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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 The Journal of Wildlife Management Abbreviated Journal Jour. Wild. Mgmt.
Volume n/a Issue n/a Pages
Keywords (up) 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
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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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Author Haring, H.
Title Development, level and prospects of the german horse breeding Type Journal Article
Year 2005 Publication Zuechtungskunde Abbreviated Journal Zuechtungskunde
Volume 77 Issue 6 Pages 490-495
Keywords (up) Breeding program; Breeding/Member association; Change of structure; Estimation of breeding values; Fédération Equestre Nationale (FN)/German Equestrian Federation; Step of selection; Equidae; Equus caballus
Abstract The economic impact of the horses of the Federal Republic of Germany has gone up, the statistic numerals verify obviously that Germany took pride of place in Europe in terms of numbers of riders as well as numbers of horses. Successes of German branded horses let their breeders reach the summit worldwide. The carefully agreed breeding programme connects practical cognitions with those of science and permits the leading breeding areas unobstructed space to set their own priorities. Globalisation and rised demand of customers forces breeding associations towards a far-reaching reorganisation because just large powerful institutions can meet these requirements. An end of this process, which scarcely has just begun, cannot yet be conceivable seen. – Eugen Ulmer KG, Stuttgart.
Address Deutsche Reiterliche Vereinigung e. V., 48229 Warendorf, Germany
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ISSN 00445401 (Issn) ISBN Medium
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Notes Cited By (since 1996): 1; Export Date: 21 April 2007; Source: Scopus; Language of Original Document: German; Correspondence Address: Haring, H.; Deutsche Reiterliche Vereinigung e. V. 48229 Warendorf, Germany; email: Hharing@fn-dokr.de Approved no
Call Number refbase @ user @ Serial 791
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Author Dubois, C.; Manfredi, E.; Ricard, A.
Title Optimization of breeding schemes for sport horses Type Journal Article
Year 2008 Publication Livestock Science Abbreviated Journal
Volume 118 Issue 1-2 Pages 99-112
Keywords (up) Breeding scheme; Horse; Jumping; Optimization; Genetic trend, Multistage selection
Abstract A selection scheme for jumping sport horses is modelled with four stages of selection for males and one stage for females. The selection objective included three traits: conformation and gaits (CG, weighted 20%), competition jumping (CJ, weighted 60%) and a third trait (TT, weighted 20%) such as sperm quality or orthopaedic status. The first selection stage is based on knowledge of the pedigree with the aim of selecting horses suitable for CG test (at 3 years old) and CJ test (at 5 years old). The second stage includes the horse's own performance with respect to CG and CJ with the aim of selecting horses suitable for the TT test. The third stage is the selection of a limited number of males who are allowed to reproduce. The fourth stage (at 12 years old) takes into account the results of the horse's progeny. Females are selected in one step, whatever the number of performances measured at 5 years old. The annual genetic response was 9.4% genetic standard deviation of the objective, 2.6% for CG, 9.0% for CJ and 1.5% for TT. Results showed that selection by progeny testing did not contribute much to genetic response (12% of progeny issued from proven sires), the female pathway represented 26% of genetic response, TT was difficult to improve when the genetic correlation was unfavourable (- 0.6% genetic standard deviation for - 0.20 genetic correlation), and should consequently be directed towards the use of molecular markers. When compared with a selection scheme involving a station test, genetic response was the same if the breeding values used for selection before entering the station test took into account the results of the relatives for CJ and CG. This revealed the importance of an extensive performance test (like for competition performance) when designing breeding schemes for sport horses.
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ISSN 1871-1413 ISBN Medium
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Notes Approved no
Call Number Equine Behaviour @ team @ Serial 4759
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Author Dugatkin, L.A.; Mesterton-Gibbons, M.
Title Cooperation among unrelated individuals: reciprocal altruism, by-product mutualism and group selection in fishes Type Journal Article
Year 1996 Publication Biosystems Abbreviated Journal Biosystems
Volume 37 Issue 1-2 Pages 19-30
Keywords (up) By-product mutualism; Cooperative behavior; Fish; Reciprocal altruism; Trait-group selection
Abstract Cooperation among unrelated individuals can evolve not only via reciprocal altruism but also via trait-group selection or by-product mutualism (or some combination of all three categories). Therefore the (iterated) prisoner's dilemma is an insufficient paradigm for studying the evolution of cooperation. We replace this game by the cooperator's dilemma, which is more versatile because it enables all three categories of cooperative behavior to be examined within the framework of a single theory. Controlled studies of cooperation among fish provide examples of each category of cooperation. Specifically, we describe reciprocal altruism among simultaneous hermaphrodites that swap egg parcels, group-selected cooperation among fish that inspect dangerous predators and by-product mutualism in the cooperative foraging of coral-reef fish.
