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Miklósi, A. '., Polgárdi, R., Topál, J., & Csányi, V. (2000). Intentional behaviour in dog-human communication: an experimental analysis of “showing” behaviour in the dog. Anim. Cogn., 3(3), 159–166.
Abstract: Despite earlier scepticism there is now evidence for simple forms of intentional and functionally referential communication in many animal species. Here we investigate whether dogs engage in functional referential communication with their owners. “Showing” is defined as a communicative action consisting of both a directional component related to an external target and an attention-getting component that directs the attention of the perceiver to the informer or sender. In our experimental situation dogs witness the hiding of a piece of food (or a favourite toy) which they cannot get access to. We asked whether dogs would engage in “showing” in the presence of their owner. To control for the motivational effects of both the owner and the food on the dogs' behaviour, control observations were also staged where only the food (or the toy) or the owner was present. Dogs' gazing frequency at both the food (toy) and the owner was greater when only one of these was present. In other words, dogs looked more frequently at their owner when the food (toy) was present, and they looked more at the location of the food (toy) when the owner was present. When both the food (toy) and the owner were present a new behaviour, “gaze alternation”, emerged which was defined as changing the direction of the gaze from the location of the food (toy) to looking at the owner (or vice versa) within 2 s. Vocalisations that occurred in this phase were always associated with gazing at the owner or the location of the food. This behaviour, which was specific to this situation, has also been described in chimpanzees, a gorilla and humans, and has often been interpreted as a form of functionally referential communication. Based on our observations we argue that dogs might be able to engage in functionally referential communication with their owner, and their behaviour could be described as a form of “showing”. The contribution of domestication and individual learning to the well-developed communicative skills in dogs is discussed and will be the subject of further studies.
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Yang, S. (2000). Melioidosis research in China. Acta Trop, 77(2), 157–165.
Abstract: Research on melioidosis and its pathogen has been ongoing in China for more than two decades. It has been demonstrated that the natural foci are located predominantly in Hainan, Guangdong and Guangxi province, where there is a good correlation between soil isolation and the serum prevalence of antibodies to Burkholderia pseudomallei. The cases of melioidosis reported up to now are concentrated in the Hainan and Zhanjiang peninsula. Investigations on serotype, virulence, ecology, antibiotic susceptibility, whole cell analysis by gas chromatography, and genetics have led to a new understanding of the pathology of the disease. Immunological cross reactions between Burkholderia mallei and B. pseudomallei and the difference between melioidosis and glanders in horses is discussed.
Keywords: Animals; Anti-Bacterial Agents/pharmacology; Burkholderia pseudomallei/drug effects/immunology/*pathogenicity; China/epidemiology; Cross Reactions; Glanders/immunology/microbiology; Horses; Humans; *Melioidosis/epidemiology/immunology/microbiology/veterinary; Seroepidemiologic Studies; Virulence
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Ray, E. D., Gardner, M. R., & Heyes, C. M. (2000). Seeing how it's done: matching conditions for observer rats (Rattus norvegicus) in the bidirectional control. Anim. Cogn., 3(3), 147–157.
Abstract: In an attempt to increase the reliability of the demonstrator-consistent responding effect produced in the bidirectional control procedure, experiments 1-4 sought conditions that would magnify the matching effect. The aim was to produce a robust demonstrator-consistent responding effect in order that future analytic experiments could investigate the psychological processes responsible for this effect. The joystick responses of observer rats trained using the standard bidirectional control procedure parameters were compared with those of observers subject to conditions identified in the social learning literature as favourable for imitation. Unlike mice, observer rats in experiments 1 a and 1 b tended to push a joystick in the same direction as their demonstrators when the demonstrators were either familiar or unfamiliar males and females. Comparable demonstrator-consistent responding occurred following observation of a standard and a salient joystick response (experiment 2). Experiment 3 showed that the discriminative accuracy of a demonstrator's responding was important for matching behaviour, and suggested that matching might be enhanced with more than the conventional single observation session. Experiment 4 confirmed that the bidirectional control effect is sensitive to the amount of observational experience; after six observation sessions, demonstrator-inconsistent responding occurs. The results of experiments 1-3 are, and those of experiment 4 are not, compatible with the hypothesis that demonstrator-consistent responding in the bidirectional control is caused by olfactory cues deposited by demonstrators on the joystick.
