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Linklater, W. L., Cameron, E. Z., Stafford, K. J., & Minot, E. O. Estimating Kaimanawa feral horse population size and growth. In SCIENCE & RESEARCH INTERNAL REPORT 185.
Abstract: Animal flight behaviour in response to aircraft could have a profound influence
on the accuracy and precision of aerial estimates of population size but is rarely investigated. Using independent observers on the ground and in the air we recorded the presence and behaviour of 17 groups, including 136 individually marked horses, during a helicopter count in New Zealand’s Kaimanawa Mountains. We also compared the helicopter count with ground-based estimates using mark-resight and line-transect methods in areas ranging from 20.5 to 176 km2. Helicopter counts were from 16% smaller to 54% larger than ground-based estimates. The helicopter induced a flight response in all horse groups monitored. During flight, horse groups traveled from 0.1 up to 2.75 km before leaving the ground observer’s view and temporarily changed in size and composition. A tenth of the horses were not counted and a quarter counted twice. A further 23 (17%) may have been counted twice but only two of the three observers’ records concurred. Thus, the helicopter count over-estimated the marked sub-population by at least 15% and possibly by up to 32%. The net over-estimate of the marked sub-population corresponded to the 17% and 13% difference between helicopter counts and ground-based estimates in the central study area and for the largest area sampled, respectively. Feral horse flight behaviour should be considered when designing methods for population monitoring using aircraft. We identify the characteristics of the helicopter count that motivated horse flight behaviour. We compared our own recent estimate of population growth from measures of fecundity and mortality (λ = 1.096 with an earlier-published one (λ = 1.182, where r = 0.167) that had been derived by interpolating between the available history of single counts. Our model of population growth, standardised aerial counts, and historical estimates of annual reproduction suggest that the historical sequence of counts since 1979 probably over-estimated growth because count techniques improved and greater effort was expended in successive counts. We used line-transect, markresight and dung density sampling methods for population monitoring and discuss their advantages and limitations over helicopter counts. |
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Legare, C. H., & Nielsen, M. (). Imitation and Innovation: The Dual Engines of Cultural Learning. Trends in Cognitive Sciences, 19(11), 688–699.
Abstract: Imitation and innovation work in tandem to support cultural learning in children and facilitate our capacity for cumulative culture. Here we propose an integrated theoretical account of how the unique demands of acquiring instrumental skills and cultural conventions provide insight into when children imitate, when they innovate, and to what degree. For instrumental learning, with an increase in experience, high fidelity imitation decreases and innovation increases. By contrast, for conventional learning, imitative fidelity stays high, regardless of experience, and innovation stays low. We synthesize cutting edge research on the development of imitative flexibility and innovation to provide insight into the social learning mechanisms underpinning the uniquely human mind.
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Álvarez, I., Royo, L. J., Pérez-Pardal, L., Fernández, I., Lorenzo, L., & Goyache, F. (). Assessing diversity losses due to selection for coat colour in the endangered bay-Asturcón pony using microsatellites. Livest Sci, In Press, Corrected Proof.
Abstract: The bay-Asturcón pony (A21) population recovery started recently. A total of 297 samples (180 from founder individuals) belonging to the A21 population were genotyped for: a) a set of 15 microsatellites; and b) the presence of the two recessive chestnut alleles reported in the literature (e and ea) on the MC1r gene (locus Extension) and the deletion on the ASIP gene (locus Agouti) associated with recessive black coat in horses. The extent to which the genetic variability of the A21 population could be affected by selection strategies aimed at decreasing the frequency of the chestnut allele was quantified in terms of gene diversity and allelic richness. The possible genetic impact of a controlled introgression of A21 offspring into the black-coated Asturcón (A20) population was also assessed using 261 available A20 genotypes. The wild alleles for the Extension and Agouti loci (E and A, respectively) were the most frequent (77.8% and 59.4%) in the A21 population. Both the e and ea recessive chestnut alleles were identified with frequencies of 21.2% and 1.0%. As expected, the contribution to overall diversity of the founder subpopulation was always higher than that of the A21 offspring subpopulation. Total contribution of the offspring subpopulation to overall allelic richness was negative (- 1.84%), showing that all their alleles were present in the founder subpopulation. Although favourable, the chestnut carrier individuals had poor contributions to overall gene diversity and tended to have negative contributions to allelic richness. The elimination of the chestnut carrier A21 individuals would not affect genetic variability to a significant extent. Therefore, efforts for preserving the genetic variability in the A21 population could focus on a careful planning of matings between individuals free of the recessive chestnut alleles. The expected influence of a controlled introgression of A21 offspring on the genetic variability of the A20 population was always favourable. The gene diversity of the introgressed population was higher than that of the original A20 population for both gene diversity (GDT = -1.2% ± 0.04%) and, particularly, allelic richness (CT = 4.9% ± 0.27%). Very limited gene flow may increase the number of alleles of the A20 population but also would yield a balance of the allelic frequencies at a population level. Therefore, a common breeding policy for the two Asturcón pony populations may ensure the viability of this prominent genetic resource.
