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Swaddle, J. P., & Witter, M. S. (1995). Chest Plumage, Dominance and Fluctuating Asymmetry in Female Starlings. Proc. Roy. Soc. Lond. B Biol. Sci., 260(1358), 219–223.
Abstract: It has been proposed that levels of fluctuating asymmetry (FA) may be used in establishing and maintaining dominance hierarchies, as asymmetry reflects aspects of individual quality. However, previous manipulations of FA have failed to reveal that the level or outcome of agonistic intra-sexual interactions are affected by levels of FA. In female European starlings (Sturnus vulgaris), correlational data suggest that FA of the speckled chest plumage may be related to dominance status. These data are confounded, however, by total number of spots on the chest and the proportion of the chest that is white, both of which positively covary with chest asymmetry. Thus, we deconfounded the effects of these plumage traits on dominance by experimentally manipulating the number of spots and spot number asymmetry in a factorial design. The results indicated that dominance is influenced by the number of spots on the chest, but not by spot asymmetry. Birds with spottier chests were dominant over birds with experimentally decreased spot number. We suggest that female starlings' chests are exposed to extensive abrasion throughout the breeding season and so are susceptible to damage asymmetries that may mask the `true' fluctuating asymmetry of the trait. This may devalue the use of chest asymmetry as a quality indicator. Spottier chests may be costly to maintain, in part because of increased susceptibility to abrasion, and so may be a better indicator of quality than asymmetry.
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Ben-Shahar, R. (1995). Habitat classification in relation to movements and densities of ungulates in a semi-arid savanna. Afr. J. Ecol., 33, 50–63.
Abstract: Habitat types were classified in a semi-arid nature reserve in South Africa in order to assess the spatial requirements of resident ungulates, namely zebra, wildebeest and impala. Multivariate analyses showed patterns of soil factors and plant species associations that corresponded with variations of local geological formations and the abundance of plants. The response of ungulates to habitats of different degrees of complexity in terms of soils and plant species associations was examined on the basis of annual occurrence. New habitat types were described through merging or subdividing the existing classification. New habitat categories which corresponded with high occurrences of ungulates provided better indications of the resource requirements for large herbivores. Wildebeest were restricted in their habitat requirements and were characterized by high seasonal densities in bottom lands, particularly during the late wet period. There was a considerable overlap in the preference of habitat types between wildebeest and zebra although zebra were aggregated during longer periods within the dolerite formation. Impala had a consistent annual preference for the granite formation where seepage lines and bottom lands were inhabited seasonally by large herd concentrations.
Résumé
On a classifié les types d'habitat dans une réserve naturelle semiaride d'Afrique du Sud, dans le but d'évaluer les exigences spatiales des ongulés qui y vivent, c'est à dire les zèbres, les gnous et les impalas. Des analyses multivariées ont révélé des schémas pour les facteurs du sol et pour les associations d'espèces végétales qui correspondent aux variations des formations géologiques locales et à l'abon-dance des plantes. On a examiné la réponse des ongulés à des habitats de complexité différente en termes de sols et d'associations d'espéces végétales, d'après leur présence annuelle. On a décrit de nouveaux types d'habitats en fusionnant ou en subdivisant la classification existante. Les nouvelles catégories d'habitats qui correspondaient à des présences abondantes d'ongulés ont fourni de meilleures indications sur les ressources exigées par les grands herbivores. Les gnous se limitaient aux endroits qui répondaient a leurs exigences et se caractérisaient par de hautes densités saisonnières dans les régions basses, spécialement pendant la dernière saison des pluies. Il y avait un recouvrement considérable des types d'habitats préferés par les gnous et les zébres, encore que les zébres se rassemblent plus longtemps dans la formation doléritique. Les impalas marquent une préférence annuelle constante pour la formation granitique où les sources et les terres basses sont occupées de façon saisonnière par des hardes très concentrées.
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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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Maddock, L. (1995). The “migration” and grazing succession. In A. R. E. Sinclair, & A. R. E. Norton-Griffiths (Eds.), Serengeti: Dynamics of an Ecosystem. Chicago: University Of Chicago Press.
Abstract: Editorial Reviews
Book Description
Originally published in 1979, Serengeti: Dynamics of an Ecosystem was immediately recognized as the first synthesis of the patterns and processes of a major ecosystem. A prototype for initial studies, Serengeti contains baseline data for further and comparative studies of ecosystems. The new Serengeti II builds on the information presented originally in Serengeti; both books together offer essential information and insights for ecology and conservation biology.
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VanDierendonck, M. C., de Vries, H., Schilder, M.B.H. (1995). An Analysis of Dominance, Its Behavioural Parameters and Possible Determinants in a Herd of Icelandic horses in captivity. Netherl. J. Zool., 45(3-4), 362–385.
