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Author Arlettaz, R.; Patthey, P.; Baltic, M.; Leu, T.; Schaub, M.; Palme, R.; Jenni-Eiermann, S.
Title Spreading free-riding snow sports represent a novel serious threat for wildlife Type Journal Article
Year 2007 Publication Proceedings. Biological Sciences / The Royal Society Abbreviated Journal Proc Biol Sci
Volume (down) 274 Issue 1614 Pages 1219-1224
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Abstract Stress generated by humans on wildlife by continuous development of outdoor recreational activities is of increasing concern for biodiversity conservation. Human disturbance often adds to other negative impact factors affecting the dynamics of vulnerable populations. It is not known to which extent the rapidly spreading free-riding snow sports actually elicit detrimental stress (allostatic overload) upon wildlife, nor what the potential associated fitness and survival costs are. Using a non-invasive technique, we evaluated the physiological stress response induced by free-riding snow sports on a declining bird species of Alpine ecosystems. The results of a field experiment in which radiomonitored black grouse (Tetrao tetrix) were actively flushed from their snow burrows once a day during four consecutive days showed an increase in the concentration of faecal stress hormone (corticosterone) metabolites after disturbance. A large-scale comparative analysis across the southwestern Swiss Alps indicated that birds had higher levels of these metabolites in human-disturbed versus undisturbed habitats. Disturbance by snow sport free-riders appears to elevate stress, which potentially represents a new serious threat for wildlife. The fitness and survival costs of allostatic adjustments have yet to be estimated.
Address Zoological Institute, Division of Conservation Biology, University of Bern, Baltzerstrasse 6, 3012 Bern, Switzerland. raphael.arlettaz@nat.unibe.ch
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ISSN 0962-8452 ISBN Medium
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Notes PMID:17341459 Approved no
Call Number Equine Behaviour @ team @ Serial 4075
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Author King, S.R.B.; Gurnell, J.
Title Scent-marking behaviour by stallions: an assessment of function in a reintroduced population of Przewalski horses (Equus ferus przewalskii) Type Journal Article
Year 2007 Publication Journal of Zoology Abbreviated Journal J Zool
Volume (down) 272 Issue 1 Pages 30-36
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Abstract Abstract Scent marking is a common form of intraspecific communication in mammal species, and using faeces or urine is a cost-effective way of signalling competitive ability and resource holding power. Marking is ritually performed by male equids, and here we assess the function of male scent-marking behaviour in a recently introduced population of Przewalski horses Equus ferus przewalskii in Mongolia. Two forms of scent marking were observed: defecation on stud piles formed from repeated dunging in the same place, and overmarking of faeces and urine of mares. Stud piles were marked with dung by the harem holder and sniffed before and after dung was deposited. They were not found specifically at the periphery of harem ranges but occurred for the most part along routes used by the horses, and were more common in the core parts of harem ranges or where harem ranges overlapped. Thus, rather than being used to defend range boundaries, stud piles were placed predominantly where they would be encountered by male intruders. Mare excreta were covered with urine by the stallion, but were only sniffed before they were marked, not after. These marks appear to advertise to the mare and other, intruding stallions that the harem holder was the mare's consort and that the interloper should not risk trying to steal the mare or sneak a mating. Thus, the two forms of marking by harem holders appear to combine as first and second lines of defence of paternity rights in male intrasexual competition.
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Call Number Equine Behaviour @ team @ King2007 Serial 2315
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Author Bobbert, M.F.; Alvarez, C.B.G.; van Weeren, P.R.; Roepstorff, L.; Weishaupt, M.A.
Title Validation of vertical ground reaction forces on individual limbs calculated from kinematics of horse locomotion Type Journal Article
Year 2007 Publication The Journal of Experimental Biology Abbreviated Journal J Exp Biol
Volume (down) 210 Issue Pt 11 Pages 1885-1896
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Abstract The purpose of this study was to determine whether individual limb forces could be calculated accurately from kinematics of trotting and walking horses. We collected kinematic data and measured vertical ground reaction forces on the individual limbs of seven Warmblood dressage horses, trotting at 3.4 m s(-1) and walking at 1.6 m s(-1) on a treadmill. First, using a segmental model, we calculated from kinematics the total ground reaction force vector and its moment arm relative to each of the hoofs. Second, for phases in which the body was supported by only two limbs, we calculated the individual reaction forces on these limbs. Third, we assumed that the distal limbs operated as linear springs, and determined their force-length relationships using calculated individual limb forces at trot. Finally, we calculated individual limb force-time histories from distal limb lengths. A good correspondence was obtained between calculated and measured individual limb forces. At trot, the average peak vertical reaction force on the forelimb was calculated to be 11.5+/-0.9 N kg(-1) and measured to be 11.7+/-0.9 N kg(-1), and for the hindlimb these values were 9.8+/-0.7 N kg(-1) and 10.0+/-0.6 N kg(-1), respectively. At walk, the average peak vertical reaction force on the forelimb was calculated to be 6.9+/-0.5 N kg(-1) and measured to be 7.1+/-0.3 N kg(-1), and for the hindlimb these values were 4.8+/-0.5 N kg(-1) and 4.7+/-0.3 N kg(-1), respectively. It was concluded that the proposed method of calculating individual limb reaction forces is sufficiently accurate to detect changes in loading reported in the literature for mild to moderate lameness at trot.
