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Boissy, A. (1995). Fear and Fearfulness in Animals. The Quarterly Review of Biology, 70(2), 165–191.
Abstract: Persistence of individual differences in animal behavior in reactions to various environmental challenges could reflect basic divergences in temperament, which might be used to predict details of adaptive response. Although studies have been carried out on fear and anxiety in various species, including laboratory, domestic and wild animals, no consistent definition of fearfulness as a basic trait of temperament has emerged. After a classification of the events that may produce a state of fear, this article describes the great variability in behavior and in physiological patterns generally associated with emotional reactivity. The difficulties of proposing fearfulness-the general capacity to react to a variety of potentially threatening situations-as a valid basic internal variable are then discussed. Although there are many studies showing covariation among the psychobiological responses to different environmental challenges, other studies find no such correlations and raise doubts about the interpretation of fearfulness as a basic personality trait. After a critical assessment of methodologies used in fear and anxiety studies, it is suggested that discrepancies among results are mainly due to the modulation of emotional responses in animals, which depend on numerous genetic and epigenetic factors. It is difficult to compare results obtained by different methods from animals reared under various conditions and with different genetic origins. The concept of fearfulness as an inner trait is best supported by two kinds of investigations. First, an experimental approach combining ethology and experimental psychology produces undeniable indicators of emotional reactivity. Second, genetic lines selected for psychobiological traits prove useful in establishing between behavioral and neuroendocrine aspects of emotional reactivity. It is suggested that fearfulness could be considered a basic feature of the temperament of each individual, one that predisposes it to respond similarly to a variety of potentially alarming challenges, but is nevertheless continually modulated during development by the interaction of genetic traits of reactivity with environmental factors, particularly in the juvenile period. Such interaction may explain much of the interindividual variability observed in adaptive responses.
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Niederhöfer, S. (2009). Stressbelastung bei Pferden in Abhängigkeit des Haltungssystems. Ph.D. thesis, Tierärztliche Hochschule Hannover, Hannover.
Abstract: Pferdegerechte Haltungssysteme spielen bei der heutigen Nutzung des Freizeit- oder Sportpartners Pferd eine wichtige Rolle, da naturnahe Haltungsbedingungen nur in seltenen Fällen zu realisieren sind. Sämtliche Aufstallungsformen müssen als Kompromiss angesehen werden und bieten somit Vor- und Nachteile. Die vorliegende Untersuchung verfolgte den Zweck, die Stressbelastung von Pferden in verschiedenen Haltungssystemen zu erfassen und vergleichend zu beurteilen. Während der von Mai 2006 bis Juli 2007 durchgeführten Versuche wurden 24 zwei- bis dreijährige Hannoveranerstuten für jeweils 4 Wochen in insgesamt 6 verschiedenen Haltungsformen aufgestallt. Die Haltungsvarianten beinhalteten die Einzelbox (Variante 1), die Einzelbox mit einem frei zugänglichem Paddock (Variante 2), die gemeinsame Haltung von zwei Pferden in zwei Boxen und einem angeschlossenen frei zugänglichem Auslauf (Variante 3) und die Gruppenhaltung von 6 Pferden in einer Mehrraumauslaufhaltung (Variante 4 – 6). Die Haltungsvariante 4 differierte von den Varianten 5 und 6 durch seinen ungegliederten Liegebereich. In den Variante 5 und 6 wurde der Liegebereich der Gruppenhaltung durch eine über die halbe Breite reichende Trennwand in zwei Bereiche unterteilt. Die Trennwand befand sich in Haltungsvariante 5 im rechten Winkel an die Außenwand grenzend, während sie in Variante 6 an der der Stallgasse zugewandten Seite des Liegebereichs aufgestellt wurde. Um eine Vergleichbarkeit mit einem Reitpferd zu schaffen, wurden alle Pferde in allen Haltungssystemen täglich für circa eine Stunde in einer Freilaufanlage bewegt. Die Stressbelastung wurde mittels der Messung der Herzfrequenzvariabilität (Parameter pNN50 und SD1) und der Bestimmung fäkaler Cortisolmetaboliten erfasst. Zusätzlich wurden Videoauswertungen hinsichtlich der Beobachtung von Verhaltensauffälligkeiten in den Haltungsvarianten 1 und 2 durchgeführt. Die durchschnittlich niedrigste Stressbelastung erfuhren die Pferde durch die Haltungsvarianten 4 (pNN50: 46,32 %, SD1:158,58 ms, Cortisolmetaboliten: 21,01nmol/kg Kot) und 6 (pNN50: 47,1 %, SD1: 144,62 ms, Cortisolmetaboliten: 21,01 nmol/kg Kot). Die
