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Penzhorn Bl,. (1984). A long – term study of social organisation and bhabiour of Cape mountain zebras. Z. Tierpsychol., 64, 97–146.
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SCHILDER MBH et al,. (1984). A quantitative analysis of facial expressions in the plains zebra. Z. Tierpsychol., 66, 11–32.
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Penzhorn, B. L. (1984). A Long-term Study of Social Organisation and Behaviour of Cape Mountain Zebras Equus zebra zebra. Z. Tierpsychol., 64(2), 97–146.
Abstract: Abstract and Summary 1. The social structure of Cape mountain zebras consists of breeding herds and bachelor groups. The breeding herds, which comprise 1 stallion, 1–5 mares and their offspring, remain stable over many years. When the stallion is displaced by another the mares usually remain together, although some herds split up. A dominance hierarchy exists, but leadership is not confined to the dominant member. Foals leave their maternal herds at a mean age of 21.9 months. The herd stallion tries to prevent foals from leaving the herd.2. Bachelor groups are not as rigidly structured as breeding herds but core groups could be identified through a Principal Components Analysis. Family ties may be important in the establishment of core groups. Bachelors succeed in becoming herd stallions when ca. 5 years old.3. The recipient of a threat moving away seems to be an adequate response. Submissive behaviour was only recorded in bachelors. Fighting is rare, with biting as an important element. Compared to plains zebras, sounds made in communication are limited. Social grooming mainly occurs between mare and foal. Grooming intention movements may be an appeasement gesture.4. An oestrus mare assumes a characteristic posture. Flehmen occurs. Urine and faeces of oestrus mares are often marked by the stallion. This cannot be explained functionally and is not restricted to eliminations of oestrus mares. Penis erection and jerking by resting stallions could serve as a warning signal, but may be masturbatory.5. The herd stallion actively herds members of his herd and reduces intraherd antagonism by means of threats. He usually leads when the herd goes to drink and brings up the rear when the herd moves away from danger.6. Play was rarely recorded.7. A challenge ritual is performed when herd stallions meet. When challenged by a herd stallion, a bachelor is submissive.8. Foals initially remain close to their mothers and have to learn the correct orientation when suckling. A single adoption was recorded.9. Individuals apparently recognise each other after long periods.10. Cape mountain zebras react to alarm signals of antelopes.11. The greater part of the day is devoted to grazing. A significantly greater percentage of the day is spent resting in winter than in summer. Cape mountain zebras mainly stand while resting, but resting in sternal or lateral recumbency also occurs. Defaecation and urination occurs throughout the day with no definite peaks.12. Grooming consists of localized muscle contractions, shaking, striking one part of the body against another or against the ground, rubbing, dust-bathing, scratching and nibbling.13. In cold weather, Cape mountain zebras seek shelter in wooded kloofs. Zusammenfassung * 1Bergzebras bilden Familien und Junggesellengruppen. Familien bestehen aus einem Hengst, 1–5 Stuten und deren Nachwuchs. Harems bleiben jahrelang unverändert. Wird der Hengst verdrängt, so bleiben die Stuten meist zusammen. Es besteht eine Rangordnung, doch führt nicht nur das dominante Tier. Fohlen verlassen die Familie mit durchschnittlich 21,9 Monaten. Der Familienhengst versucht, die Fohlen am Weggehen zu hindern. * 2Junggesellengruppen sind nicht so fest strukturiert wie die Familien, doch lassen sich Kerngruppen durch Hauptkomponentenanalyse identifizieren. Familienbeziehungen können für das Entstehen soldier Kerngruppen wichtig sein. Junggesellen können im Alter von ungefähr 5 Jahren Familienhengste werden. * 3Flucht ist offenbar die ausreichende Reaktion auf Drohung. Unterwürfiges Verhalten wurde nur bei Junggesellen beobachtet. Kämpfe sieht man selten. Bergzebras haben weniger Kommunikationslaute als Steppenzebras. Soziale Hautpflege findet meist zwischen Stute und Fohlen statt. PflegeIntentionsbewegungen können zur Streitschlichtung benutzt werden. * 4Rossige Stuten