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Author Trillmich, F.; Rehling, A.
Title Animal Communication: Parent-Offspring Type Book Chapter
Year 2006 Publication (up) Encyclopedia of Language & Linguistics Abbreviated Journal
Volume Issue Pages 284-288
Keywords Begging Strategies; Communication; Competition; Feeding Strategies; Fitness; Parental Care; Parent-Offspring Conflict; Recognition; Sibling Conflict
Abstract Parent-offspring communication has evolved under strong selection to guarantee that the valuable resource of parental care is expended efficiently on raising offspring. To ensure allocation of parental care to their own offspring, individual recognition becomes established in higher vertebrates when the young become mobile at a time when a nest site can no longer provide a safe cue to recognition. Such recognition needs to be established by rapid, sometimes imprinting-like, processes in animals producing precocial offspring. In parents, offering strategies that stimulate feeding and entice offspring to approach the right site have evolved. Such parental signals can be olfactory, acoustic, or visual. In offspring, begging strategies involve shuffling for the best place to obtain food – be this the most productive teat or the best position in the nest. This involves signals that make the offspring particularly obvious to the parent. Parents often feed young according to their signaling intensity but may also show favoritism for weaker offspring. Offspring signals also serve to communicate the continuing presence of the young and may thereby maintain brood-care behavior in parents. Internal processes in parents may end parental care irrespective of further signaling by offspring, thus ensuring that offspring cannot manipulate parents into providing substantially more care than is optimal for their own fitness.
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Corporate Author Thesis
Publisher Elsevier Place of Publication Oxford Editor Keith Brown
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 9780080448541 Medium
Area Expedition Conference
Notes Approved no
Call Number Equine Behaviour @ team @ Serial 4642
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Author Deutsch, J.; Lee, P.
Title Dominance and feeding competition in captive rhesus monkeys Type Journal Article
Year 1991 Publication (up) International Journal of Primatology Abbreviated Journal Int. J. Primatol.
Volume 12 Issue 6 Pages 615-628
Keywords female dominance – feeding competition – nutrition – stress
Abstract The feeding behavior of 16 adult female rhesus monkeys living in three captive social groups was observed. Estimates of relative food intake, feeding rate, and location of feeding in relation to food sources were compared between females of different dominance ranks. Higher-ranking females had greater access to feeding sites and were supplanted or threatened less frequently while feeding than subordinates. However, no consistent differences in estimates of total intake were found between females of high and females of low rank. The effects of dominance on feeding behavior were most pronounced in the group receiving the least food relative to estimates of overall group nutritional requirements. Higher-ranking females, both over the long term and during the study period, tended to produce more surviving offspring. The effects of dominance on reproductive performance appeared to be less related to food intake than to competitive and aggressive interactions, potentially resulting in higher levels of stress for subordinates.
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Publisher Place of Publication Editor
Language Summary Language Original Title
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Notes Approved no
Call Number refbase @ user @ Serial 813
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Author Wallin, L.; Strandberg, E.; Philipsson, J.
Title Genetic correlations between field test results of Swedish Warmblood Riding Horses as 4-year-olds and lifetime performance results in dressage and show jumping Type Journal Article
Year 2003 Publication (up) Livestock Production Science Abbreviated Journal
Volume 82 Issue 1 Pages 61-71
Keywords Horse; Performance test; Competition results; Animal model; Heritability; Genetic correlation
Abstract The main objective of this study was to estimate genetic correlations between traits of young sport horses (4 years old) evaluated in the Swedish Riding Horse Quality Test (RHQT) and later competition results in dressage and show jumping. The data comprised 3708 Warmblood horses born between 1968 and 1982 that had participated in the RHQT as 4-year-olds and 25[punctuation space]605 horses born between 1953 and 1995 with competition records. According to the criteria between 1206 and 1879 horses were common to this two files and were available for the estimations of the genetic correlations. Competition performance traits were cumulative points and cumulative placings received during a horse's lifetime, and a log10 transformation was used to achieve a more normal distribution of the data. Genetic correlations between gait traits scored in the RHQT and competition results in dressage were favourable, in the range 0.63-0.75, and between jumping traits scored in the RHQT and results in show jumping 0.83-0.93. Estimated heritabilities for gait and jumping traits scored in the RHQT were in the range 0.09-0.27 and 0.10-0.18, respectively. Estimated heritabilities for the cumulative points and cumulative placings in dressage and show jumping were 0.17/0.16 and 0.23/0.27, respectively. Thus, the results from the RHQT have proved to be useful for early genetic evaluation and selection of both mares and stallions for sport performance traits.
