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Ward, A. J. W., Sumpter, D. J. T., Couzin, I. D., Hart, P. J. B., & Krause, J. (2008). Quorum decision-making facilitates information transfer in fish shoals. Proc. Natl. Acad. Sci. U.S.A., 105(19), 6948–6953.
Abstract: Despite the growing interest in collective phenomena such as “swarm intelligence” and “wisdom of the crowds,” little is known about the mechanisms underlying decision-making in vertebrate animal groups. How do animals use the behavior of others to make more accurate decisions, especially when it is not possible to identify which individuals possess pertinent information? One plausible answer is that individuals respond only when they see a threshold number of individuals perform a particular behavior. Here, we investigate the role of such “quorum responses” in the movement decisions of fish (three-spine stickleback, Gasterosteus aculeatus). We show that a quorum response to conspecifics can explain how sticklebacks make collective movement decisions, both in the absence and presence of a potential predation risk. Importantly our experimental work shows that a quorum response can reduce the likelihood of amplification of nonadaptive following behavior. Whereas the traveling direction of solitary fish was strongly influenced by a single replica conspecific, the replica was largely ignored by larger groups of four or eight sticklebacks under risk, and the addition of a second replica was required to exert influence on the movement decisions of such groups. Model simulations further predict that quorum responses by fish improve the accuracy and speed of their decision-making over that of independent decision-makers or those using a weak linear response. This study shows that effective and accurate information transfer in groups may be gained only through nonlinear responses of group members to each other, thus highlighting the importance of quorum decision-making.
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Hausberger, M., Roche, H., Henry, S., & Visser, E. K. (2008). A review of the human-horse relationship. Appl. Anim. Behav. Sci., 109(1), 1–24.
Abstract: Despite a long history of human-horse relationship, horse-related incidents and accidents do occur amongst professional and non professional horse handlers. Recent studies show that their occurrence depend more on the frequency and amount of interactions with horses than on the level of competency, suggesting a strong need for specific research and training of individuals working with horses. In the present study, we review the current scientific knowledge on human-horse relationships. We distinguish here short occasional interactions with familiar or unfamiliar horses (e.g. veterinary inspection) and long-term bonds (e.g. horse-owner). An important aspect of the horse-human relationship is to try and improve the development and maintenance of a strong positive relationship. Studies show that deficits in the management conditions (housing, feeding, possibilities for social contact, and training methods) may lead to relational problems between horses and humans. Different methods have been used to assess and improve the human-horse relation, especially at the young age. They reveal that the time and type of contact all play a role, while recent studies suggest that the use of familiarized social models might be a great help through social facilitation. We argue that an important theoretical framework could be Hinde's [Hinde, R., 1979. Towards Understanding Relationships. Academic Press, Londres] definition of a relationship as an emerging bond from a series of interactions: partners have expectations on the next interaction on the basis of the previous ones. Understanding that a relationship is built up on the basis of a succession of interactions is an important step as it suggests that attention is being paid to the “positive” or “negative” valence of each interaction as a step for the next one. A better knowledge of learning rules is certainly necessary in this context not only to train the horse but also to counterbalance the unavoidable negative inputs that exist in routine procedures and reduce their impact on the relationship. It appears clearly that research is needed in order to assess how to better and safely approach the horse (e.g. research in position, posture, gaze, etc.), what type of approaches and timing may help in developing a positive bond, what influence human management and care have on the relationship, and how this can be adapted to have a positive influence on the relationship. Also the interaction between rider and horse, the search for the optimal match between two individuals, is an aspect of the horse-human relationship that requires attention in order to decrease the number of horse-riding accidents and reduced states of welfare. On the other hand, adequate knowledge is readily available that may improve the present situation rapidly. Developing awareness and attention to behavioural cues given by horses would certainly help decreasing accidents among professionals when interacting. Scientists therefore should play a major role in transmitting not only elements of the current knowledge of the ethology of the horse but also by helping developing observational skills.
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Baragli, P., Cozzi, A., Rugani, R., Sighieria, C., & Regolin, L. (2008). Delayed search for non-social goals by Equids (Equus caballus and Equus asinus). In IESM 2008.
Abstract: Delayed-responses have been traditionally employed to investigate the temporal characteristics of animals“ ability to represent and recall objects that have disappeared. In the typical condition, the animal, usually a mammal, observes the experimenter hiding an interesting goal (e.g. some food) in a certain location. A delayed-response task (DRT) was administered to 4 female Esperia pony (2 years old) coming from a free-range breed (Frosinone, Italy) and to 7 female Amiata donkeys (4.2±2 years old) coming from a conservation stock (University of Pisa, Italy). The DRT's apparatus was located in a square fence. A single ”U-shaped“ screen (330x160x140 cm) made by wood shavings blocks was positioned in the centre of the fence. A gap (40x50 cm) on the ground was in the middle of the central side of the U-shaped-screen and served to make the food-attractor disappear. The food-attractor consisted in cereal flakes and fresh grass for ponies and cereal flakes for donkeys. A bucket full of food was placed on a dolly tied on a rope which could be pulled by an experimenter. In a preliminary training each animal was allowed to eat food from the bucket and, while the animal was eating, the dolly was gently pulled away from the animal, and beyond the screen through the gap. The subjects needed to move around of the screen in order to retrieve the food. As a reinforcement, they were allowed to eat some food from the bucket once behind the screen. From trial to trial, the bucket was presented farther and farther (starting with a distance of 1 m in front of the screen to reach 7 m). Therefore subjects were tested in the DRT requiring them to rejoin the bucket with the goal-food disappearing behind the screen as in the preliminary training but following a 10 s delay. For the DRT, the bucket was placed 7 m in front of the screen, 3 m away from the animal's starting area. Then the dolly was pulled away from the animal. Ten seconds after the disappearance of the dolly behind the screen the animal was released from the starting area. The DRT ended when the subject had reached the attractor behind the screen on 3 consecutive trials. Results showed that all animals were able to rejoin the food behind the screen after 10 s delay. The mean time of the delayed-response (mean±sd, in s) in the ponies (1st: 19.8±8; 2nd: 10.8±2.2; 3rd: 12.8±2.8) and in the donkeys (1st: 28.4±10; 2nd: 26.9±13; 3rd: 24.3±16.6) showed a trend to decrease from first trial to third. These preliminary results suggest that like other mammals our ponies and donkeys can maintain a working memory trace of the location where biologically attractive objects have been seen to disappear. In conclusion, this study paves the way to set up a viable model system for the investigation of the more sophisticated aspects of Equids” cognitive abilities such as working memory.