141 Auswertung der pNN50- und Cortisolmetabolitenwerte ergab die größte Stressbelastung der Pferde in den Varianten 1 (pNN50: 42,81 %, SD1: 134,52 ms, Cortisolmetaboliten: 28,56 nmol/kg Kot) und 3 (pNN50: 42,41 %, SD1: 135,36, Cortisolmetaboliten: 28,60 nmol/kg Kot). Die Auswertung der SD1-Werte zeigte zusätzlich noch eine hohe Stressbelastung der Pferde in der Variante 5 (pNN50: 44,83 %, SD1: 119,24 ms, Cortisolmetaboliten: 27,18 nmol/kg Kot). Die Haltungsvariante 2 (pNN50: 45,77 %, SD1: 144,25 ms, Cortisolmetaboliten: 27,59 nmol/kg Kot) beziehungsweise die Varianten 2 und 5 (bei der Betrachtung der pNN50- und der Cortisolmetabolitenwerte) verursachten im Durchschnitt eine mittlere Stressbelastung. Teilweise waren die Unterschiede jedoch zu gering um die Signifikanzgrenze zu überschreiten. Die Betrachtung der einzelnen Pferde und der Pferdegruppen ergab große interindividuelle Unterschiede und deutliche gruppenspezifische Gemeinsamkeiten. Die Position eines Tieres in der Rangordnung hatte in diesen Untersuchungen bei der Betrachtung der Mittelwerte keinen Einfluss auf die Stressbelastung in Abhängigkeit der Haltungsvariante. Vielmehr zeigten sich auch hier deutliche individuelle Unterschiede in der Stressanfälligkeit und den Vorlieben der einzelnen Pferde bezüglich der verschiedenen Haltungssysteme. Die Analyse der Videoaufzeichnungen ergab, dass mehrere Pferde Kreisbewegungen in der Einzelbox ohne Auslauf (Variante 1) zeigten, während in der Variante 2 (Paddockbox) kein Pferd durch Kreisbewegungen auffiel. Andere Verhaltensauffälligkeiten oder gar Verhaltensstörungen wurden nicht beobachtet. Bei der Auswertung der Aufenthaltshäufigkeit und der Aufenthaltesdauer in den 4 Boxenquadranten zeigten sich einige Pferde sehr aktiv, was ein Hinweis auf eventuelle Unruhe oder Nervosität sein kann, während andere Pferde im Vergleich zum Gruppendurchschnitt sehr ruhig wirkten, da sie sich in der Box kaum bewegten und über lange Zeitabschnitte in einem Quadranten standen. Obwohl die Gruppenhaltung für die Mehrzahl der Pferde eine geringere Stressbelastung bedeutete und auch hinsichtlich des Bewegungs- und Sozialverhaltens am artgerechtesten einzustufen ist, sollte für jedes Pferd individuell unter Berücksichtigung seines Alters, seiner Rasse, seines Nutzungsgrades, aber vor allem seines Charakters und seiner Erfahrungen im Sozialverhalten ein passendes großzügig bemessenes Haltungssystem ermittelt werden, um 142 die durch das Haltungssystem ausgeübte Stressbelastung zu minimieren und das Wohlbefinden der Pferde zu steigern. |
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Liberg, O., Chapron, G., Wabakken, P., Pedersen, H. C., Hobbs, N. T., & Sand, H. (2012). Shoot, shovel and shut up: cryptic poaching slows restoration of a large carnivore in Europe. Proc. R. Soc. Lond. B, 279(1730), 910–915.
Abstract: Poaching is a widespread and well-appreciated problem for the conservation of many threatened species. Because poaching is illegal, there is strong incentive for poachers to conceal their activities, and consequently, little data on the effects of poaching on population dynamics are available. Quantifying poaching mortality should be a required knowledge when developing conservation plans for endangered species but is hampered by methodological challenges. We show that rigorous estimates of the effects of poaching relative to other sources of mortality can be obtained with a hierarchical state-space model combined with multiple sources of data. Using the Scandinavian wolf (Canis lupus) population as an illustrative example, we show that poaching accounted for approximately half of total mortality and more than two-thirds of total poaching remained undetected by conventional methods, a source of mortality we term as 'cryptic poaching'. Our simulations suggest that without poaching during the past decade, the population would have been almost four times as large in 2009. Such a severe impact of poaching on population recovery may be widespread among large carnivores. We believe that conservation strategies for large carnivores considering only observed data may not be adequate and should be revised by including and quantifying cryptic poaching.
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Plumer, L., Talvi, T., Männil, P., & Saarma, U. (2018). Assessing the roles of wolves and dogs in livestock predation with suggestions for mitigating human-wildlife conflict and conservation of wolves. Conservat. Genet., 19(3), 665–672.
