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Author Ryder, O.A.
Title Przewalski's horse – putting the wild horse back in the wild Type Journal Article
Year 1988 Publication Oryx Abbreviated Journal Oryx
Volume 22 Issue Pages 154-157
Keywords Equidae genetics.
Abstract The Asian wild horse, or Przewalski's horse (Equus przewalskii), is believed to currently survive only in captivity. There are more than 660 individuals in over 70 zoological collections, and animals are available for reintroduction. The Przewalski's horse had been bred in captivity for 12 generations, and inbreeding has occurred. Genetic variability has been lost, and released animals will require acclimatization on or near release sites. In China, a program is under way for acclimatization, breeding, and release of wild horses, and plans are being made for a similar program in Mongolia. (LCA)
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Area Expedition Conference
Notes from Professor Hans Klingels Equine Reference List Approved yes
Call Number Serial 1537
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Author Black, J.M.
Title Preflight Signalling in Swans: A Mechanism for Group Cohesion and Flock Formation Type Journal Article
Year 1988 Publication Ethology Abbreviated Journal Ethology
Volume 79 Issue 2 Pages 143-157
Keywords
Abstract Abstract The preflight behaviour of whooper swans Cygnus cygnus and Bewick's swans Cygnus columbianus bewickii was examined to determine the adaptive significance of the ritual. Analysis of the preflight sequence revealed that the rate of signalling became significantly faster as the time of takeoff approached. This provides the first quantitative evidence that a threshold of excitability is responsible for triggering synchronised flight in social units. Two ultimate and two proximate factors that affect this threshold were uncovered. They are: 1) Maintaining proximity to partners—flight was delayed by birds with non-attentive mates and signalling lasted on average four times longer than those whose mates showed more interest. 2) Maintaining flock cohesiveness—birds which performed signals for longer periods while swimming among uninterested birds were successful in attracting followers 61% of the time. 3) The bird's feeding performance related to dominance status—less successful feeders (potentially hungry birds), flew after little time and few signals. 4) The type of feeding opportunity at the eventual destination—birds which flew to provided feeds (nutritious barley) spent less time performing preflight signals than when they flew to forage on grass fields.
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Corporate Author Thesis
Publisher Blackwell Publishing Ltd Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1439-0310 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Equine Behaviour @ team @ Serial 5315
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Author Leonard, M.L.; Horn, A.G.; Eden, S.F.
Title Parent-offspring aggression in moorhens Type Journal Article
Year 1988 Publication Behav. Ecol. Sociobiol. Abbreviated Journal
Volume 23 Issue Pages 265-270
Keywords
Abstract The purpose of this study was to explain parental aggression to offspring in the moorhen (Gallinula chloropus). Males and females did not feed different subsets of chicks. In addition, there was a positive correlation between feeding rates of each parent to a particular chick and the number of attacks (tousles) directed to that chick, contrary to what was expected if aggression served to divide the brood. In moorhens, large chicks outcompeted small chicks for parental feedings. However, adults were more aggressive to large chicks and as a result small chicks spent significantly more time closer to parents and received more feedings than large chicks. In 84% of broods every chick was attacked at least once, although large chicks were attacked more often than small chicks. The behaviour of chicks changed immediately after an attack (Table 2). Before an attack chicks were <1 m from the parents while after an attack they were >1 m. The apparent effect of parental aggression in moorhens is to reduce demands by chicks for feedings. Aggression appears to reduce sibling competition and to encourage chick independence.
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Notes 10.1007/Bf00302949 Approved no
Call Number Equine Behaviour @ team @ Serial 4905
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Author Clutton-Brock, T.H.; Green, D.; Hiraiwa-Hasegawa, M.; Albon, S.D.