Keywords: Conservation; MC1r; Asip; Gene diversity; Allelic richness
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Górecka-Bruzda, A., Chruszczewski, M. H., Jezierski, T., & Murphy, J. (). Behaviour-related traits of Polish sport horse stallions participating in 100-day performance tests. Livest Sci, In Press, Corrected Proof.
Abstract: Sport horse studbooks frequently use performance tests to identify, evaluate and approve stallions for future breeding programmes. The aim of this study was to analyse behaviour-related traits of Polish Warmblood stallions participating in studbook 100-day performance tests. Both relatedness and differences of traits and their contribution to overall variability were analysed. Three-year-old stallions (n = 374) participated in 100-day performance test programmes at two Polish training stations from 2004 to 2008. Traits including character, temperament and trainability (trainer rated), free-jumping, jumping under the rider, walk, trot and canter (independently rated by both trainer and the selection jury) and jumping ability, dressage-ability and rideability (rated by the independent test rider) were subjected to Factor Analysis (FA) with varimax rotation. The FA produced three factors [Cooperation (Cp), Jumping Potential (JP) and Dressage Potential (DP)] with eigenvalues > 1, which accounted for 64.6% of the total variance of the traits examined. After rotation, the factors represented Cp: 23.2.0%, JP: 21.5% and DP: 19.8% of variance respectively. The traits of character, temperament, trainability, jumping under the rider, rideability, dressage and jumping abilities had high loadings on the second factor (Cp) and thereafter, the assessment of all behaviour-related traits contributed to the general evaluation with approximately one-fifth of total variability. The findings may indicate that successful sport careers for any horse may be much more closely associated with willingness to cooperate with the rider and riding and handling behaviour, than to the horse's actual physical performance potential. It would appear that only so-called sport-suitable performance of the horse is being selected for in performance tests (during jumping and dressage suitability testing). This approach may be short-sighted and inadequate with serious implications for horse under-performance in leisure activities notwithstanding general horse welfare within the disciplines of equitation.
Keywords: Horse; 100-day performance tests; Behaviour; Temperament; Factor Analysis
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Søndergaard, E., Jensen, M. B., & Nicol, C. J. (). Motivation for social contact in horses measured by operant conditioning. Appl. Anim. Behav. Sci., In Press, Corrected Proof.
Abstract: Although horses are social animals they are often housed individually with limited social contact to other horses and this may compromise their welfare. The present study included eight young female horses and investigated the strength of motivation for access to full social contact, head contact and muzzle contact, respectively, to a familiar companion horse. Horses were housed individually next to their companion horse and separations between pens prevented physical contact. During daily test sessions horses were brought to a test area where they could access an arena allowing social contact. Arena access during 3 min was given after completion of a predetermined number of responses on a panel. Fixed ratios (FR) of 8, 16, 24, 32 and 40 responses per arena access were applied in a random order, one per daily test session, within each test week (Monday to Friday), and the number of rewards per daily test session was recorded. All horses could access all three types of social contact in a cross-over design, and an empty arena was used as control. Motivational strength was assessed using elasticity of demand functions, which were estimated based on the number of rewards earned and FR. Elasticities of demand for the three types of social contact were low (-0.20), and not significantly different, although increasing FR still resulted in a decrease in rewards obtained for all three types of social contact (P < 0.001). Across FR-levels horses earned more rewards for social contact than for an empty arena, as shown by much higher intercept values (2.51 vs. 0.99; P < 0.001). However, the elasticity of demand for infrequent access to an empty arena (-0.08) was lower than for social contact (P < 0.01) and not significantly different from zero (P = 0.07). Horses performed more social behaviour the lesser the restriction on social contact (full > head > muzzle). However, the finding that horses showed a similar and high motivation for all three types of social contact suggests that they are valued equally highly in a situation where the alternative is no social contact.
Keywords: Horse; Housing; Social behaviour; Operant conditioning; Motivation
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Górecka-Bruzda, A., Jastrzebska, E., Sosnowska, Z., Jaworski, Z., Jezierski, T., & Chruszczewski, M. H. (). Reactivity to humans and fearfulness tests: Field validation in Polish Cold Blood Horses. Appl. Anim. Behav. Sci., In Press, Corrected Proof.