Abstract: Predation on livestock is a cause of serious and long-lasting conflict between farmers and wildlife, promoting negative public attitudes and endangering conservation of large carnivores. However, while large carnivores, especially the grey wolf (Canis lupus), are often blamed for killing sheep and other farm animals, free-ranging dogs may also act as predators. To develop appropriate measures for livestock protection, reliable methods for identifying predator species are critical. Identification of predators from visual examination of livestock wounds can be ambiguous and genetic analysis is strongly preferable for accurate species determination. To estimate the proportion of wolves and dogs implicated in sheep predation, we developed a sensitive genetic assay to distinguish between wolves and domestic dogs. A total of 183 predator saliva samples collected from killed sheep in Estonia were analysed. The assay identified the predator species in 143 cases (78%). Sheep were most often killed by wolves (81%); however, predation by dogs was substantial (15%). We compared the molecular results with field observations conducted by local environmental officials and recorded some disagreement, with the latter underestimating the role of dogs. As predator saliva samples collected from prey are often of poor quality, we suggest using mitochondrial DNA as a primary tool to maximise the number of successfully analysed samples. We also suggest adopting forensic DNA analysis more widely in livestock predation assessments as a legislative measure since misidentification that is biased against wolves can be counterproductive for conservation by enhancing conflict with society and leading to increased culling and poaching.
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Pimenta, V., Barroso, I., Boitani, L., & Beja, P. (2018). Risks a la carte: Modelling the occurrence and intensity of wolf predation on multiple livestock species. Biol. Conserva., 228, 331–342.
Abstract: Predation on livestock is a source of human-wildlife conflicts and can undermine the conservation of large carnivores. To design effective mitigation strategies, it is important to understand the determinants of predation across livestock species, which often differ in husbandry practices, vulnerability to predators and economic value. Moreover, attention should be given to both predation occurrence and intensity, because these can have different spatial patterns and predictors. We used spatial risk modelling to quantify factors affecting wolf predation on five livestock species in Portugal. Within the 1619 parishes encompassing the entire wolf range in the country, the national wolf compensation scheme recorded 17,670 predation events in 2009-2015, each involving one or more livestock species: sheep (31.7%), cattle (27.7%), goats (26.8%), horses (14.8%) and donkeys (3.2%). Models built with 2009-2013 data and validated with 2014-2015 data, showed a shared general pattern of predation probability on each species increasing with its own density and proximity to wolf packs. For some species there were positive relations with the density of other livestock species, and with habitat variables such as altitude, and land cover by shrubland and natural pastures. There was also a general pattern for predation intensity on each species increasing with its own density, while proximity to wolf packs had no significant effects. Predation intensity on goats, cattle and horses increased with the use of communal versus private pastures. Our results suggest that although predation may occur wherever wolves coexist with livestock species, high predation intensity is mainly restricted to particular areas where husbandry practices increase the vulnerability of animals, and this is where mitigation efforts should concentrate.
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Janczarek, I., Stachurska, A., Kedzierski, W., Wisniewska, A., Ryzak, M., & Koziol, A. (2020). The intensity of physiological and behavioral responses of horses to predator vocalizations. BMC Veterinary Research, 16(1), 431.
Abstract: Predatory attacks on horses can become a problem in some parts of the world, particularly when considering the recovering gray wolf populations. The issue studied was whether horses transformed by humans and placed in stable-pasture environments had retained their natural abilities to respond to predation risk. The objective of the study was to determine the changes in cardiac activity, cortisol concentrations, and behavior of horses in response to the vocalizations of two predators: the gray wolf (Canis lupus), which the horses of the breed studied had coevolved with but not been exposed to recently, and Arabian leopard (Panthera pardus nimr), from which the horses had been mostly isolated. In addition, we hypothesized that a higher proportion of Thoroughbred (TB) horse ancestry in the pedigree would result in higher emotional excitability in response to predator vocalizations. Nineteen horses were divided into groups of 75%, 50% and 25% TB ancestry. The auditory test conducted in a paddock comprised a 10-min prestimulus period, a 5-min stimulus period when one of the predators was heard, and a 10-min poststimulus period without any experimental stimuli.
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Rørvang, M. V., Christensen, J. W., Ladewig, J., & McLean, A. (2018). Social Learning in Horses--Fact or Fiction? Front. Vet. Sci., 5, 212.