Title Passing the buck: resource defence, lek breeding and mate choice in fallow deer Type Journal Article
Year 1988 Publication Behav. Ecol. Sociobiol. Abbreviated Journal
Volume 23 Issue Pages 281-296
Keywords
Abstract lsquoLekrsquo breeding systems, where males defend small, clustered mating territories, are thought to occur where the distribution of females is heavily clumped but males are unable to defend resources used by females. In this paper, we describe a breeding system in fallow deer where males are able to defend resources used by females but the most successful bucks instead defend small territories on a traditional mating ground; where the lek is sited in an area not heavily used by females at other times of year and is visited primarily by females in or close to oestrus; and where mating success on the lek is related to territory position and to male phenotype but not to the resources available on different lek territories. Comparisons with other ungulates suggest that lek breeding species fall into two groups: those where leks are regularly visited by herds of females many of which are not in oestrus and those, like fallow deer, where leks are visited primarily by oestrous females. In the latter species, it is unlikely that females visit the lek for ecological reasons.
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Notes 10.1007/Bf00300575 Approved no
Call Number Equine Behaviour @ team @ Serial 4882
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Author Whiten, A.; Byrne, R.W.
Title Tactical deception in primates Type Journal Article
Year 1988 Publication Behavioral and Brain Sciences Abbreviated Journal Behav. Brain Sci.
Volume 11 Issue 02 Pages 233-244
Keywords
Abstract ABSTRACT Tactical deception occurs when an individual is able to use an “honest” act from his normal repertoire in a different context to mislead familiar individuals. Although primates have a reputation for social skill, most primate groups are so intimate that any deception is likely to be subtle and infrequent. Published records are sparse and often anecdotal. We have solicited new records from many primatologists and searched for repeating patterns. This has revealed several different forms of deceptive tactic, which we classify in terms of the function they perform. For each class, we sketch the features of another individual's state of mind that an individual acting with deceptive intent must be able to represent, thus acting as a “natural psychologist.” Our analysis will sharpen attention to apparent taxonomic differences. Before these findings can be generalized, however, behavioral scientists must agree on some fundamental methodological and theoretical questions in the study of the evolution of social cognition.
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Corporate Author Thesis
Publisher Cambridge Journals Online Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1469-1825 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Equine Behaviour @ team @ Serial 5937
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Author Kirkpatrick, J. F.; Kasman, L. H.; Lasley,; B. L.; Turner, J. W. Jr.
Title Pregnancy Determination in Uncaptured Feral Horses Type Journal Article
Year 1988 Publication Journal of Wildlife Management Abbreviated Journal J Wildl Manag
Volume 52 Issue 2 Pages 305-308
Keywords
Abstract The urinary excretion of estrone sulfate ($\text{E}{1}\text{S}$) by 25 free-roaming feral horses (Equus caballus) was measured by radioimmunoassay applied to extracts of urine-soaked soil. Twelve of 15 mares having $\text{E}{1}\text{S}$ concentrations >1.0 mg/mg creatinine (x = 2.64 +- 1.02 [SD]) produced foals. All 10 mares with $\text{E}{1}\text{S}$ concentrations <1.0 mg/mg creatinine (x = 0.44 +- 0.26) did not foal. Extracting urine from soil and measuring $\text{E}{1}\text{S}$ and creatinine can be used to determine pregnancy in free-roaming feral horses without the stress of capture or immobilization.
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Notes Approved no
Call Number Equine Behaviour @ team @ Serial 2290
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Author Berger, J.; Cunningham, C.
Title Size-Related Effects on Search Times in North American Grassland Female Ungulates Type Journal Article
Year 1988 Publication Ecology Abbreviated Journal
Volume 69 Issue 1 Pages 177-183
Keywords no keywords available
Abstract Feeding and searching (&#61; vigilance) rates arise as a result of many interrelated factors including trophic level, diet, reproductive condition, sex, habitat, body mass, and potential predation pressure. Because of unique ecological conditions in which the confounding influences of all but two of these variables could be minimized, we examined the hypothesis that body mass alone accounts for interspecific differences in search times, and tested it with females of four sympatric native North American ungulates (Bison bison, Antilocapra americana, Ovis canadensis, and Odocoileus hemionus). When the effects of group size were controlled, smaller bodied species were more vigilant (per unit body mass) than larger ones. However, search times (ST) also scaled to body mass, and between 81 and 97&#37; of the ST variance was explained by either exponential or power functions. To remove the potential bias that predators exert different influences on species of varying size, search times of bison in areas with and without their major predator, wolves (Canis lupus), were contrasted; search times did not differ between sites. Our results highlight the importance of designing field research that controls for confounding variables prior to attempting to scale behavioral processes to ecological events. See full-text article at JSTOR
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Corporate Author Thesis
Publisher Ecological Society of America Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0012-9658 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Equine Behaviour @ team @ Serial 2233
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Author Westlin-van Aarde, L.M.; van Aarde, R. J.; Skinner, J. D.