Abstract: Feral horses are social animals, which have to rely on survival strategies centered on the formation of cohesive social bonds within their bands. Many problems in the husbandry of social animals such as horses, are due to the fact that the limits of their adaptive abilities are exceeded. Evidence suggests that the fundamental social characteristics of domestic horses have remained relatively unchanged. The social structure, social strategies and social interactions were investigated (3 non-consecutive years, 24 hr per day for several weeks) in long term established groups of domestic horses (mares and geldings of all ages) and a few small introduced groups, kept in (semi)natural environments. The general aim was to investigate the social needs of domestic horses. The social life of domestic horses was characterised by long lasting bonds with preferred partners which were established and maintained by allogrooming, play, proximity and dominance behaviours. Bonding partners were mainly found within the same sex-age group, but adult geldings also bonded with sub-adult mares and geldings. Adult mares were clustered in a group, while the other animals formed a second group. Among the adult mares, subgroups according to reproductive state were formed. Individuals regulated their social network by interfering with interactions between other members of the herd, which in itself is complex. An intervention is a behavioural action of one animal that actively interferes with an ongoing interaction between a dyad with the apparent aim of altering that interaction. This was verified by post-hoc analyses of disturbed and undisturbed interactions. Interventions in allogrooming or play were performed significantly more often when at least one member of the initial dyad was a preferred partner of, or familiar to (within the small introduced bands) the intervener. The stronger the preferred association in allogrooming between the intervener and member(s) of the initial dyad, the higher the probability the intervener would displace one initial member and continue allogrooming with the other. Just five behaviours were extracted which reliably reflected the dominance relations among horses. Aggression with the hind quarters was used both offensively and defensively and therefore not suitable as a reliable parameter. Individual dominance relationships were related to social experience. The implications of these findings for horse husbandry were assessed. It is argued that the execution of affiliative behaviours may be rewarding in itself, and therefore always will be a highly motivated behaviour. It is shown that social positive physical interactions (allogrooming, play) with other horses is an ethological need and therefore indispensable in modern husbandry systems. Ethological needs are so important for the animal that husbandry systems that lack the possibilities to execute such behaviours will cause chronic stress. It is concluded that all horses need physical social contact, and that horses, which lack appropriate social learning experiences during ontogeny, may be hampered in their social functioning later in life. Solutions for problems, including dominance problems, in individual social housing and group housing are presented.
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No authors listed. (1995). Workshop on the geographic spread of Aedes albopictus in Europe and the concern among public health authorities. Proceedings of a workshop held at the Istituto Superiore di Sanita, Rome, Italy, 19-20 December 1994. In Parassitologia (Vol. 37, pp. 87–90).
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Kiltie, R. A., Fan, J., & Laine, A. F. (1995). A wavelet-based metric for visual texture discrimination with applications in evolutionary ecology. Math Biosci, 126(1), 21–39.
Abstract: Much work on natural and sexual selection is concerned with the conspicuousness of visual patterns (textures) on animal and plant surfaces. Previous attempts by evolutionary biologists to quantify apparency of such textures have involved subjective estimates of conspicuousness or statistical analyses based on transect samples. We present a method based on wavelet analysis that avoids subjectivity and that uses more of the information in image textures than transects do. Like the human visual system for texture discrimination, and probably like that of other vertebrates, this method is based on localized analysis of orientation and frequency components of the patterns composing visual textures. As examples of the metric's utility, we present analyses of crypsis for tigers, zebras, and peppered moth morphs.
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Pere, M. C. (1995). Maternal and fetal blood levels of glucose, lactate, fructose, and insulin in the conscious pig. J. Anim Sci., 73(10), 2994–2999.
Abstract: To study nutrition and metabolism in the fetal pig, a chronic catheterization method was developed that allows blood sampling in arteries and veins, at both the umbilical and uterine sources, in the conscious, unstressed animal. A catheter was inserted in the fetal aorta through a femoral artery, and another one was introduced in the umbilical vein. A catheter was put in a femoral artery of the sow so that its end was in the abdominal aorta. A fourth catheter was placed in a uterine vein draining the fetoplacental unit studied. This procedure was applied to 18 Large White primiparous sows at 99 d of gestation. Blood samples were drawn simultaneously using the four catheters before a meal at 103 d of pregnancy, and glucose, insulin, lactate, and fructose were determinated. Glycemia was 2.5 times higher in the sow than in the fetus. The extraction coefficient of glucose by the fetus amounted to 14% of the umbilical supply. The insulin level in the fetal pig was very low ( < 5 microU/mL). Lactate and fructose seemed to originate from the placenta. Blood lactate was 2.6 times lower in the sow than in the fetus, and its extraction coefficient by the fetus amounted to 8%. Fructose in the fetal blood was 2.3 times higher than that of glucose. Fructose was not utilized by the pig fetus. The present results obtained in the fetal pig are comparable to the conclusions drawn from studies with other species.
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Swanson, J. C. (1995). Farm animal well-being and intensive production systems. J. Anim Sci., 73(9), 2744–2751.
Abstract: Animal welfare, or well-being, is a social issue with ethical, scientific, political, and aesthetic properties. Answering questions about the welfare of animals requires scientific definition, assessment, solutions, and public acceptance. With respect to the actual well-being of the animal, most issues are centered on how the animal “feels” when managed within a specific level of confinement, during special agricultural practices (e.g., tail docking, beak trimming, etc.) and handling. Questions of this nature may require exploration of animal cognition, motivation, perception, and emotional states in addition to more commonly recognized indicators of well-being. Several general approaches have emerged for solving problems concerning animal well-being in intensive production systems: environmental, genetic, and therapeutic. Environmental approaches involve modifying existing systems to accommodate specific welfare concerns or development of alternative systems. Genetic approaches involve changing the behavioral and (or) physiological nature of the animal to reduce or eliminate behaviors that are undesirable within intensive system. Therapeutic approaches of a physical (tail docking, beak trimming) and physiological (drug and nutritional therapy) nature bring both concern and promise with regard to the reduction of confinement stress. Finally, the recent focus on commodity quality assurance programs may indirectly provide benefits for animal well-being. Although research in the area of animal well-being will provide important information for better animal management, handling, care, and the physical design of intensive production systems there is still some uncertainty regarding public acceptance. The aesthetics of modern intensive production systems may have as much to do with public acceptance as with science.
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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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