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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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ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number refbase @ user @ Serial 3956
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Author Huizinga, H.A.; Boukamp, M.; Smolders, G.
Title Estimated parameters of field performance testing of mares from the Dutch Warmblood riding horse population Type Journal Article
Year 1990 Publication (up) Livestock Production Science Abbreviated Journal
Volume 26 Issue 4 Pages 291-299
Keywords competition; genetic parameters; horse breeding; mares; performance test
Abstract The field performance testing (FPT) of mares of the Dutch Warmblood riding horse population is evaluated. Phenotypic and genetic parameters of scored traits are estimated and the genetic relationship with performance of half-sibs in dressage and jumping competition are estimated. Data from 1984 to 1987 are used, covering scores from 2023 at least 3-year-old mares. Seven subjectively scored traits are considered, walk, trot, canter, riding ability, character, jumping ability and total score. Analysis of data is according to a sire model. Variance and covariance components are estimated by Restricted Maximum Likelihood (REML) procedures. Estimates of heritability are moderately low for gaits (average 0.19), jumping ability (0.15) and total score (0.17) and extremely low for riding ability (0.03) and character (0.06). Dressage in competition is most correlated with riding ability (0.83) and is moderately correlated with total score (0.41) from FPT of mares. Jumping competition is most correlated with jumping ability (0.48) and not correlated with total score (0.05) from field test of mares. Some possible bias owing to previous knowledge and preselection is discussed. It is concluded that efficiency of present FPT of mares is limited for selection of broodmares for dressage and jumping ability in competition.
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Notes Approved no
Call Number refbase @ user @ Serial 3964
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Author Thoren Hellsten, E.; Viklund, A.; Koenen, E.P.C.; Ricard, A.; Bruns, E.; Philipsson, J.
Title Review of genetic parameters estimated at stallion and young horse performance tests and their correlations with later results in dressage and show-jumping competition Type Journal Article
Year 2006 Publication (up) Livestock Science Abbreviated Journal
Volume 103 Issue 1-2 Pages 1-12
Keywords Genetic parameters; Sport horse; Performance test; Competition; Dressage; Show-jumping
Abstract Results from performance tests and competitions of young horses are used by major European warmblood horse breeding associations for genetic evaluations. The aim of this review was to compare genetic parameters for various tests of young horses to assess their efficiency in selection for dressage and show-jumping. Improved understanding of genetic information across countries is also necessary, as foreign trade with semen is rapidly increasing. The review is based on inquiries to European breed associations and on (17) scientific publications available, which have analysed genetic parameters of young horse data and/or relationships between young and mature horse results in sport. Despite differences in testing methods of young horses, results for major horse populations were in good agreement. Specially designed young horse performance tests, including stallion tests, showed high heritabilities and high genetic correlations with later competition results. We recommend that test results are encouraged to be used across countries for genetic evaluation of imported stallions and semen. Short station tests are generally preferred when selecting stallions for both dressage and jumping traits, whereas competition data may be used when selecting for only one discipline. We also recommend that extensive field testing of young horses is encouraged and should include both genders.
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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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Area Expedition Conference
Notes Approved no
Call Number refbase @ user @ Serial 3951
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Author Duncan, P.; Foose, T. J.; Gordon, I. J.; Gakahu,C. G.; Lloyd, M.
