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Author Boyce, P.N.; McLoughlin, P.D.
Title (down) 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 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
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ISSN 0022-541x ISBN Medium
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Notes https://doi.org/10.1002/jwmg.21995 Approved no
Call Number Equine Behaviour @ team @ Serial 6642
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Author Deutsch, J.; Lee, P.
Title (down) Dominance and feeding competition in captive rhesus monkeys Type Journal Article
Year 1991 Publication 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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Notes Approved no
Call Number refbase @ user @ Serial 813
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Author Kaminski, J.; Pitsch, A.; Tomasello, M.
Title (down) Dogs steal in the dark Type Journal Article
Year 2013 Publication Abbreviated Journal Animal Cognition
Volume 16 Issue 3 Pages 385-394
Keywords Domestic dog; Social cognition; Perspective taking; Competition
Abstract All current evidence of visual perspective taking in dogs can possibly be explained by dogs reacting to certain stimuli rather than understanding what others see. In the current study, we set up a situation in which contextual information and social cues are in conflict. A human always forbade the dog from taking a piece of food. The part of the room being illuminated was then varied, for example, either the area where the human was seated or the area where the food was located was lit. Results show that dogs steal significantly more food when it is dark compared to when it is light. While stealing forbidden food the dog’s behaviour also depends on the type of illumination in the room. Illumination around the food, but not the human, affected the dogs’ behaviour. This indicates that dogs do not take the sight of the human as a signal to avoid the food. It also cannot be explained by a low-level associative rule of avoiding illuminated food which dogs actually approach faster when they are in private. The current finding therefore raises the possibility that dogs take into account the human’s visual access to the food while making their decision to steal it.
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Publisher Springer-Verlag Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1435-9448 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Equine Behaviour @ team @ Serial 5669
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Author Duncan, P.; Foose, T. J.; Gordon, I. J.; Gakahu,C. G.; Lloyd, M.
Title (down) 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 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 Voelkl, B.; Huber, L.
Title (down) Common marmosets (Callithrix jacchus) do not utilize social information in three simultaneous social foraging tasks Type Journal Article
Year 2007 Publication Animal Cognition Abbreviated Journal Anim. Cogn.
Volume 10 Issue 2 Pages 149-158
Keywords Marmosets – Social foraging – Social information – Food competition
Abstract Abstract  Social foraging is suggested to increase foraging efficiency, as individuals might benefit from public information acquired by monitoring the foraging activities of other group members. We conducted a series experiments with captive common marmosets (Callithrix jacchus) to investigate to what extent marmosets utilize social information about food location when foraging simultaneously with conspecifics. Subjects were confronted with dominant and subordinate demonstrators in three experiments which differed in the amount of information about food location available to the demonstrators. In all three experiments, the focal subjects` performance in the social condition was not enhanced in comparison to a non-social control condition. Because we could rule out kleptoparasitism and aggressive displacements as explanations, we argue that the subjects tendency for scramble competition by avoiding others and dispersing over the foraging area seems to inhibit or mask the acquisition of social information about the location of rewarded patches.
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Notes Approved no
Call Number Admin @ knut @ Serial 4220
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Author Bräuer, J.; Call, J.; Tomasello, M.
Title (down) Chimpanzees do not take into account what others can hear in a competitive situation Type Journal Article
Year 2008 Publication Animal Cognition Abbreviated Journal Anim. Cogn.
Volume 11 Issue 1 Pages 1435-9448
Keywords Social cognition – Food competition – Perspective taking
Abstract Chimpanzees (Pan troglodytes) know what others can and cannot see in a competitive situation. Does this reflect a general understanding the perceptions of others` In a study by Hare et al. (2000) pairs of chimpanzees competed over two pieces of food. Subordinate individuals preferred to approach food that was behind a barrier that the dominant could not see, suggesting that chimpanzees can take the visual perspective of others. We extended this paradigm to the auditory modality to investigate whether chimpanzees are sensitive to whether a competitor can hear food rewards being hidden. Results suggested that the chimpanzees did not take what the competitor had heard into account, despite being able to locate the hiding place themselves by the noise.
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Notes Approved no
Call Number Admin @ knut @ Serial 4218
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Author Trillmich, F.; Rehling, A.
Title (down) Animal Communication: Parent-Offspring Type Book Chapter
Year 2006 Publication 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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Publisher Elsevier Place of Publication Oxford Editor Keith Brown
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN ISBN 9780080448541 Medium
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Notes Approved no
Call Number Equine Behaviour @ team @ Serial 4642
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