, it
would seem advantageous for individuals to recognize who outranks whom, who
is closely bonded to whom, and who is likely to be allied to whom (Harcourt, 1988,
1992; Cheney & Seyfarth, 1990; see below). The ability to adopt a third party`s perspective
and discriminate among the social relationships that exist among others
would seem to be of great selective benefit.
In this chapter, we review evidence for eavesdropping in selected primate
species and we consider what sort of information is acquired when one individual
observes or listens in on the interactions of others. We then compare eavesdropping
by primates with eavesdropping in other animal species, focusing on both
potential differences and directions for further research

Abstract: Many bursate nematodes are of major importance to animal health. Animals are often parasitized by multiple species that differ in their prevalence, relative abundance and/or pathogenicity. Implementation of effective management strategies for these parasites requires reliable methods for their detection in hosts, identification to the species level and measurement of intensity of infection. One major problem is the difficulty of accurately identifying and distinguishing many species of bursate nematode because of the remarkable morphological similarity of their eggs and larvae. The inability to identify, with confidence, individual nematodes (irrespective of their life-cycle stage) to the species level by morphological methods has often led to a search for species-specific genetic markers. Studies over the past 15 years have shown that sequences of the internal transcribed spacers of ribosomal DNA provide useful genetic markers, providing the basis for the development of PCR-based diagnostic tools. Such molecular methods represent powerful tools for studying the systematics, epidemiology and ecology of bursate nematodes and, importantly, for the specific diagnosis of infections in animals and humans, thus contributing to improved control and prevention strategies for these parasites.

Abstract: Historically, pet dogs were trained using mainly negative reinforcement or punishment, but positive reinforcement using rewards has recently become more popular. The methods used may have different impacts on the dogsâ&#65533;&#65533; welfare. We distributed a questionnaire to 364 dog owners in order to examine the relative effectiveness of different training methods and their effects upon a pet dogâ&#65533;&#65533;s behaviour. When asked how they trained their dog on seven basic tasks, 66% reported using vocal punishment, 12% used physical punishment, 60% praise (social reward), 51% food rewards and 11% play. The ownerâ&#65533;&#65533;s ratings for their dogâ&#65533;&#65533;s obedience during eight tasks correlated positively with the number of tasks which they trained using rewards (P<0.01), but not using punishment (P=0.5). When asked whether their dog exhibited any of 16 common problematic behaviours, the number of problems reported by the owners correlated with the number of tasks for which their dog was trained using punishment (P<0.001), but not using rewards (P=0.17). Exhibition of problematic behaviours may be indicative of compromised welfare, because such behaviours can be caused byor result ina state of anxiety and may lead to a dog being relinquished or abandoned. Because punishment was associated with an increased incidence of problematic behaviours, we conclude that it may represent a welfare concern without concurrent benefits in obedience. We suggest that positive training methods may be more useful to the pet-owning community.

Abstract: The songbird auditory system is an excellent model for neuroethological studies of the mechanisms that govern the perception and cognition of natural stimuli (i.e., song), and the translation of corresponding representations into natural behaviors. One common songbird behavior is the learned recognition of individual conspecific songs. This chapter summarizes the research effort to identify the brain regions and mechanisms mediating individual song recognition in European starlings, a species of songbird. The results of laboratory behavioral studies are reviewed, which show that when adult starlings learn to recognize other individual's songs, they do so by memorizing large sets of song elements, called motifs. Recent data from single neurons in the caudal medial portion of the mesopallium are then reviewed, showing that song recognition learning leads to explicit representation of acoustic features that correspond closely to specific motifs, but only to motifs in the songs that birds have learned to recognize. This suggests that the strength and tuning of high-level auditory object representations, of the sort that presumably underlie many forms of vocal communication, are shaped by each animal's unique experience.