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(1993). Wolves in Europe: status and perspectives. Ettal, Germany: Munich Wildlife Society.
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Murray, M. G., & Brown, D. (1993). Niche Separation of Grazing Ungulates in the Serengeti: An Experimental Test. T. J. Anim. Ecol., 62(2), 380–389.
Abstract: 1. The niche separation of three species of alcelaphine antelope (wildebeest, topi and hartebeest) with similar body size was compared by measuring bite weight, bite rate, intake rate and selectivity of tame animals in plots containing grass at different growth stages. 2. On growing swards, hartebeest had a smaller bite weight and lower intake rate, and were also less selective of green leaf, than either topi or wildebeest. On senescent swards, hartebeest were more selective of leaf than the other two species. 3. Wildebeest had a faster bite rate than either topi or hartebeest on swards with low biomass and high protein content of green leaf (green flush). Bite weight and intake rate of wildebeest and topi were similar despite the difference in breadth of their incisor rows. 4. Topi were significantly more selective of green leaf than the other two species and were the only species to maintain a rapid bite rate on swards with high green leaf biomass. 5. The feeding experiments did not reveal significant cross-overs between species in the rate of food intake on different grass types, but each species was most proficient either in leaf selection or bite rate when feeding on grass swards in a particular growth stage. We suggest that growth stage is a primary determinant of niche separation. 6. In Serengeti, grazing ungulates which migrate are specialists of the earlier growth stages of grass which tend to be transient, while those that are residential specialize on late growth stages which are more enduring. The mobility of species, and the spatial and temporal dynamics of pastures containing different growth stages of grass, contribute to niche separation.
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Negi, G. C. S., Rikhari, H. C., Ram, J., & Singh, S. P. (1993). Foraging Niche Characteristics of Horses, Sheep and Goats in an Alpine Meadow of the Indian Central Himalaya. J. Appl. Ecol, 30(3), 383–394.
Abstract: 1. Data on plant species foraged, foraging hours, bite rate, bite size and species dry matter (DM) removed per species per bite were collected in tussock grass-forb (Grass-F), forb-tussock grass (Forb-G), Trachydium-forb (Forb), Rhododendron-Cassiope and early successional communities from May to September in a moderately foraged Central Himalayan alpine meadow in order to study the foraging niche characteristics of horses, sheep and goats. 2. The three animals together grazed 30 plant species, of which 20 were grazed by horses, 22 by sheep and 16 by goats. 3. The average foraging hours (5.2-13.2), bites per minute (23-51) and mg DM per bite (59-99) for horses, sheep and goats were significantly different in different communities and months. 4. The foraging search cost, reckoned as distance walked per unit DM eaten, was highest for goats (15.4 km kg$^{-1}$), followed by sheep (8.1 km kg$^{-1}$) and horses (1.2 km kg$^{-1}$). 5. Of the total intake of horses (3.25 kg DM day$^{-1}$), the Forb community alone accounted for 40%. Sheep (0.74 kg DM day$^{-1}$) resembled horses in this respect. In contrast, the contribution of this community was negligible in the diet of goats in which the Grass-F community contributed most to the intake. 6. Forbs were the largest dietary category for all animal species. The selection ratio varied from 0.7 to 11.3 for forbs, 1.0 to 7.2 for sedges and 1.1 to 2.5 for grasses. 7. Response breadth (in terms of species grazed) was similar for horses and sheep (0.46 vs. 0.43) and somewhat wider for goats (0.49). 8. Grazing pressures below the carrying capacity of the community appeared to favour botanical diversity.
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Dougherty, D. M., & Lewis, P. (1993). Generalization of a tactile stimulus in horses. J Exp Anal Behav, 59(3), 521–528.
Abstract: Using horses, we investigated the control of operant behavior by a tactile stimulus (the training stimulus) and the generalization of behavior to six other similar test stimuli. In a stall, the experimenters mounted a response panel in the doorway. Located on this panel were a response lever and a grain dispenser. The experimenters secured a tactile-stimulus belt to the horse's back. The stimulus belt was constructed by mounting seven solenoids along a piece of burlap in a manner that allowed each to provide the delivery of a tactile stimulus, a repetitive light tapping, at different locations (spaced 10.0 cm apart) along the horse's back. Two preliminary steps were necessary before generalization testing: training a measurable response (lip pressing) and training on several reinforcement schedules in the presence of a training stimulus (tapping by one of the solenoids). We then gave each horse two generalization test sessions. Results indicated that the horses' behavior was effectively controlled by the training stimulus. Horses made the greatest number of responses to the training stimulus, and the tendency to respond to the other test stimuli diminished as the stimuli became farther away from the training stimulus. These findings are discussed in the context of behavioral principles and their relevance to the training of horses.