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Notes Approved no
Call Number refbase @ user @ Serial 481
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Author Feh, C.; Munkhtuya, B.
Title Male infanticide and paternity analyses in a socially natural herd of Przewalski`s horses: Sexual selection? Type Journal Article
Year 2008 Publication Behavioural Processes Abbreviated Journal Behav. Process.
Volume 78 Issue 3 Pages 335-339
Keywords (up) DNA paternity analysis; Human disturbance; Male infanticide; Przewalski's horse (Equus ferus przewalskii); Sexual selection
Abstract The sexual selection hypothesis explains infanticide by males in many mammals. In our 11-year study, we investigated this hypothesis in a herd of Przewalski's horses where we had witnessed infanticidal attacks. Infanticide was highly conditional and not simply linked to takeovers. Attacks occurred in only five of 39 cases following a takeover, and DNA paternity revealed that, although infanticidal stallions were not the genetic fathers in four cases out of five, stallions present at birth did not significantly attempt to kill unrelated foals. Infanticide did not reduce birth intervals; only in one case out of five was the infanticidal stallion, the father of the next foal; mothers whose foals were attacked subsequently avoided associating with infanticidal stallions. Therefore, evidence for the sexual selection hypothesis was weak. The “human disturbance” hypothesis received some support, as only zoo bred stallions which grew up in unnatural social groups attacked foals of mares which were pregnant during takeovers.
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Call Number Equine Behaviour @ team @ Serial 4632
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Author Sanga, U.; Provenza, F.D.; Villalba, J.J.
Title Transmission of self-medicative behaviour from mother to offspring in sheep Type Journal Article
Year 2011 Publication Animal Behaviour Abbreviated Journal Anim. Behav.
Volume 82 Issue 2 Pages 219-227
Keywords (up) feeding; food selection; Ovis aries; polyethylene glycol; sheep; tannins
Abstract Herbivores challenged by diets with high concentrations of tannins learn by individual experience to self-select medicinal compounds such as polyethylene glycol (PEG), which neutralizes the negative postingestive effects of tannins. We investigated the transmission of this acquired self-medicative behaviour from mother to offspring. One group of ewes (experienced, N = 8) was conditioned to associate the beneficial effects of PEG after consuming a tannin-rich diet. Ewes ingested a meal of high-tannin food and were then offered PEG. Subsequently, ewes ingested the same tannin-rich meal and were then offered a food (grape pomace; control) that did not have the medicinal effects of PEG. After conditioning, the experienced group and a naïve group of ewes (N = 8) were given a choice between the high-tannin food, PEG and grape pomace. Experienced ewes showed higher intake and preference for PEG than did naïve ewes (P < 0.05). Subsequently, experienced and naïve ewes with their naïve lambs, as well as a group of naïve lambs without their mothers (N = 8), were exposed to the tannin-rich diet, PEG and grape pomace. Lambs were then tested for their ability to self-medicate with PEG by offering them a choice between the tannin-rich diet, PEG and grape pomace. Lambs from experienced and naïve mothers showed a higher preference for PEG than did lambs exposed without their mothers (P = 0.05). Thus, the presence of the mother (experienced or naïve) was important for naïve lambs to learn about the medicinal benefits of PEG. We conclude that the mother's presence per se may increase the efficiency of creating new knowledge, such as preference for a medicine, within a group, beyond transmitting and maintaining this knowledge across generations.
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ISSN 0003-3472 ISBN Medium
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Notes Approved no
Call Number Equine Behaviour @ team @ Serial 5406
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Author De Cremer, D.; van Dijk, E.
Title Leader--Follower Effects in Resource Dilemmas: The Roles of Leadership Selection and Social Responsibility Type Journal Article
Year 2008 Publication Group Processes Intergroup Relations Abbreviated Journal
Volume 11 Issue 3 Pages 355-369
Keywords (up) followers, leadership selection, resource allocations, resource dilemmas, social responsibility
Abstract Previous research on the allocation of scarce resources shows that when people are assigned labels of leader or follower in their group, leaders allocate more of the scarce resources to themselves than followers do. In three laboratory studies, we examine the idea that how people are selected for the leader role (i.e. election or appointment) determines whether leaders take more or equal shares (relative to followers) from a common resource. In a first experiment, we show that participants were more accepting of norm violating behavior by an appointed versus elected leader. In a second experiment, we show that when participants were assigned to a leader or follower role, allocations of appointed leaders differed significantly from those of elected leaders and followers, whereas there was no difference between the two latter conditions. Moreover, elected leaders were shown to feel more social responsibility than both appointed leaders and followers. In a final experiment, we show that when participants were primed with the concept of social responsibility (relative to a neutral condition) no difference in allocations between appointed and elected leaders emerged.