Abstract: The aim of the present paper was to examine in field conditions the feasibility of the experimentally developed behavioural tests for assessment of two temperamental traits of cold blood horses: fearfulness and reactivity to humans. The predictive, convergent and discriminant validity of the tests was evaluated. Fifty-three Polish Cold Blood Horses (CBHs) were tested with the battery of behavioural tests involving passive and active contact with humans, handling, startling, novel object and surface tests. The behaviour of horses in real, on-farm conditions was evaluated with the caretaker's questionnaire (CQ). The tests demonstrated that a non-startling object and unforced human manipulations were willingly accepted by horses. In contrast, the horses were more reluctant to interact spontaneously with humans and showed longer persistence of a withdrawal reaction when presented with a startling stimulus or when restrained. CQ confirmed the common opinion of calmness, patience and good manageability of the CBHs. The results of behavioural tests were correlated with the scores derived from factor analysis of the CQ. Moreover, the majority of tests measures were correlated within reactivity to humans (median rs = 0.56) and fear tests (median rs = 0.41). Thus, predictive and convergent validity of the employed tests has been confirmed. However, reactivity to humans and fear measures were also correlated (median rs = 0.36), therefore discriminant validity of the tests used has been not confirmed. Therefore, we suggest that the parameters of tests designed to measure two separate traits: reactivity to humans and fearfulness, measured in fact avoidance of potential harm and withdrawal behaviour. Although selection for the work-appropriate behaviour is almost nonexistent nowadays, we conclude that Polish Cold Blood Horses are still predisposed for disciplines of equitation and driving, which demand an easy to handle horse. Nonetheless, we recommend behavioural testing of horses when approving for breeding. For this purpose, we can confirm usefulness of the experimentally developed tests in field assessment of general behavioural reactivity of horses.
Keywords: Cold blood horse; Temperament; Reactivity; Behavioural tests; Questionnaire; Validity
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Birke, L., Hockenhull, J., Creighton, E., Pinno, L., Mee, J., & Mills, D. (). Horses' responses to variation in human approach. Appl. Anim. Behav. Sci., In Press, Corrected Proof.
Abstract: The behaviour of humans around horses is thought to have a substantial impact on how people are perceived in subsequent interactions and many horse trainers give detailed advice on how handlers should behave when initially approaching a loose horse. Here we report on three studies designed to explore the effect of different human approach styles on the behaviour of naïve and experienced horses. In the first study, the change in flight distance (distance at which horses started to avoid an approaching human) of twelve semi-feral Dartmoor ponies, undergoing training to allow handling, was assessed. Over the 10 handling sessions median flight distance decreased significantly (p < 0.001) from 2.38 m to 0.00 m and there was a significant positive shift in the ponies' behaviour following the appearance of the researcher (p = 0.002). In a second study the effect of a direct (vigorous, swinging a lead rope and with eye contact) versus indirect (relaxed, no rope swinging and without eye contact) approach style was assessed on six adult experienced riding horses. The mean flight distance during a direct approach style (6.87 m) was significantly greater than that which occurred during an indirect approach style (2.32 m). Direction of approach was not found to significantly affect flight distance. In a third study, the effect of the rope was removed and a similar method to the second study applied to a group of naïve, feral ponies. The effect of different components of approach style, speed of approach, handler body posture and direction of gaze, which might contribute to observed differences in behavioural responses, were then examined systematically in this population. This revealed no significant difference in mean flight distance between the two approach styles (2.28 m indirect versus 2.37 m direct approach), but ponies were significantly more likely to move off in trot (p = 0.025) and to travel further (p = 0.001) when a direct approach was used. Speed of approach was the most salient factor, with a fast approach increasing both the tendency to move off in trot (p < 0.001) and distance travelled (p < 0.001). Body posture (relaxed or tense) had no effect, while flight distance was significantly greater when the person was looking away (p = 0.045). These results suggest horses may have an important egocentric spatial barrier, which perhaps relates to personal space and triggering of the flight response. Contrary to popular belief, body posture did not appear to be very important in the contexts examined unless accompanied by extraneous aids, while the speed of approach is particularly significant. These results are of important practical relevance in reducing the risk of injury, and the effective management of horses with minimal stress.
Keywords: Horse; Flight response; Human approach; Body posture; Approach speed; Natural horsemanship
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Hartmann, E., Søndergaard, E., & Keeling, L. J. Keeping horses in groups: A review. Appl. Anim. Behav. Sci., .