Title Reproduction in female Hartmann's zebra Type Journal Article
Year 1988 Publication Journal of Reproduction and Fertility Abbreviated Journal J Reprod Fert
Volume 84 Issue Pages 505-511
Keywords zebra; reproduction; ovaries; seasonality; progesterone
Abstract Ovaries, fetuses and plasma were collected from zebra mares shot in the Etosha National Park in Namibia between 15 and 25 August 1983. Ovarian weight was affected by reproductive status and most of the non-pregnant mares were anoestrous. The number of follicles varied between individuals and only pro-oestrous/oestrous mares had follicles larger than 20 mm in diameter. The largest follicle in pregnant mares was only 9 mm in diameter. Corpora lutea and corpora albicantia were found in non-pregnant as well as pregnant mares: 4 pregnant mares had only corpora albicantia. The presence of secondary corpora lutea could not be confirmed in any of the pregnant mares. Implantation was estimated to occur at around 73 days of gestation, and most mares (84%) had conceived between November and April. Peripheral concentrations of plasma progesterone during pregnancy varied from 0·5 to 2·4 ng/ml.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
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Area Expedition Conference
Notes from Professor Hans Klingels Equine Reference List Approved yes
Call Number Serial 1705
Permanent link to this record
 

 
Author Penzhorn, B. L.; van der Merwe, N. J.
Title Testis size and onset of spermatogenesis in Cape mountain zebras (Equus zebra zebra) Type Journal Article
Year 1988 Publication Journal of Reproduction and Fertility Abbreviated Journal J Reprod Fert
Volume 83 Issue Pages 371-375
Keywords mountain zebra; testis size; spermatogenesis
Abstract Testis mass of adult Cape mountain zebra stallions (mean 70·0 g) was appreciably less than that of other zebra species and domestic horses. The histological appearance of the testes of 11-, 24- and 29-month-old colts was typically prepubertal. Spermatogenic activity of a 4-year-old stallion obtained at the end of summer was at a very low level, while a 4·5-year-old stallion obtained 6 weeks after the winter solstice showed a marked increase in spermatogenesis compared with the 4-year-old. Stallions 6·5-19 years of age collected in different seasons all showed active spermatogenesis.
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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Notes from Professor Hans Klingels Equine Reference List Approved yes
Call Number Serial 1463
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Author Schilder, M.B.H.
Title Dominance relationships between adult Plains zebra stallions in semi – captivity Type Journal Article
Year 1988 Publication Behaviour Abbreviated Journal Behaviour
Volume 104 Issue 3-4 Pages 300-319
Keywords
Abstract The relationships between 4-5 adult zebra stallions, living in a safari park, were investigated over a period of 5 years. Asymmetries in the distributions of a number of behaviours could be explained by adopting dominance as an intervening variable. Dominance in stallions was of a bipolar nature with on the one hand behaviours representing subordinance and defence, and on the other hand behaviours reinforcing and confirming dominance. Expression of formal dominance seems to play a minor role. The dyadic relationships of stallions differed as to the number of behaviours reflecting dominance relationships. Although often linear rank-orders could be constructed, these rank-orders were not necessarily identical. This means that the concept of dominance is of only limited value for describing relationships between zebra stallions.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes from Professor Hans Klingels Equine Reference List Approved yes
Call Number Serial 1564
Permanent link to this record