Address Institute for Fundamental and Clinical Human Movement Sciences, Vrije Universiteit, van der Boechorstraat 9, NL-1081 BT Amsterdam, The Netherlands
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ISSN 0022-0949 ISBN Medium
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Notes PMID:17515415 Approved no
Call Number Equine Behaviour @ team @ Serial 3700
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Author Roth, L.S.V.; Balkenius, A.; Kelber, A.
Title Colour perception in a dichromat Type Journal Article
Year 2007 Publication Journal of Experimental Biology Abbreviated Journal
Volume (down) 210 Issue 16 Pages 2795-2800
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Abstract Most mammals have dichromatic colour vision based on two different types of cones: a short-wavelength-sensitive cone and a long-wavelength-sensitive cone. Comparing the signal from two cone types gives rise to a one-dimensional chromatic space when brightness is excluded. The so-called `neutral point' refers to the wavelength that the animal cannot distinguish from achromatic light such as white or grey because it stimulates both cone types equally. The question is: how do dichromats perceive their chromatic space? Do they experience a continuous scale of colours or does the neutral point divide their chromatic space into two colour categories, i.e. into colours of either short or long wavelengths?We trained horses to different colour combinations in a two-choice behavioural experiment and tested their responses to the training and test colours. The horses chose colours according to their similarity/relationship to rewarded and unrewarded training colours. There was no evidence for a categorical boundary at the neutral point or elsewhere.This study suggests that dichromats perceive their chromatic space as a continuous scale of colours, treating the colour at the neutral point as any other colour they can distinguish.
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Call Number Equine Behaviour @ team @ Serial 5711
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Author Dugnol, B.; Fernández, C.; Galiano, G.; Velasco, J.
Title Implementation of a diffusive differential reassignment method for signal enhancement: An application to wolf population counting Type Journal Article
Year 2007 Publication Appl Math Comput Abbreviated Journal
Volume (down) 193 Issue Pages
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Call Number Equine Behaviour @ team @ Dugnol2007 Serial 6465
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Author Dugnol, B.; Fernández, C.; Galiano, G.
Title Wolf population counting by spectrogram image processing Type Journal Article
Year 2007 Publication Appl Math Comput Abbreviated Journal
Volume (down) 186 Issue Pages
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Call Number Equine Behaviour @ team @ Dugnol2007 Serial 6464
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Author Versace, E.; Morgante, M.; Pulina, G.; Vallortigara, G.
Title Behavioural lateralization in sheep (Ovis aries) Type Journal Article
Year 2007 Publication Behavioural Brain Research Abbreviated Journal Behav. Brain. Res.
Volume (down) 184 Issue 1 Pages 72-80
Keywords Lateralization; Laterality; Brain asymmetry; Hemisphere; Sheep; Lamb; Strength of lateralization
Abstract This study investigates behavioural lateralization in sheep and lambs of different ages. A flock was tested in a task in which the animals were facing an obstacle and should avoid it on either the right or left side to rejoin flock-mates (adult sheep) or their mothers (lambs). A bias for avoiding the obstacle on the right side was observed, with lambs apparently being more lateralized than sheep. This right bias was tentatively associated with the left-hemifield laterality in familiar faces recognition which has been documented in this species. Differences between adult sheep and lambs were likely to be due to differences in social reinstatement motivation elicited by different stimuli (flock-mates or mothers) at different ages. Preferential use of the forelegs to step on a wood-board and direction of jaw movement during rumination was also tested in adult animals. No population bias nor individual-level lateralization was observed for use of the forelegs. At the same time, however, there was a large number of animals showing individual-level lateralization for the direction of jaw movement during rumination even though there was no population bias. These findings highlight that within the same species individual- and population-level lateralization can be observed in different tasks. Moreover, the results fit the general hypothesis that population-level asymmetries are more likely to occur in tasks that require social coordination among behaviourally asymmetric individuals.