Title Comparative nutrient extraction from forages by grazing bovids and equids: a test of the nutritional model of equid/bovid competition and coexistence Type Journal Article
Year 1990 Publication (up) Oecologia Abbreviated Journal Oecologia
Volume 84 Issue 3 Pages 411-418
Keywords Ruminant – Hind-gut fermenter – Intake – Digestion – Competition
Abstract Ruminants are unevenly distributed across the range of body sizes observed in herbivorous mammals; among extant East African species they predominate, in numbers and species richness, in the medium body sizes (10-600 kg). The small and the large species are all hind-gut fermenters. Some medium-sized hind-gut fermenters, equid perissodactyls, coexist with the grazing ruminants, principally bovid artiodactyls, in grassland ecosystems. These patterns have been explained by two complementary models based on differences between the digestive physiology of ruminants and hind-gut fermenters. The Demment and Van Soest (1985) model accounts for the absence of ruminants among the small and large species, while the Bell/Janis/Foose model accounts both for the predominance of ruminants, and their co-existence with equids among the medium-sized species (Bell 1971; Janis 1976; Foose 1982). The latter model assumes that the rumen is competitively superior to the hind-gut system on medium quality forages, and that hind-gut fermenters persist because of their ability to eat more, and thus to extract more nutrients per day from high fibre, low quality forages. Data presented here demonstrate that compared to similarly sized grazing ruminants (bovids), hind-gut fermenters (equids) have higher rates of food intake which more than compensate for their lesser ability to digest plant material. As a consequence equids extract more nutrients per day than bovids not only from low quality foods, but from the whole range of forages eaten by animals of this size. Neither of the current nutritional models, nor refinements of them satisfactorily explain the preponderance of the bovids among medium-sized ungulates; alternative hypotheses are presented.
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Notes from Professor Hans Klingels Equine Reference List Approved yes
Call Number Serial 1035
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Author Boyce, P.N.; McLoughlin, P.D.
Title Ecological Interactions Involving Feral Horses and Predators: Review with Implications for Biodiversity Conservation Type Journal Article
Year 2021 Publication (up) The Journal of Wildlife Management Abbreviated Journal Jour. Wild. Mgmt.
Volume n/a Issue n/a Pages
Keywords apparent competition; artificial selection; community ecology; conservation; feral horse (Equus ferus caballus); life history; predator-prey dynamics
Abstract ABSTRACT For many ecosystems, feral horses are increasingly becoming an important if not dominant component of ungulate biomass and hence influence on community dynamics. Yet we still know little of how horses contribute to key ecological interactions including predator-prey and indirect competitive relationships at a community level. Notably, feral species like horses can exhibit life-history traits that differ from that of native (mainly artiodactyl) herbivore competitors. Artificial selection for traits like increased, early, or extended reproduction that have yet to be reversed by natural selection, coupled with naturally selected differences in anatomy and behavior, in addition to unique management objectives for horses compared to other species, means that the dynamics of feral horse populations are not likely to align with what might be expected of other large herbivores. Unexpected population dynamics and inherent biological asymmetries between native ungulates and feral horses may therefore influence the former via direct competition for shared resources and through enemy-mediated interactions like apparent competition. In several localities feral horses now co-exist with multiple native prey species, some of which are in decline or are species at risk. Compounding risks to native species from direct or indirect competitive exclusion by horses is the unique nature and socio-political context of feral horse management, which tends towards allowing horse populations to be limited largely by natural, density-dependent factors. We summarize the inherent asymmetries between feral horse biology and that of other ungulate prey species with consequences for conservation, focusing on predator-prey and emerging indirect interactions in multi-prey systems, and highlight future directions to address key knowledge gaps in our understanding of how feral horses may now be contributing to the (re)structuring of food webs. Observations of patterns of rapid growth and decline, and associated skews in sex ratios of feral horse populations, indicate a heightened potential for indirect interactions among large ungulate prey species, where there is a prevalence of feral horses as preferred prey, particularly where native prey are declining. In places like western North America, we expect predator-prey interactions involving feral horses to become an increasingly important factor in the conservation of wildlife. This applies not only to economically or culturally important game species but also at-risk species, both predators (e.g., wolves [Canis lupus], grizzly bears [Ursus arctos]) and prey (e.g., woodland caribou [Rangifer tarandus caribou]), necessitating an ecological understanding of the role of horses in natural environments that goes beyond that of population control. ? 2021 The Wildlife Society.
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Publisher John Wiley & Sons, Ltd Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-541x ISBN Medium
Area Expedition Conference
Notes https://doi.org/10.1002/jwmg.21995 Approved no
Call Number Equine Behaviour @ team @ Serial 6642
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