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Hauser, M. D., Kralik, J., Botto-Mahan, C., Garrett, M., & Oser, J. (1995). Self-recognition in primates: phylogeny and the salience of species-typical features. Proc. Natl. Acad. Sci. U.S.A., 92(23), 10811–10814.
Abstract: Self-recognition has been explored in nonlinguistic organisms by recording whether individuals touch a dye-marked area on visually inaccessible parts of their face while looking in a mirror or inspect parts of their body while using the mirror's reflection. Only chimpanzees, gorillas, orangutans, and humans over the age of approximately 2 years consistently evidence self-directed mirror-guided behavior without experimenter training. To evaluate the inferred phylogenetic gap between hominoids and other animals, a modified dye-mark test was conducted with cotton-top tamarins (Saguinus oedipus), a New World monkey species. The white hair on the tamarins' head was color-dyed, thereby significantly altering a visually distinctive species-typical feature. Only individuals with dyed hair and prior mirror exposure touched their head while looking in the mirror. They looked longer in the mirror than controls, and some individuals used the mirror to observe visually inaccessible body parts. Prior failures to pass the mirror test may have been due to methodological problems, rather than to phylogenetic differences in the capacity for self-recognition. Specifically, an individual's sensitivity to experimentally modified parts of its body may depend crucially on the relative saliency of the modified part (e.g., face versus hair). Moreover, and in contrast to previous claims, we suggest that the mirror test may not be sufficient for assessing the concept of self or mental state attribution in nonlinguistic organisms.
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Heyes CM. (1995). Self-recognition in primates: further reflections create a hall of mirrors. Anim. Behav., 50, 1533.
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Anderson, J. R. (1995). Self-recognition in dolphins: credible cetaceans; compromised criteria, controls, and conclusions. Conscious Cogn, 4(2), 239–243.
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Skandakumar, S., Stodulski, G., & Hau, J. (1995). Salivary IgA: a Possible Stress Marker In Dogs. In Animal Welfare (Vol. 4, pp. 339–350).
Abstract: Stress in humans has been reported to be associated with a decrease in the salivary immunoglobulin A (s-IgA) levels enabling the possible use of s-IgA to assess stress. Prolonged stress, if reliably assessed in a non-invasive manner, may be used to assess animal welfare. This study analysed groups of dogs undergoing physical and temperamental training and s-IgA levels were measured by rocket immunoelectrophoresis in prospective samples. Behavioural assessment was carried out and cortisol levels in saliva were measured by ELISA. A significant negative correlation (P < 0.007) between the logarithmic cortisol concentrations and s-IgA levels in saliva was recorded. The behavioural assessment of the dogs agreed well with the biochemical markers. It is concluded that IgA levels in saliva may be a useful marker of dog well-being and that stress results in decreased s-IgA levels.
Keywords: Animal Welfare; Behaviour; Cortisol; Dog; Salivary Iga (S-Iga); Stress; Well-Being
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Boysen, S. T., & Berntson, G. G. (1995). Responses to quantity: perceptual versus cognitive mechanisms in chimpanzees (Pan troglodytes). J Exp Psychol Anim Behav Process, 21(1), 82–86.
Abstract: Two chimpanzees were trained to select among 2 different amounts of candy (1-6 items). The task was designed so that selection of either array by the active (selector) chimpanzee resulted in that array being given to the passive (observer) animal, with the remaining (nonselected) array going to the selector. Neither animal was able to select consistently the smaller array, which would reap the larger reward. Rather, both animals preferentially selected the larger array, thereby receiving the smaller number of reinforcers. When Arabic numerals were substituted for the food arrays, however, the selector animal evidenced more optimal performance, immediately selecting the smaller numeral and thus receiving the larger reward. These findings suggest that a basic predisposition to respond to the perceptual-motivational features of incentive stimuli can interfere with task performance and that this interference can be overridden when abstract symbols serve as choice stimuli.
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McGreevy, P. D., Richardson, J. D., Nicol, C. J., & Lane, J. G. (1995). Radiographic and endoscopic study of horses performing an oral based stereotypy. Equine Vet J, 27(2), 92–95.
Abstract: There is confusion in the veterinary literature concerning the definition of oral based stereotypies in the horse. This study reports the use of fluoroscopy and endoscopy during cribbiting/wind-sucking in afflicted horses. This permitted observations of movements of the pharyngeal and oesophageal tissues and of the air column within during the stereotypic behaviour. The findings reported show that the sequence of events during crib-biting/wind-sucking is not related to deglutition and that air is not swallowed to the stomach. Transient dilation of the upper oesophagus was recorded and the characteristic noise of wind-sucking coincided with the in-rush of air through the cricopharynx. The oesophageal distension was relieved when the air returned to the pharynx although small quantities passed caudally. It is proposed that the role of contraction of the strap muscles of the neck is to create a pressure gradient in the soft tissues surrounding the oesophagus which provokes movement of air from the pharynx into the oesophagus. The findings suggest that the definitions currently used in the sale of horses are in need of revision.