nehmen eine charakteristische Stellung ein. Flehmen kommt vor. Harn und Kot rossiger Stuten werden oft vom Hengst markiert. Erektion des Penis mit Zuckungen beim ruhenden Hengst kann entweder als Warnsignal oder als Masturbation gedeutet werden. * 5Der Hengst herdet die Mitglieder seiner Familie und bremst innerfamiliäre Aggression durch Drohen. Gewöhnlich führt er die Familie zur Tränke und verläßt als Letzter die Gefahrenzone. * 6Spielen wurde selten beobachtet. * 7Wenn Familienhengste sich treffen, findet ein Herausforderungs-Ritual statt. Junggesellen reagieren unterwürfig, wenn sie so herausgefordert werden. * 8Fohlen bleiben anfangs nahe bei der Mutter. Sie müssen die richtige Orientierung beim Säugen erlernen. Eine Adoption wurde registriert. * 9Individuen scheinen sich nach langer Zeit wiederzuerkennen. * 10Bergzebras reagieren auf die Alarmsignale von Antilopen. * 11Der größte Teil des Tages wird zum Grasen gebraucht. Im Winter gibt es signifikant längere Ruheperioden als im Sommer. Bergzebras ruhen meist stehend. Exkremente werden den ganzen Tag über ausgeschieden. Zur Körperpflege gehören örtliche Muskelkontraktionen, Schütteln, Schlagen eines Körperteils gegen einen anderen oder gegen den Boden, Reiben, Staubbaden, Kratzen und Knabbern. * 12Bei kaltem Wetter suchen Bergzebras in bewaldeten Schluchten Schutz.
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Barton, M. D., & Hughes, K. L. (1984). Ecology of Rhodococcus equi. Vet Microbiol, 9(1), 65–76.
Abstract: A selective broth enrichment technique was used to study the distribution of Rhodococcus equi in soil and grazing animals. Rhodococcus equi was isolated from 54% of soils examined and from the gut contents, rectal faeces and dung of all grazing herbivorous species examined. Rhodococcus equi was not isolated from the faeces or dung of penned animals which did not have access to grazing. The isolation rate from dung was much higher than from other samples and this was found to be due to the ability of R. equi to multiply more readily in dung. Delayed hypersensitivity tests were carried out on horses, sheep and cattle, but only horses reacted significantly. The physiological characteristics of R. equi and the nature of its distribution in the environment suggested that R. equi is a soil organism.
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Reichholf J,. (1984). Funktion und evolution des Streifenmusters bei den zebras. Säugetierk Mitt, 32, 89–95.
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Bard J,. (1984). Perch la zebra In:Kos;Revista di Cultura e Storia della. Sci Med, Nat e Humane, 1(6).
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Penzhorn Bl,. (1984). Observations on mortality of free – ranging Cape mountain zebras. S Afr Wildl Res, 14, 89–90.
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Boesch C, & Boesch H. (1984). Mental maps in wild chimpanzees: an analysis of hammer transports for nut cracking. Primates, 25, 160.
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Vogt H,. (1984). Quagga: DNA konserviert. Naturwiss Rdsch, 37, 327–328.
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Seyfarth, R. M., & Cheney, D. L. (1984). Grooming, alliances and reciprocal altruism in vervet monkeys. Nature, 308(5959), 541–543.
Abstract: Reciprocal altruism refers to the exchange of beneficial acts between individuals, in which the benefits to the recipient exceed the cost to the altruist. Theory predicts that cooperation among unrelated animals can occur whenever individuals encounter each other regularly and are capable of adjusting their cooperative behaviour according to experience. Although the potential for reciprocal altruism exists in many animal societies, most interactions occur between closely related individuals, and examples of reciprocity among non-kin are rare. The field experiments on vervet monkeys which we present here demonstrate that grooming between unrelated individuals increases the probability that they will subsequently attend to each others' solicitations for aid. Vervets appear to be more willing to aid unrelated individuals if those individuals have behaved affinitively toward them in the recent past. In contrast, recent grooming between close genetic relatives appears to have no effect on their willingness to respond to each other's solicitations for aid.
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