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ISSN 0166-4328 ISBN Medium
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Notes Approved no
Call Number Equine Behaviour @ team @ Serial 6701
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Author Bannasch, D.; Rinaldo, C.; Millon, L.; Latson, K.; Spangler, T.; Hubberty, S.; Galuppo, L.; Lowenstine, L.
Title SRY negative 64,XX intersex phenotype in an American saddlebred horse Type Journal Article
Year 2007 Publication Veterinary Journal (London, England : 1997) Abbreviated Journal Vet J
Volume (down) 173 Issue 2 Pages 437-439
Keywords Animals; Female; Genitalia/abnormalities; Hermaphroditism/*veterinary; Horse Diseases/*diagnosis/genetics; Horses/*genetics/*physiology; Karyotyping; Phenotype; Sex Differentiation; Sex Differentiation Disorders/diagnosis/veterinary; Sex-Determining Region Y Protein/genetics/*metabolism
Abstract A female American saddlebred horse was presented for surgical correction of a possible pseudohermaphrodite condition. The horse had abnormal external genitalia and exhibited stallion-like behaviour. No evidence of uterine or ovarian tissue was identified on laparoscopic examination, but hypoplastic testicular-like tissue was removed, although this was found to contain no spermatogonia upon histopathological examination. A karyotype was performed and showed the normal chromosomal complement for a female horse (64,XX). Polymerase chain reaction to detect the SRY gene was negative in peripheral blood as well as the testicular-like tissue. This case represents the first report of an SRY negative XX-male sex reversal intersex phenotype, which is a potentially inherited condition, in an American saddlebred horse.
Address Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA 95616, USA. dlbannasch@ucdavis.edu
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ISSN 1090-0233 ISBN Medium
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Notes PMID:16386440 Approved no
Call Number Serial 1882
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Author Meschan, E.M.; Peham, C.; Schobesberger, H.; Licka, T.F.
Title The influence of the width of the saddle tree on the forces and the pressure distribution under the saddle Type Journal Article
Year 2007 Publication The Veterinary Journal Abbreviated Journal
Volume (down) 173 Issue 3 Pages 578-584
Keywords Saddle fit; Kinematics; Kinetics; Pressure; Saddletree
Abstract As there is no statistical evidence that saddle fit influences the load exerted on a horse's back this study was performed to assess the hypothesis that the width of the tree significantly alters the pressure distribution on the back beneath the saddle. Nineteen sound horses were ridden at walk and trot on a treadmill with three saddles differing only in tree width. Kinetic data were recorded by a sensor mat. A minimum of 14 motion cycles were used in each trial. The saddles were classified into four groups depending on fit. For each horse, the saddle with the lowest overall force (LOF) was determined. Saddles were classified as “too-narrow” if they were one size (2 cm) narrower than the LOF saddle, and “too-wide” if they were one size (2 cm) wider than the LOF saddle. Saddles two sizes wider than LOF saddles were classified as “very-wide”. In the group of narrow saddles, the pressure in the caudal third (walk 0.63 N/cm2 +/- 0.10; trot 1.08 N/cm2 +/- 0.26) was significantly higher compared to the LOF saddles (walk 0.50 N/cm2 +/- 0.09; trot 0.86 N/cm2 +/- 0.28). In the middle transversal third, the pressure of the wide saddles (walk 0.73 N/cm2 +/- 0.06; trot 1.52 N/cm2 +/- 0.19) and very-wide saddles (walk 0.77 N/cm2 +/- 0.06; trot 1.57 N/cm2 +/- 0.19) was significantly higher compared to LOF saddles (walk 0.65 N/cm2 +/- 0.10/ 0.63 N/cm2 +/- 0.11; trot 1.33 N/cm2 +/- 0.22/1.27 N/cm2 +/- 0.20). This study demonstrates that the load under poorly fitting saddles is distributed over a smaller area than under properly fitting saddles, leading to potentially harmful pressures peaks.
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Call Number Admin @ knut @ Serial 4349
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Author Harris, P.A.
Title How should we feed horses – and how many times a day? Type Journal Article
Year 2007 Publication The Veterinary Journal Abbreviated Journal
Volume (down) 173 Issue 2 Pages 252-253
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Call Number Admin @ knut @ Serial 4351
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