Abstract: Prima facie, the acquisition of novel behaviors in animals through observation of conspecifics seems straightforward. There are, however, various mechanisms through which the behavior of animals can be altered from observing others. These mechanisms range from simple hard-wired contagious processes to genuine learning by observation, which differ fundamentally in cognitive complexity. They range from social facilitation and local enhancement to true social learning. The different learning mechanisms are the subject of this review, largely because research on learning by observation can be confounded by difficulties in interpretation owing to the looming possibility of associative learning infecting experimental results. While it is often assumed that horses are capable of acquiring new behavior through intra-species observation, research on social learning in horses includes a variety of studies some of which may overestimate the possession of higher mental abilities. Assuming such abilities in their absence can have welfare implications, e.g. isolating stereotypical horses on the assumption that these behaviors can be learned though observation by neighboring horses. This review summarizes the definitions and criteria for the various types of social transmission and social learning and reviews the current documentation for each type in horses with the aim of clarifying whether horses possess the ability to learn through true social learning. As social ungulates, horses evolved in open landscapes, exposed to predators and grazing most of the day. Being in close proximity to conspecifics may theoretically offer an opportunity to learn socially, however anti-predator vigilance and locating forage may not require the neural complexity of social learning. Given the significant energetic expense of brain tissue, it is likely that social facilitation and local enhancement may have been sufficient in the adaptation of equids to their niche. As a consequence, social learning abilities may be maladaptive in horses. Collectively, the review proposes a novel differentiation between social transmission (social facilitation, local and stimulus enhancement) and social learning (goal emulation, imitation). Horses are undoubtedly sensitive to intra-species transfer of information but this transfer does not appear to satisfy the criteria for social learning, and thus there is no solid evidence for true social learning in horses.
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Chapron, G., & Treves, A. (2016). Blood does not buy goodwill: allowing culling increases poaching of a large carnivore. Proc. R. Soc. Lond. B, 283(1830).
Abstract: Quantifying environmental crime and the effectiveness of policy interventions is difficult because perpetrators typically conceal evidence. To prevent illegal uses of natural resources, such as poaching endangered species, governments have advocated granting policy flexibility to local authorities by liberalizing culling or hunting of large carnivores. We present the first quantitative evaluation of the hypothesis that liberalizing culling will reduce poaching and improve population status of an endangered carnivore. We show that allowing wolf (Canis lupus) culling was substantially more likely to increase poaching than reduce it. Replicated, quasi-experimental changes in wolf policies in Wisconsin and Michigan, USA, revealed that a repeated policy signal to allow state culling triggered repeated slowdowns in wolf population growth, irrespective of the policy implementation measured as the number of wolves killed. The most likely explanation for these slowdowns was poaching and alternative explanations found no support. When the government kills a protected species, the perceived value of each individual of that species may decline; so liberalizing wolf culling may have sent a negative message about the value of wolves or acceptability of poaching. Our results suggest that granting management flexibility for endangered species to address illegal behaviour may instead promote such behaviour.
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Gardner, E. L., & Engel, D. R. (1971). Imitational and social facilitatory aspects of observational learning in the laboratory rat. Psychon. Sci., 25(1), 5–6.
Abstract: Rats acquired a food-motivated leverpressing response by “observational learning” or by trial-and-error learning under conditions of social facilitation or isolation. Both the observational learning and social facilitation Ss learned faster than did the isolated trial-and-error Ss. There was no difference in speed of learning between the observational learning and social facilitation groups. It is suggested that some previous studies purporting to demonstrate observational learning may have demonstrated socially facilitated trial-and-error learning instead.
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Rhodin, M., Johnston, C., Holm, K. R., Wennerstrand, J., & Drevemo, S. (2005). The influence of head and neck position on kinematics of the back in riding horses at the walk and trot. Equine Vet J, 37(1), 7–11.
Abstract: REASONS FOR PERFORMING STUDY: A common opinion among riders and in the literature is that the positioning of the head and neck influences the back of the horse, but this has not yet been measured objectively. OBJECTIVES: To evaluate the effect of head and neck position on the kinematics of the back in riding horses. METHODS: Eight Warmblood riding horses in regular work were studied on a treadmill at walk and trot with the head and neck in 3 different predetermined positions achieved by side reins attached to the bit and to an anticast roller. The 3-dimensional movement of the thoracolumbar spine was measured from the position of skin-fixed markers recorded by infrared videocameras. RESULTS: Head and neck position influenced the movements of the back, especially at the walk. When the head was fixed in a high position at the walk, the flexion-extension movement and lateral bending of the lumbar back, as well as the axial rotation, were significantly reduced when compared to movements with the head free or in a low position. At walk, head and neck position also significantly influenced stride length, which was shortest with the head in a high position. At trot, the stride length was independent of head position. CONCLUSIONS: Restricting and restraining the position and movement of the head and neck alters the movement of the back and stride characteristics. With the head and neck in a high position stride length and flexion and extension of the caudal back were significantly reduced. POTENTIAL RELEVANCE: Use of side reins in training and rehabilitation programmes should be used with an understanding of the possible effects on the horse's back.
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