Abstract: Eavesdropping can be defined as the extraction of information from the interactions between other individuals. It provides a relatively cheap way of gathering relevant information for fitness enhancement. Here, we propose that obligate avian brood parasites, which always lay their eggs in foreign nests of individuals of other species, may eavesdrop on their host sexual signals to locate nests of high quality individuals in which to lay their parasitic eggs. Sexual signal variation can honestly signal parental quality. Thus, by eavesdropping on sexual signals, parasites may select high quality foster parents for their own offspring. Such a use of sexual signals within host populations by brood parasites differs from signal exploitation theory that proposes that parasite only use signals to locate potential host independently from signaller quality. Here, we review the avian literature concerning host choice within a host species by obligate avian brood parasites and find evidence for host selection within individuals of a host species on the basis of cues potentially functioning as sexually selected traits, or at least revealing parental abilities. We have also found support for the existence of benefits linked to host selection by avian brood parasites. Finally, one study reported on the attenuation of a sexual ornament in host populations under strong pressure by brood parasites. Most of these findings have been interpreted as evidence for host selection by avian brood parasites based on the conspicuousness of sexual signals. We suggest, however, that these findings may in fact reveal eavesdropping on host signalling performance by brood parasites which would use the information extracted to choose the better individuals among conspecifics of a given host. This provides a new perspective for the study of host selection in obligate brood parasites, and raises interesting questions for the study of animal cognition that would deserve experimental studies.

Abstract: Abstract In several studies of social monitoring in primates, subordinate animals directed more visual attention toward dominant animals than vice versa. This behavior is thought to enable subordinate animals to avoid conflict. We sought to clarify whether visual attention behavior functions in this manner in a small captive group of brown capuchin monkeys, Cebus apella. We tested the hypothesis that social monitoring is related to dominance status. Dominance status was determined based on the directionality of aggressive behavior, and visual attention was quantified by using focal animal sampling. Subordinate animals directed significantly more visual attention toward others than dominant animals. Subordinate animals also looked more frequently at the animals that attacked them and others the most. The results indicate that social monitoring behavior in this captive group was driven by conflict-avoidance.

Abstract: At the beginning of the twentieth century, behaviourists like John B. Watson (1878-1958) changed the focus of attention from the inside of the brain (mentalism and introspection then being the main trend in psychology at the time) to the outside (Watson, 1913). They believed that we could learn nearly everything about animals and humans by studying their performance in learning experiments, and this was both measurable and verifiable. Today in the first decade of the twenty-first century, there has been a return to the inside. The neurosciences seek physiological explanations and connections between external behaviour and the neural mechanisms within the nervous system. With the revolution in magnetic resonance imaging (MRI) technology researchers are now able to visually represent neural activity. Other researchers have developed mathematical models and programs to visualise the patterns created in the periphery prior to central integration The author in this paper would like to distinguish these descriptive forms of representation from actual representations, i.e., those of which the animal is actually aware or conscious. Why does an animal sometimes make perceptual mistakes? (Case Study I “The Turtle and the Plastic Bag”). Is there more to dispositions? (Case Study II: “Taking Representation for a Walk. Argos and the Fake Daniel Dennett”). How is prey represented to an animal? (Case Study III “Representation of Prey in the Jellyfish/Herring Predator-Prey Dyad”). Does a simple animal feel pain or suffer? (Case Study IV: A Can of Worms. The Earthworm as Bait) It will be argued on the basis of contemporary biosemiotic research that animals (including both vertebrates and invertebrates) represent environmental information internally, and these representations can be subdivided into i.) primary or peripheral representation and ii.) central representation which are quantitative and qualitative respectively. Sensory information is conveyed via signals, these are received as stimuli then transduced into internal signals (see Theoretical Framework). At this stage the animal is not aware of the quality of the information as it has not yet been integrated or processed in a ganglionic complex. One can describe the properties of this pre-integrated information as quantitative and syntactical i.e., spatial and temporal ordering of incoming signals and their relations. The sign which is the smallest unit of qualitative representation arises only after integration of information from two or more discrete sensory modalities. These findings have repercussions for current models of animal learning and behaviour, especially in lower invertebrates (the principal subject of this paper); they also challenge the development of robots based on so-called simple systems

Abstract: Abstract  Encounters between groups of wild chacma baboons (Papio ursinus) can be viewed as a natural experiment to investigate the nature of these primates mental representations of large-scale space. During a 16-month field study in a high population density habitat we recorded the foraging routes and the most important resources of a group of 25 individuals. Also, we estimated the locations of additional baboon groups relative to the study group. Routes were less linear, travel speed was higher, and inter-resource distances were larger when other groups were present within 500 m of the focal group; thus, the study group avoided others by taking detours. We predicted that evasive manoeuvres would be characteristic of different possible orientation mechanisms, and compared them with our observations. We analysed 34 evasive manoeuvres in detail. In an area that lacked prominent landmarks, detours were small; larger detours occurred when resources were directly visible, or in the vicinity of a hill offering conspicuous landmarks. In areas without prominent landmarks, detours were along familiar routes and waiting bouts of up to 60 min occurred; on one occasion the study group aborted their entire day`s journey. We discuss these findings in the light of time and energy costs and suggest that the baboons lack the ability to compute Euclidean relations among locations, but use network maps to find their way to out-of-sight locations.

Abstract: We investigated 71 horses at five stud farms. Their breeds were Thoroughbred (n = 48), Anglo-Arab (n = 7), Thoroughbred mixed breed (n = 5), Appaloosa (n = 3), Selle Francais (n = 2), Dutch Warmblood, Haflinger, Pinto, Quarter Horse and Westfalen (n = 1, respectively), and one horse's breed was not known, but was a heavy horse. Their genders were stallion (n = 5), gelding (n = 41) and female (n = 25). Their ages ranged from 4 to 24 and the average was 11.1 +/- 5.3 (S.D.). The horses' behaviour was twice observed for 2 h both before and after feeding, using a scan sampling technique at 2 min intervals. We investigated the relationship between management factors, age, sex, breed and behavioural patterns of stabled horses, and the occurrence of weaving by a least-squares analysis of variance, a correlation analysis, Chi-square test and an analysis of behavioural sequences. Thoroughbred horses displayed weaving more than other breeds (P < 0.01) and horses in box stalls which were face to face with each other displayed weaving more than those in box stalls which were formed in a line (P < 0.01). The time budget of weaving correlated negatively with the amount of hay-cube fed (kg/day) (P < 0.05) and time budgets of drinking, bedding investigation, looking and coprophagia (P < 0.01, respectively). From the analysis of behavioural sequences, weaving followed resting (P < 0.01), looking (P < 0.01) and pawing (P < 0.05), and was followed by them (P < 0.01, P < 0.01 and P < 0.05, respectively). The least-squares analysis of variance revealed that Thoroughbred horses investigated the bedding more than other breeds (P < 0.05), horses that are usually in contact with `mainly familiar people' investigated the bedding significantly less than those usually in contact with `people including strangers' (P < 0.05), and horses in box stalls which were face to face with each other tended to investigate the bedding more than those in box stalls which were formed in a line. The time spent feeding was related to food type (min/kg), and tended to be negatively correlated with the time budget of bedding investigation behaviour. These results indicate that weaving in horses is affected by breed, stable design, feed type, and other behavioural traits.