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Clutton-Brock, T. H., & Parker, G. A. (1995). Punishment in animal societies. Nature, 373(6511), 209–216.
Abstract: Although positive reciprocity (reciprocal altruism) has been a focus of interest in evolutionary biology, negative reciprocity (retaliatory infliction of fitness reduction) has been largely ignored. In social animals, retaliatory aggression is common, individuals often punish other group members that infringe their interests, and punishment can cause subordinates to desist from behaviour likely to reduce the fitness of dominant animals. Punishing strategies are used to establish and maintain dominance relationships, to discourage parasites and cheats, to discipline offspring or prospective sexual partners and to maintain cooperative behaviour.
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Templeton, J. J., & Giraldeau, L. - A. (1995). Public information cues affect the scrounging decisions of starlings.49(6), 1617–1626.
Abstract: The foraging decisions that individuals make within groups should depend on the information available to them. An aviary experiment was conducted to examine whether a starling's, Sturnus vulgaris, decisions either to approach and feed from (scrounge) or to avoid the patches exploited by a partner bird are influenced by the information the partner provides. Both the type of information a subject could recognize and the point at which this information became available during the partner's exploitation of a patch were manipulaed. Information concerning the quality of a patch was available in the form of a concealed colour cue and from the behaviour of the partner bird. The foraging environment was manipulated such that colour cues were either present or absent, and provided either correct or incorrect information concerning the presence of food. When cues corresponded with past foraging experience, test subjects responded selectively and profitably to the patch exploitations of the partner; they scrounged from a higher proportion of profitable patches than control birds, which lacked the ability to recognize colour cues. Test subjects also arrived more quickly at profitable patches that the partner bird discovered than did control birds; and consequently, were able to obtain more food at each food patch scrounged. Finally, test subjects avoided scrounging when the partner discovered empty patches and thus saved foraging time. Responding selectively to public information, therefore, allows an individual to compete more effectively for resources within a foraging group.
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Saltz, D., & Rubenstein D.I. (1995). Population Dynamics of a Reintroduced Asiatic Wild Ass (Equus Hemionus) Herd. Ecol Appl, 5(2), 327–335.
Abstract: Reintroduction is the release of animals into an area where they were extirpated or have significantly declined. Little is known about the factors that determine the success of failure of ungulate reintroduction. We studied the dynamics of a reintroduced Asiatic wild ass (Equus hemionus) population for 10 yr (1983-1993) following the first successful release into the wild. A total of 14 adult females and 14 adult males were released into a nature reserve in the Negev Desert of southern Israel. Over this 10-yr span the female population has grown to only 16 adults. Reproductive success of reintroduced females was low in the first 5 yr following release (0.0-0.8 foals@?female^-^1@?yr^-^1), but increased to 0.5-1.0 foals@?female^-^1@?yr^-^1 in the last 5 yr. Reproductive success of wild-born females @>3 yr old was higher than that of reintroduced females of similar ages, and ranged from 0.5-1.0 foals@?female@?^-^1yr^-^1. Our study and data from the E. hemionus studbook suggest that young nonprimiparous females produced primarily males, while primiparous and old females produced primarily females. We attribute the low reproductive success following reintroduction to the stress caused by capture, transport, and release procedures; we consider the age-dependent progeny sex ratio within the framework of Trivers and Willard's (1973) maternal allocation hypothesis. We conclude that the slow growth of the female population was due to: (a) low reproductive success of females in the early years following reintroduction, and (b) a male-skewed progeny sex ratio among prime-aged reintroduced females. A simple stochastic Leslie matrix model suggests that high survival and improved reproductive success of reintroduced females at later stages of the study, and the reproductive success of wild-born females, make the population relatively unsusceptible to extinction from random demographic processes. In-depth knowledge of the dynamics of reintroduced populations is vital for the correct assessment of their viability. We offer suggestions for increasing the efficacy of future wild ass reintroductions.
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Madigan, J. E., Kortz, G., Murphy, C., & Rodger, L. (1995). Photic headshaking in the horse: 7 cases. Equine Vet J, 27(4), 306–311.
Abstract: Seven horses with headshaking are described. No physical abnormalities were detected in any of the cases. Six of these horses had onset of clinical signs in the spring. The role of light was assessed by application of a blindfold or dark grey lens to the eyes, covering the eyes with a face mask and observing the horse in total darkness outdoors. Cessation of headshaking was observed with blindfolding (5/5 horses), night darkness outdoors (4/4 horses) and use of grey lenses (2/3 horses). Outdoor behaviour suggested efforts to avoid light in 4/4 cases. The photic sneeze in man is suggested as a putative mechanism for equine headshaking. Five of 7 horses had improvement with cyproheptadine treatment (0.3 mg/kg bwt b.i.d.). Headshaking developed within 2 calendar weeks of the same date for 3 consecutive years in one horse. Neuropharmacological alterations associated with photoperiod mechanisms leading to optic trigeminal summation are suggested as possible reasons for spring onset of headshaking.
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