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Linklater, W. L., Cameron, E. Z., Stafford, K. J., & Veltman, C. J. (2000). Social and spatial structure and range use by Kaimanawa wild horses (Equus caballus: Equidae). New Zealand J. Ecol., 24(2), 139–152.
Abstract: We measured horse density, social structure, habitat use, home ranges and altitudinal micro-climates in the south-western Kaimanawa ranges east of Waiouru, New Zealand. Horse density in the Auahitotara ecological sector averaged 3.6 horses.km-2 and ranged from 0.9 to 5.2 horses.km-2 within different zones. The population's social structure was like that of other feral horse populations with an even adult sex ratio, year round breeding groups (bands) with stable adult membership consisting of 1 to 11 mares, 1 to 4 stallions, and their predispersal offspring, and bachelor groups with unstable membership. Bands and bachelor males were loyal to undefended home ranges with central core use areas. Band home range sizes varied positively with adult band size. Home ranges overlapped entirely with other home ranges. Horses were more likely to occupy north facing aspects, short tussock vegetation and flush zones and avoid high altitudes, southern aspects, steeper slopes, bare ground and forest remnants. Horses were more likely to be on north facing aspects, steeper slopes, in exotic and red tussock grasslands and flush zones during winter and at lower altitudes and on gentler slopes in spring and summer. Seasonal shifts by bands to river basin and stream valley floors in spring and higher altitudes in autumn and winter are attributed to the beginning of foaling and mating in spring and formation of frost inversion layers in winter. Given horse habitat selectivity and the presence of other ungulate herbivores, results from present exclosures are likely to exaggerate the size of horse impacts on range vegetation. Proposals to manage the population by relocation and confinement are likely to modify current social structure and range use behaviour and may lead to the need for more intensive management in the longer term.
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Durier, V., & Rivault, C. (2000). Learning and foraging efficiency in German cockroaches, Blattella germanica (L.) (Insecta: Dictyoptera). Anim. Cogn., 3(3), 139–145.
Abstract: We analysed, under laboratory test conditions, how German cockroach larvae oriented their outgoing foraging trip from their shelter. Our results stressed the importance of external factors, like availability and spatial distribution of food sources, in the choice of a foraging strategy within their home range. When food sources were randomly distributed, larvae adopted a random food search strategy. When food distribution was spatially predictable and reliable, cockroaches were able to relate the presence of food with a landmark during a 3-day training period and to develop an oriented search strategy. Cockroaches were able to associate learned spatial information about their home range to the presence of food resources and then to improve their foraging efficiency. However, conflict experiments revealed that detection of food odour overrode learned landmark cues.
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Forkman, B. (2000). Domestic hens have declarative representations. Anim. Cogn., 3(3), 135–137.
Abstract: It is generally considered that information can be stored either as a procedural or as a declarative representation. A devaluation technique was used to determine whether hens have declarative representations. Individual hens (Gallus gallus domesticus) were fed in an enclosure with two containers, each with a new food type. One of the food types was devalued by pre-feeding with that food, after which the hens were tested with empty food containers. The pre-feeding should only affect the choice of the hens if they have learned where a particular food type was (declarative representation) rather than “go left when coming into the enclosure” (procedural representation). A significant proportion of the hens went to the location previously occupied by the non-devalued food (seven out of eight). This supports the hypothesis that domestic hens can form declarative representations.