Abstract: Although husbandry conditions for horses have improved over the last decades, many horses are still kept singly with limited or no physical contact to other horses. This is surprising, given the fact that keeping horses in groups is recognised best to fulfil their physical and behavioural needs, especially their need for social contact with conspecifics, as well as to have a beneficial effect on horse–human interactions during training. Group housing of farm animals is widely applied in practice. As a consequence, scientists have investigated numerous aspects of group housing to help further improve animal welfare and human–animal interactions under these conditions. However, compared to this literature available in farm animals, and the plentiful studies conducted of feral horse populations, there is much less done when it comes to the management of horses kept in groups in the domestic environment. In particular, limited scientific information is available into the effect of group size and group composition on behaviour and methods of introducing new horses into established groups, even though problems related to social integration are repeatedly taken as arguments against keeping horses in groups. This review, therefore, aims to provide an overview of the current scientific knowledge regarding keeping horses in groups. Furthermore, it aims to give insight into whether or not some of the concerns related to keeping horses in groups are justified and to review scientifically based solutions that could be useful in practice to improve horse welfare and human safety.
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Moeller, B. A., McCall, C. A., Silverman, S. J., & McElhenney, W. H. (). Estimation of Saliva Production in Crib-Biting and Normal Horses. Journal of Equine Veterinary Science, 28(2), 85–90.
Abstract: Increasing saliva flow to buffer the stomach has been hypothesized as a basis for crib-biting in horses. Saliva amounts in seven cribbing and seven noncribbing (control) horses were compared either pre- and post-cribbing or at pre- and post-5-minute intervals for controls. A pre-weighed cellulose sponge was used to collect saliva at the exit of the submandibular gland for 30 seconds, then reweighed. Data were analyzed as repeated measures. Mean saliva weight overall was similar between cribbing and control horses (1.2 and 1.5 g, respectively, SE = 0.2). However, mean saliva weight for pre- and post-samples (1.5 and 1.2 g, respectively, SE = 0.06) for all horses was significantly lower (P < .05) in the post-sample, indicating a drying effect of the sponge. Because of a strong tendency (P < .06) for a treatment-by-sampling time interaction, data were analyzed by sampling time and cribbing status. Mean saliva weights in the pre-sample were 0.43 g higher (P < .03) in control than cribbing horses. Control horses showed a 0.38 g decrease (P < .01) in saliva weight between pre- and post-samples, which was not evident in cribbing horses. To determine whether cribbing offset the saliva decrease seen in control horses, nine cribbing horses were sampled as before but prevented from cribbing between samples. A similar reduction (0.39 g, P < .01) in saliva weights between samples with cribbing allowed versus cribbing prevented was seen in these horses as was seen in control horses in the initial study. Because cribbing does produce saliva, gastrointestinal irritation could be a motivating cause for cribbing.
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Keeling, L. J., Bøe, K. E., Christensen, J. W., Hyyppä, S., Jansson, H., Jørgensen, G. H. M., et al. Injury incidence, reactivity and ease of handling of horses kept in groups: a matched case control study in four Nordic countries. Appl Anim Behav Sci, .
Abstract: Abstract There is increasing interest in keeping horses in groups, but progress is hampered by a lack of knowledge about which horses can and should be kept together. Therefore, our objective was to investigate the effect of group composition on the occurrence of injuries among horses, the ease of removing horses from groups and horses’ reactivity to a fearful stimulus. Using a matched case control design, 61 groups of horses were studied in Denmark, Norway, Finland and Sweden. They were allocated into groups of similar or different age and sex or where membership changed regularly or remained stable. Injuries were recorded before mixing the horses into treatment groups, the day after mixing and four weeks later. Reactivity of horses to a moving novel object and the behaviour of a horse being removed from its group and the reactions of other group members towards this horse and the handler were evaluated. It was hypothesized that a more socially variable group composition has beneficial effects on behaviour, ease of handling and reducing reactivity whereas frequent changes in group composition has negative consequences, resulting in more injuries. We found that differences in treatment effects were mainly related to breed, rather than group composition. Icelandic horses reacted less to the movement of the novel object (P = 0.007) and approached it more afterwards (P = 0.04). They also had fewer new injuries than warmbloods following mixing (P < 0.001) and fewer than all other groups 4 weeks later (P < 0.01). Most new injuries after mixing were minor and recorded on the horse’s head, chest, hind legs and rump. In conclusion, variations in sex and age composition of the group had little effect on injury level, reactivity and ease of handling compared to the general effect of breed. Concerns about the risk of severe injuries associated with keeping horses in groups are probably overestimated. Thus, we propose that horses can be successfully kept in groups of different sex and age composition.
Keywords: horse; behaviour; reactivity; injury; welfare; management
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