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Byrne, R. W. (1993). Do larger brains mean greater intelligence? Behav. Brain Sci., 16(4), 696–697.
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Mal, M. E., McCall, C. A., Newland, C., & Cummins, K. A. (1993). Evaluation of a one-trial learning apparatus to test learning ability in weanling horses. Appl. Anim. Behav. Sci., 35(4), 305–311.
Abstract: Fourteen Arabian foals were used to determine if a one-trial appetitive conditioning task, developed for laboratory rats, could be adapted for use in equine learning research. The learning apparatus consisted of a 1.5 m x 0.6 m wooden grid containing 40 compartments. Seven foals received a complete learning test which consisted of placing a foal in a pen with the learning apparatus on one wall, recording the foal's behavior for 5 min and then placing a food reinforcer in a target compartment (TC). After location of the food, the foal's behavior was recorded for an additional 5 min. Total visits made to the apparatus and compartments visited by the foal were recorded. The remaining seven foals received a test in which no reinforcer was placed in the TC. These foals were re-tested the next day with reinforcement. After location of the food reinforcer, all foals exhibited more visits to the apparatus, visits to the TC, visits one compartment from the TC, and visits greater than one and less than or equal to two compartments from the TC (P<0.05). Mean distance of visits from the TC decreased after location of the reinforcer (P<0.05). Increased frequency of visits to the apparatus and concentration of visits around the TC after finding the reinforcer suggest that foals had learned the location of the reinforcer. Results suggest that a one-trial appetitive conditioning test may be applicable in equine learning research.
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Poletaeva, I. I., Popova, N. V., & Romanova, L. G. (1993). Genetic aspects of animal reasoning. Behavior Genetics, 23(5), 467–475.
Abstract: This paper reviews the investigations of Prof. L. V. Krushinsky and his colleagues into the genetics of complex behaviors in mammals. The ability of animals to extrapolate the direction of a food stimulus movement was investigated in wild and domesticated foxes (including different fur-color mutants), wild brown rats, and laboratory rats and mice. Wild animals (raised in the laboratory) were shown to be superior to their respective domesticated forms on performance of the extrapolation task, especially in their scores for the first presentation, in which no previous experience could be used. Laboratory rats and mice demonstrated a low level of extrapolation performance. This means that only a few laboratory animals were capable of solving the task, i.e., the percentage of correct solutions was equivalent to chance. The brain weight selection program resulted in two mice strains with a 20% (90-mg) difference in brain weight. Ability to solve the extrapolation task was present in low-brain weight mice in generations 7-11 but declined with further selection. Investigation of extrapolation ability in mice with different chromosomal anomalies demonstrated that animals with Robertsonian translocations Rb(8,17) 1lem and Rb(8,17) 6Sic were capable of solving this task in a statistically significant majority of cases, while mice with fusion of other chromosomes, as well as CBA normal karyotype mice, performed no better than expected by chance. Mice with two types of partial trisomies and animals homo- and heterozygous for translocations were also tested. Although mice with T6 trisomy performed no better than expected by chance, animals with trisomy for a chromosome 17 fragment solved the task successfully. Thus, a genetic component underlying the ability to solve the extrapolation task was demonstrated in three animal species. The extrapolation task in animals is considered to reveal a general capacity for elementary reasoning. The genetic basis of this capacity is very complex.
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SYLVAIN GAGNON, F. R. A. N. C. O. I. S. Y. D. O. R. E. (1993). Search behavior of dogs (Canis familiaris) in invisible displacement problems. Anim Learn. & Behav., 21(3), 246–254.
Abstract: Gagnon and Dor (1992) showed that domestic dogs are able to solve a Piagetian object permanence
task called the invisible displacement problem. A toy is hidden in a container which is
moved behind a screen where the toy is removed and left. Dogs make more errors in these problems
than they do in visible displacement tests, in which the object is hidden directly behind
the target screen. In Experiment 1, we examinedcomponents ofthe standard procedure of invisible
displacements that may make encoding or retention of the hiding location more difficult than
it is in visible displacements. In Experiment 2, we compared dogs performances in visible and
invisible displacement problems when delays of 0, 10, and 20 sec were introduced between the
objects final disappearance and the subjects release. The results revealed that dogs poorer performance
in invisible displacement tests is related to the complex sequence of events that have
to be encoded or remembered as well as to a difficulty in representing the position change that
is signaled, but not directly perceived.
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RÖHRS, M., & EBINGER, P. (1993). Progressive und regressive Hirngrößenveränderungen bei Equiden. Z zool Syst Evolut forsch, 31, 233–239.
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Schuhmann K,. (1993). Untersuchung zur Sozialstruktur des persischen Wildesels. Doctoral thesis, , Freiburg.
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