Abstract: Forty-four horses were used to determine if a learned stimulus could be used to increase acquisition of a response unrelated to the original learned task. Horses were paired by age, breed and sex. One randomly chosen horse from each pair served as the control while the remaining horse was trained to respond to a visual stimulus by pushing a lever to obtain a food reward. In Experiment I (n=28), the food reward was delivered in a feed box located equidistant between two levers located 2.7 m apart on one wall of the test stall. Trained horses were given 30 training trials daily until they achieved at least 85% correct responses in three nonconsecutive days. After each trained horse reached criterion, both horses in the pair were tested in 30 trials daily for five consecutive days in a modified Y maze. The stimulus that indicated the correct lever in the initial training task was used to signify the correct arm of the maze for both the control and trained horses. The correct arm of the maze was changed randomly during each daily session, and correct choices resulted in a food reward. In Experiment II (n=16), levers were located on opposite walls (11 m apart) of the test stall, and the stimulus and modified Y maze were simplified. Trained horses received 15 training trials daily until they reached at least 85% correct responses on three consecutive days. As each trained horse achieved this criterion, both horses in the pair were tested in a maze for 15 trials daily for 7 days. Again, the stimulus from initial lever-pressing task was used to signify the rewarded arm of the maze. Correct choices of trained and control horses in both experiments were compared using a paired t-test. In Experiment I, no differences (P>0.34) in mean correct responses were detected between trained and control horses on the first day in the maze (15.3 and 16.8, respectively) or after 5 days in the maze (84.0 and 82.1, respectively). Similarly, in Experiment II, trained and control horses did not differ (P>0.50) in mean correct responses on the first day (6.9 and 7.4, respectively) or after 7 days in the maze (63.6 and 61.6, respectively). These results indicate that the stimuli used to solve the lever-pressing task were not utilized by horses in the maze task, and that horses may have difficulty transferring learned visual stimuli to new tasks.

Abstract: Tail-biting and other harmful social behaviours are a common problem on pig farms. The aims of the current experiment were (1) to investigate the genetic component of harmful social behaviours such as tail-biting by assessing breed differences, and (2) to further investigate the reliability and predictability of a test, [`]the tail-chew test', previously identified as potentially being capable of predicting a pig's predisposition for tail- and ear-biting. The behaviour of three pig breeds (Large White (LW), Landrace (LR), Duroc (DR)), with 100 pigs per breed, was observed in a [`]tail-chew test', and by observing the performance of harmful social behaviour directed to pen mates in flat deck pens after weaning. The tail-chew test, carried out on two consecutive days pre-weaning, involved observing the behaviour of individual pigs towards two suspended ropes. Pigs were weaned at 28 days and the occurrence of harmful social behaviour was recorded 4 weeks later over 2 consecutive days (1 h per day) using a group [`]period occurrence' scanning method. Breed had a significant effect on rope-directed behaviour in the tail-chew test and on harmful social behaviour. DR pigs interacted with the ropes in the tail-chew test more often (median 23.0 vs 19.0 and 17.5 times in 20 min, P<0.001) and for longer (31.0 vs 20.0 and 23.2 s, P<0.001) than LR and LW pigs, respectively. Although not significantly different from LW, DR pigs tended to direct more total harmful social behaviour towards pen mates than the other breeds. In particular, DR were observed in more total pig-directed biting of pen mates (median 9.0 vs 6.0 and 7.0, P<0.01) than LR and LW, and tended to nose pen mates more often than the other breeds (13.0 vs 11.0 and 10.0, P=0.06). LR pigs bit the ears of pen mates less often than LW and DR (4.0 vs 5.0 and 6.0, P<0.001). Belly-nosing activity was low, with a median of 0 for all breeds, but LR belly-nosed pen mates more often than Durocs (interquartile ranges 0-2.0 vs 0-1.0 and 0-1.0, P<0.01). The behaviour observed in the tail-chew test on day 1 correlated significantly with that observed on day 2 of the test (e.g. frequency of rope-directed behaviour rs=0.380,P<0.01). There were significant but weak correlations between rope-directed behaviour and the performance of some harmful social behaviours. The significant breed differences indicate some genetic contribution to expression of harmful social behaviours. However, the tail-chew test was found to be of limited ability to predict tail- and ear-biting under commercial conditions.

Abstract: In animal communication natural selection favors callers who vocalize to affect the behavior of listeners and listeners who acquire information from vocalizations, using this information to represent their environment. The acquisition of information in the wild is similar to the learning that occurs in laboratory conditioning experiments. It also has some parallels with language. The dichotomous view that animal signals must be either referential or emotional is false, because they can easily be both: The mechanisms that cause a signaler to vocalize do not limit a listener's ability to extract information from the call. The inability of most animals to recognize the mental states of others distinguishes animal communication most clearly from human language. Whereas signalers may vocalize to change a listener's behavior, they do not call to inform others. Listeners acquire information from signalers who do not, in the human sense, intend to provide it.

Abstract: Historically, a dichotomy has been drawn between the semantic communication of human language and the apparently emotional calls of animals. Current research paints a more complicated picture. Just as scientists have identified elements of human speech that reflect a speaker's emotions, field experiments have shown that the calls of many animals provide listeners with information about objects and events in the environment. Like human speech, therefore, animal vocalizations simultaneously provide others with information that is both semantic and emotional. In support of this conclusion, we review the results of field experiments on the natural vocalizations of African vervet monkeys, diana monkeys, baboons, and suricates (a South African mongoose). Vervet and diana monkeys give acoustically distinct alarm calls in response to the presence of leopards, eagles, and snakes. Each alarm call type elicits a different, adaptive response from others nearby. Field experiments demonstrate that listeners compare these vocalizations not just according to their acoustic properties but also according to the information they convey. Like monkeys, suricates give acoustically distinct alarm calls in response to different predators. Within each predator class, the calls also differ acoustically according to the signaler's perception of urgency. Like speech, therefore, suricate alarm calls convey both semantic and emotional information. The vocalizations of baboons, like those of many birds and mammals, are individually distinctive. As a result, when one baboon hears a sequence of calls exchanged between two or more individuals, the listener acquires information about social events in its group. Baboons, moreover, are skilled “eavesdroppers:” their response to different call sequences provides evidence of the sophisticated information they acquire from other individuals' vocalizations. Baboon males give loud “wahoo” calls during competitive displays. Like other vocalizations, these highly emotional calls provide listeners with information about the caller's dominance rank, age, and competitive ability. Although animal vocalizations, like human speech, simultaneously encode both semantic and emotional information, they differ from language in at least one fundamental respect. Although listeners acquire rich information from a caller's vocalization, callers do not, in the human sense, intend to provide it. Listeners acquire information as an inadvertent consequence of signaler behavior.