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Waite, T. A., & Field, K. L. (2000). Erroneous choice and foregone gains in hoarding gray jays (Perisoreus canadensis). Anim. Cogn., 3(3), 127–134.
Abstract: Under the conventional assumption that natural selection favors choice behavior that maximizes some fitness-related currency, a forager making repeated binary choices should consistently choose the more valuable option. Under the alternative assumption that natural selection favors choice behavior that minimizes costly errors, erroneous choice is not only expected but is expected to be common when the cost of errors is low. This cost depends on the potential rate of return: the higher this rate, the smaller the cost of choosing the less valuable option. When this rate is very high, a forager may err frequently and yet forego no appreciable fitness gain. Errors should thus be more common when interruptions to foraging are shorter. Our experimental results supported this prediction: gray jays chose the less valuable option more frequently when subjected to shorter interruptions (experimentally imposed delays to access to food rewards). This tendency is consistent with the idea that an adaptive decision-making process may routinely produce errors, not because errors are in some way adaptive but because their fitness cost is minimal, particularly when delays are short. From a proximate perspective, this tendency to commit errors more frequently following shorter delays may be due to constraints on the jays' information-processing capacity. In general, choice behavior should be viewed as the joint byproduct of adaptive decision making and cognitive constraints.
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Baker, P. J., Funk, S. M., Harris, S., & White, P. C. L. (2000). Flexible spatial organization of urban foxes, Vulpes vulpes, before and during an outbreak of sarcoptic mange. Anim. Behav., 59(1), 127–146.
Abstract: The social and spatial organization of urban fox groups prior to and during an outbreak of sarcoptic mange was compared with predictions derived from the resource dispersion hypothesis (RDH). We investigated the availability of three key resources. Neither daytime rest sites nor breeding sites appeared to be limited in availability. The availability of food deliberately supplied by local householders was examined by questionnaire surveys. The daily and weekly amount of food supplied was greatly in excess of the minimum requirements of a pair of foxes, but was consistent between territories. The availability of this food source increased markedly as a result of more people feeding the foxes. In agreement with the RDH, group size prior to the outbreak of mange increased from 2.25 animals (N=4) to 6.57 animals (N=7). Before the outbreak of mange, two territories were divided. Increased scavenge availability on smaller territories may have promoted these changes. Excluding these spatial changes, territories were very stable between years. After the outbreak of mange, group size declined as a direct result of mange-induced mortality. Surviving animals increased their ranges only after neighbouring groups had died out. Ranges did not increase in size in response to a decline in food availability. Nor were the increases in range size associated with the relinquishment of parts of the existing territory. These postmange changes are contrary to the RDH. Three factors may have promoted these changes: the elimination of interstitial space, the forced dispersal of young or future division of the territory.
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Cassinello, J., & Pieters, I. (2000). Multi-male captive groups of endangered dama gazelle: Social rank, aggression, and enclosure effects. Zoo Biol., 19(2), 121–129.
Abstract: A study carried out in four multi-male groups of captive dama gazelle (Gazella dama mhorr) characterized the social rank order of males and possible enclosure effects on aggression rate. A strong relationship between rank and age was found. The results also showed that dominant individuals in the two smallest enclosures were more aggressive than their herdmates, suggesting a more stressful environment, which might precipitate unstable or challenged hierarchies when the animals live in a more restricted enclosure. Subordinate males performed submissive responses at a higher frequency, irrespective of the size of the enclosure. The frequency of interactions between the gazelles, on the other hand, was affected by enclosure size, since high-ranking males showed higher values than low-ranking males in the two smallest enclosures. Frequencies of aggressive acts, retreats, and related interactions were similar in all the herds. Implications for the management of the species in captivity are discussed. Zoo Biol 19:121–129, 2000. © 2000 Wiley-Liss, Inc.
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Goodloe, R. B. (2000). Population characteristics of feral horses on Cumberland Island, Georgia and their management implications. J Wildl Manag, 64(1), 114–121.
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