Rochais, C., Henry, S., Fureix, C., & Hausberger, M. (2016). Investigating attentional processes in depressive-like domestic horses (Equus caballus). Behavioural Processes, 124, 93–96.
Abstract: Abstract Some captive/domestic animals respond to confinement by becoming inactive and unresponsive to external stimuli. Human inactivity is one of the behavioural markers of clinical depression, a mental disorder diagnosed by the co-occurrence of symptoms including deficit in selective attention. Some riding horses display ‘withdrawn’ states of inactivity and low responsiveness to stimuli that resemble the reduced engagement with their environment of some depressed patients. We hypothesized that ‘withdrawn’ horses experience a depressive-like state and evaluated their level of attention by confronting them with auditory stimuli. Five novel auditory stimuli were broadcasted to 27 horses, including 12 ‘withdrawn’ horses, for 5 days. The horses’ reactions and durations of attention were recorded. Non-withdrawn horses reacted more and their attention lasted longer than that of withdrawn horses on the first day, but their durations of attention decreased over days, but those of withdrawn horses remained stable. These results suggest that the withdrawn horses’ selective attention is altered, adding to already evidenced common features between this horses’ state and human depression.
|
Krueger, K., Flauger, B., Farmer, K., & Hemelrijk, C. (2014). Movement initiation in groups of feral horses. Behav. Process., 103, 91–101.
Abstract: Abstract Herds of ungulates, flocks of birds, swarms of insects and schools of fish move in coordinated groups. Computer models show that only one or very few animals are needed to initiate and direct movement. To investigate initiation mechanisms further, we studied two ways in which movement can be initiated in feral horses: herding, and departure from the group. We examined traits affecting the likelihood of a horse initiating movement i.e. social rank, affiliative relationships, spatial position, and social network. We also investigated whether group members join a movement in dominance rank order. Our results show that whereas herding is exclusive to alpha males, any group member may initiate movement by departure. Social bonds, the number of animals interacted with, and the spatial position were not significantly associated with movement initiation. We did not find movement initiation by departure to be exclusive to any type of individual. Instead we find evidence for a limited form of distributed leadership, with higher ranking animals being followed more often.
|
Zentall, T. R. (2006). Timing, memory for intervals, and memory for untimed stimuli: The role of instructional ambiguity. Behav. Process., 71(2-3), 88–97.
Abstract: Theories of animal timing have had to account for findings that the memory for the duration of a timed interval appears to be dramatically shorted within a short time of its termination. This finding has led to the subjective shortening hypothesis and it has been proposed to account for the poor memory that animals appear to have for the initial portion of a timed interval when a gap is inserted in the to-be-timed signal. It has also been proposed to account for the poor memory for a relatively long interval that has been discriminated from a shorter interval. I suggest here a simpler account in which ambiguity between the gap or retention interval and the intertrial interval results in resetting the clock, rather than forgetting the interval. The ambiguity hypothesis, together with a signal salience mechanism that determines how quickly the clock is reset at the start of the intertrial interval can account for the results of the reported timing experiments that have used the peak procedure. Furthermore, instructional ambiguity rather than memory loss may account for the results of many animal memory experiments that do not involve memory for time.
|
Schmidt, J., Scheid, C., Kotrschal, K., Bugnyar, T., & Schloegl, C. (2011). Gaze direction – A cue for hidden food in rooks (Corvus frugilegus)? Behavioural Processes, 88(2), 88–93.
Abstract: Other individual's head- and eye-directions can be used as social cues indicating the presence of important events. Among birds, ravens and rooks have been shown to co-orient with conspecifics and with humans by following their gaze direction into distant space and behind visual screens. Both species use screens to cache food in private; also, it had been suggested that they may rely on gaze cues to detect hidden food. However, in an object-choice task, ravens failed to do so, and their competitive lifestyle may have prevented them from relying on these cues. Here we tested closely related and cooperative rooks. Food was hidden in one of two cups and the experimenter gazed at the baited cup. In a second experiment, we aimed to increase the birds’ motivation to choose correctly by increasing the investment needed to obtain the reward. To do so, the birds had to pull on a string to obtain the cup. Here, the birds as a group tended to rely on gaze cues. In addition, individual birds quickly learned to use the cue in both experiments. Although rooks may not use gaze cues to find hidden food spontaneously, they may quickly learn to do so.
|
Hirata, S. (2007). A note on the responses of chimpanzees (Pan troglodytes) to live self-images on television monitors. Behav. Process., 75(1), 85–90.
