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Kirkpatrick, J. F., & Turner, J. W. J. (1986). Comparative reproductive biology of North American feral horses. J. Equine Vet. Sci., 6, 224–230.
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Mayes, E., & Duncan, P. (1986). Temporal patterns of feeding behaviour in free-ranging horses. Behav., 96, 105–129.
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Polley, L. (1986). Strongylid parasites of horses: experimental ecology of the free-living stages on the Canadian prairie. Am J Vet Res, 47(8), 1686–1693.
Abstract: Each month for a 1-year period (October through September), equine fecal masses containing eggs of strongylid nematodes were placed outdoors on small grass plots in Saskatchewan, Canada. Thereafter, feces and grass from the plots were sampled after intervals of 1 week or longer, and the strongylid eggs and larvae recovered were counted. These observations were made over a 2-year period. Development of eggs to infective larvae occurred in all experiments, except those established in October, December, and January. Infective larvae from experiments set up in April through September survived that winter. During the summer, there was a gradual build up of infective larvae in the fecal masses, which reached a peak in August and September and then decreased into the winter. These results are discussed in the context of the control of strongylid parasites of horses on the Canadian prairie and in other areas of the world with a similar climate and similar horse management practices.
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Takai, S., Narita, K., Ando, K., & Tsubaki, S. (1986). Ecology of Rhodococcus (Corynebacterium) equi in soil on a horse-breeding farm. Vet Microbiol, 12(2), 169–177.
Abstract: The ecology of Rhodococcus (Corynebacterium) equi in soil was studied on a horse-breeding farm. R. equi was cultured from soil at a depth of 0, 10, and 20 cm on the six sites of the farm at monthly intervals for 10 months from March to December of 1983. The highest numbers of R. equi were found in the surface soil. The mean number of bacteria in soil samples at every depth increased remarkably from 0 or 10(2) to 10(4) colony-forming units (CFU) g-1 of soil in the middle of April, and later decreased gradually. R. equi inoculated into six soil exudate broths prepared from surface soils at separate sites yielded suspensions with different optical densities, indicating differences in growth. The distribution of serotypes in the soil was similar to that in the horses on the farm. These findings indicated that R. equi could multiply in the soil and flourish in the cycle existing between horses and their soil environment.
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Crans, W. J., McNelly, J., Schulze, T. L., & Main, A. (1986). Isolation of eastern equine encephalitis virus from Aedes sollicitans during an epizootic in southern New Jersey. J Am Mosq Control Assoc, 2(1), 68–72.
Abstract: Eastern equine encephalitis virus (EEE) was isolated from the salt marsh mosquito, Aedes sollicitans, collected from coastal areas of New Jersey on 3 occasions during the late summer and fall of 1982. The isolations were made at a time when local Culiseta melanura were either undergoing a population increase or exhibiting high levels of EEE virus. Although no human cases were reported during the epizootic period, the data lend support to the hypothesis that Ae. sollicitans is capable of functioning as an epidemic vector in the coastal areas of New Jersey where human cases of EEE have been most common.
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Cynx, J., Hulse, S. H., & Polyzois, S. (1986). A psychophysical measure of pitch discrimination loss resulting from a frequency range constraint in European starlings (Sturnus vulgaris). J Exp Psychol Anim Behav Process, 12(4), 394–402.
Abstract: Earlier research (Hulse & Cynx, 1985) revealed that a number of species of songbirds acquired a pitch discrimination between rising and falling sequences in an arbitrarily defined training range of frequencies, but then failed to generalize the discrimination to new frequency ranges--a frequency range constraint. The two experiments here provide a psychophysical estimate of how pitch discrimination deteriorated in one species as sequences were stepped out from the training range. The gradient showing loss of discrimination was much sharper than would have been anticipated by stimulus generalization or the training procedures, and appeared unaffected by the removal of rising and falling frequency information. The frequency range constraint and its psychophysical properties have implications both for the analysis of birdsong and the study of animal cognition.
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Flavell JH. (1986). The development of children's knowledge about the appearance-reality distinction. Am. Psychol., 41, 418.
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Kortlandt A. (1986). The use of tools by wild-living chimpanzees and earliest hominids. J. Hum. Evol.,, 15, 77.
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Heird, J. C., Whitaker, D. D., Bell, R. W., Ramsey, C. B., & Lokey, C. E. (1986). The effects of handling at different ages on the subsequent learning ability of 2-year-old horses. Appl. Anim. Behav. Sci., 15(1), 15–25.
Abstract: Forty weanling Quarter Horses, from the Pitchfork Ranch, Dickens, Texas, were randomly assigned to one of five groups based on the amount of handling they would receive. The five groups were: (1) limited handling; (2) 1 week of handling; (3) 2 weeks of handling; (4) 3 weeks of handling; (5) continuous handling for 18 months. As 2-year-olds, the horses were tested in a simple place-learning T-maze after being preconditioned. A maximum of 30 daily trials were conducted for 20 consecutive days, with feed location alternating between sides on successive days. If a horse met the criterion of 11 out of 12 correct responses with 8 correct responses being consecutive, it was retired without completing the 30 trials. Group 1 made fewer correct responses during the 20 days than any other group except Group 3. All groups achieved learning by Day 10, but the most-handled group reached a consistently higher percentage of correct responses earlier than the less-handled groups. Group 5, the group receiving the most handling, was the least emotional, as determined by the animals' reactivity to a novel stimulus, and received the highest scores for trainability after being ridden. Preconditioning trainability scores, or estimates of the horses' ability to learn prior to conditioning and testing, tended to predict maze-learning ability. These scores were also significantly correlated with post-maze training scores.
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Liang, K. - Y., & Zeger, S. L. (1986). Longitudinal data analysis using generalized linear models. Biometrika, 73(1), 13–22.
Abstract: This paper proposes an extension of generalized linear models to the analysis of longitudinal data. We introduce a class of estimating equations that give consistent estimates of the regression parameters and of their variance under mild assumptions about the time dependence. The estimating equations are derived without specifying the joint distribution of a subject's observations yet they reduce to the score equations for niultivariate Gaussian outcomes. Asymptotic theory is presented for the general class of estimators. Specific cases in which we assume independence, m-dependence and exchangeable correlation structures from each subject are discussed. Efficiency of the pioposecl estimators in two simple situations is considered. The approach is closely related to quasi-likelihood.
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