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Call Number Equine Behaviour @ team @ Serial 4805
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Author Scott, L.D.
Title Living donor liver transplant--is the horse already out of the barn? Type Journal Article
Year 2006 Publication The American Journal of Gastroenterology Abbreviated Journal Am J Gastroenterol
Volume 101 Issue 4 Pages 686-688
Keywords (up) Guidelines; Humans; Informed Consent; Liver Transplantation/*ethics; Living Donors/*ethics; Patient Selection; Risk Factors; Tissue and Organ Harvesting; Truth Disclosure
Abstract
Address Division of Gastroenterology & Hepatology, The University of Texas Medical Branch, Galveston, Texas, USA
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Language English Summary Language Original Title
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ISSN 0002-9270 ISBN Medium
Area Expedition Conference
Notes PMID:16635214 Approved no
Call Number Serial 1874
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Author Stock, K.F.; Distl, O.
Title Prediction of breeding values for osseous fragments in fetlock and hock joints, deforming arthropathy in hock joints, and pathologic changes in the navicular bones of Hanoverian Warmblood horses Type Journal Article
Year 2005 Publication Livestock Production Science Abbreviated Journal
Volume 92 Issue 1 Pages 77-94
Keywords (up) Hanoverian Warmblood horse; Radiological status; Breeding values; Response to selection
Abstract The results of a standardised radiological examination of 5928 Hanoverian Warmblood horses selected for sale at auction were used to predict relative breeding values (RBV) in the 23,662 horses included in the last four generations of the probands' pedigrees. The distribution of the RBV was investigated in the whole four-generation pedigree, in the probands and in those stallions that contributed at least three offspring to the probands. The RBV of the probands' sires were further compared with the officially published performance-based relative breeding values, i.e., total indices dressage (TID) and jumping (TIJ). The sires' level of dressage indices was considerably higher (mean TID=110) than of the jumping indices (mean TIJ=98). Total indices radiographic findings (TIR) were calculated for the sires with varying weighting given to the individual RBV. In each case, this resulted in a mean TIR of 99. Finally, total indices were derived from TIR and TID and/or TIJ in order to develop different selection schemes for all-purpose breeding and for breeding focused on dressage and show jumping. All breeding values under consideration increased by between 1% and 19% when radiographic findings were weighted with between 30% and 60% complementary to the corresponding performance parameters, and when only sires were selected with above average total indices. At the same time, the prevalences of the radiographic findings investigated here were lowered by up to 10% each. When only one radiographic finding was considered at a time, the maximum attainable response to selection was a 16-23% increase in the relative breeding values and a relative decrease in prevalences of radiographic findings of between 31% and 52%. The results of this study indicate that it is possible in horse breeding to consider simultaneously health and performance traits. Medical data should be included in the prediction of breeding values in order to improve the radiological status of today's riding horses.
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Notes Approved no
Call Number refbase @ user @ Serial 3953
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Author von Borstel, U.U.K.; Duncan, I.J.H.; Lundin, M.C.; Keeling, L.J.
Title Fear reactions in trained and untrained horses from dressage and show-jumping breeding lines Type Journal Article
Year 2010 Publication Applied Animal Behaviour Science Abbreviated Journal Appl. Anim. Behav. Sci.
Volume 125 Issue 3–4 Pages 124-131
Keywords (up) Horse; Fear; Habituation; Riding; Training; Genetic selection
Abstract Horses’ fear reactions are hazardous to both horses and human beings, but it is not clear whether fear is influenced more by training or by other factors such as genetics. The following study was designed to detect differences between young, untrained (U) and older, well-trained (T) horses of dressage (D), show-jumping (J), and mixed (M) genetic lines with regard to intensity of reaction and ease of habituation to a frightening stimulus. In five consecutive trials, 90 horses were exposed to a standardized fear-eliciting stimulus where intensity and duration of the reactions were recorded. Repeated measures analysis showed that flight reactions by J were less intense (p < 0.05) than those by D or M regardless of training status or age. Habituation to the stimulus over time was not significantly (p > 0.1) different between the disciplines, as indicated by similar slopes for all measurements, but reaction vigour declined faster for T than for U. These findings indicate that there may be a genetic basis for less strong, though not shorter-lasting, fear reactions in J compared to D or M lines of horses. Research including the estimation of genetic correlations between traits related to fearfulness and to performance would be required to verify this assumption.
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ISSN 0168-1591 ISBN Medium
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Notes Approved no
Call Number Equine Behaviour @ team @ Serial 5643
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