Abstract: The majority of studies on self-recognition in animals have been conducted using a mirror as the test device; little is known, however, about the responses of non-human primates toward their own images in media other than mirrors. This study provides preliminary data on the reactions of 10 chimpanzees to live self-images projected on two television monitors, each connected to a different video camera. Chimpanzees could see live images of their own faces, which were approximately life-sized, on one monitor. On the other monitor, they could see live images of their whole body, which were approximately one-fifth life-size, viewed diagonally from behind. In addition, several objects were introduced into the test situation. Out of 10 chimpanzees tested, 2 individuals performed self-exploratory behaviors while watching their own images on the monitors. One of these two chimpanzees successively picked up two of the provided objects in front of a monitor, and watched the images of these objects on the monitor. The results indicate that these chimpanzees were able to immediately recognize live images of themselves or objects on the monitors, even though several features of these images differed from those of their previous experience with mirrors.
|
Sueur, C., & Petit, O. (2008). Shared or unshared consensus decision in macaques? Behav. Process., 78(1), 84–92.
Abstract: Members of a social group have to make collective decisions in order to synchronise their activities. In a shared consensus decision, all group members can take part in the decision whereas in an unshared consensus decision, one individual, usually a dominant member of the group, takes the decision for the rest of the group. It has been suggested that the type of decision-making of a species could be influenced by its social style. To investigate this further, we studied collective movements in two species with opposed social systems, the Tonkean macaque (Macaca tonkeana) and the rhesus macaque (Macaca mulatta). From our results, it appears that the decision to move is the result of the choices and actions of several individuals in both groups. However, this consensus decision involved nearly all group members in Tonkean macaques whereas dominant and old individuals took a prominent role in rhesus macaques. Thus, we suggest that Tonkean macaques display equally shared consensus decisions to move, whereas in the same context rhesus macaque exhibit partially shared consensus decisions. Such a difference in making a collective decision might be linked to the different social systems of the two studied species.
|
Cloutier, S., Newberry, R. C., & Honda, K. (2004). Comparison of social ranks based on worm-running and aggressive behaviour in young domestic fowl. Behav. Process., 65(1), 79–86.
Abstract: Worm-running is behaviour in which a chick runs carrying a worm-like object while flock mates follow and attempt to grab the object from its beak. We hypothesised that social ranks based on worm-running frequency are stable over time and are positively correlated with social ranks based on success in aggressive interactions when older. At 8-12 days of age, we scored worm-running in 17 groups of 12 female White Leghorn chicks during three 10-min tests. Based on instantaneous scans at 5-s intervals, the bird carrying the `worm' most often was placed in rank one and so on down the rank order. These tests were repeated at 68-70 days of age. An aggression index for each bird was calculated as the number of aggressive acts given, divided by the number given and received, during three 1-h observation periods when the birds were 68-70 days. Ranks obtained in worm-running tests were positively correlated over the two age periods (P<0.05) but were not correlated with ranks based on the aggression index (P>0.05). Our results indicate that worm-running ranks are not predictive of success in aggressive interactions. Instead, worm-running fits some criteria for play.
|
|
Mercado E., Killebrew D.A., Pack A.A., Macha I.V.B., & Herman L.M. (2000). Generalization of 'same-different' classification abilities in bottlenosed dolphins. Behav. Process., 50, 79–94.
|
Daniels, T. J., & Bekoff, M. (1989). Feralization: The making of wild domestic animals. Behav. Process., 19(1-3), 79–94.
Abstract: The widely accepted viewpoint that feralization is the reverse of domestication requires that the feralization process be restricted to populations of animals and, therefore, cannot occur in individuals. An alternative, ontogenetic approach is presented in which feralization is defined as the process by which individual domestic animals either become desocialized from humans, or never become socialized, and thus behave as untamed, non-domestic animals. Feralization will vary among species and, intraspecifically, will depend upon an individual's age and history of socialization to humans. Because feralization is not equated with morphological change resulting from evolutionary processes, species formation is not an accurate indicator of feral condition.
|
Poling, A., Thomas, J., Hall-Johnson, E., & Picker, M. (1985). Self-control revisited: Some factors that affect autoshaped responding. Behav. Process., 10(1-2), 77–85.
Abstract: Pigeons were exposed to autoshaping procedures under which 50% of red key illuminations were followed by 9-sec food deliveries, and 50% of blue key illuminations were followed by 3-sec food deliveries. When all key illuminations were 6 sec, pigeons preferred the red stimulus. Subsequent manipulations demonstrated that preference could be shifted to the blue stimulus by either increasing the duration of the red stimulus or imposing a delay interval between the offset of that stimulus and food delivery. A final experiment demonstrated that, in two of three subjects, preference for key illuminations associated with longer, but delayed, food deliveries generally increased as the duration of all key illuminations was lengthened. These results, obtained under conditions where keypecking had no programmed consequences, are similar to those previously observed under procedures involving a positive response-food dependency.
|