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Clegg, H. A., Buckley, P., Friend, M. A., & McGreevy, P. D. (2008). The ethological and physiological characteristics of cribbing and weaving horses. Appl. Anim. Behav. Sci., 109(1), 68–76.
Abstract: Data were gathered on the behavioural and physiological characteristics of five cribbers, six weavers and six non-stereotypic (control) mature Thoroughbred geldings for a period of 16 weeks. The horses were hired from their owners and stabled individually throughout the trial. Cribbers and weavers had been known to stereotype for at least 12 months prior to commencement of the study. Behavioural data were collected using video surveillance. Cribbers stereotyped most frequently (PÂ <Â 0.001) in the period 2-8Â h following delivery of concentrated food, reinforcing the suggestion that diet is implicated in cribbing behaviour. Weavers stereotyped most frequently (PÂ <Â 0.001) during periods of high environmental activity such as during routine pre-feeding activities and in the hour prior to daily turnout, presumably when anticipation and stimulation were at their highest levels. Cribbers and weavers took longer than control horses to fully consume their ration, suggesting possible differences in motivation to feed, distress levels, satiety mechanisms or abdominal discomfort. Physiological data were collected throughout the trial and there were no differences in oro-caecal transit time, digestibility, plasma cortisol concentration or heart rate among the three behavioural groups.
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Streit, S., Zeitler-Feicht, M. H., & Dempfle, L. (2008). Gibt es in der Gruppenhaltung von Pferden bei der Abruffütterung am Automaten mehr Auseinandersetzungen als bei der Fütterung in Fressständen? [Keeping horses in groups, are there more confrontations when feeding is done with automatic feeding systems than with feeding stalls?]. In KTBL-Schriften (Vol. 471). KTBL.
Abstract: Das Droh- und Meideverhalten von 270 Pferden wurde im Fressbereich von 10 Offenlaufställen
mit Fressständen und 11 Offenlaufställen mit computergesteuerten Abrufstationen
anhand von visuellen kontinuierlichen Direktbeobachtungen erfasst. Diese erfolgten je Betrieb
über einen 24-Stunden-Tag, der nach dem Tortenstückverfahren (6x4 Stunden) zusammengesetzt
war.
Insgesamt wurden 6297 agonistische Verhaltensweisen in, vor und hinter den
Fütterungseinrichtungen registriert (Meiden 40,6 %, Verdrängen 12,8 %, Beißen/ Hinterhandschlag/
Angehen 12,7 % und Drohen/ Drohbeißen/ Hinterhanddrohen 33,9 %). In den
Futterstationen wurden 22,5 % dieses Verhaltens beobachtet, vor und hinter den Futterstationen
77,5 %. Bei den Betrieben mit Fressständen fanden 31 % der agonistischen Verhaltensweisen
in den Ständen statt, bei den Betrieben mit Abruffütterung 21 %.
Der Einfl uss des einzelnen Betriebes (innerhalb Fütterungssystem) auf die agonistischen
Verhaltensweisen vor und hinter den Fütterungseinrichtungen war signifi kant. Die Auswertung
ergab, dass Drohgesten im Wartebereich von Abrufstationen häufi ger auftreten
als in dem von Fressständen. Demgegenüber können Pferde in Abrufstationen ungestörter
fressen. Insgesamt betrachtet war jedoch die Anzahl an sozionegativen Interaktionen im
Bereich der Futtereinrichtungen bei beiden Fütterungssystemen gering. Die agonistischen
Verhaltensweisen wurden zusätzlich noch von der Heumenge und dem Konstitutionstyp
beeinfl usst.
Der Betrieb erwies sich als maßgeblicher Einfl ussfaktor. Als Resümee ergibt sich, dass
bei ordnungsgemäßer Gruppenhaltung mit fachgerechtem Management beide Fütterungssysteme
für Pferde im Offenlaufstall geeignet sind.
[The threatening and avoiding behaviour of 270 horses living in run-out sheds was observed
at 10 stables with feeding stalls and at 11 stables with automatic feeding systems for hay
and concentrates. Every group of horses was observed on five succeeding days visually
and immediately for 6 sessions, each of 4 hours. These 6 slices form together 24 hours, a
complete day.
Altogether, 6297 agonistic behaviour patterns were registered in front of, inside and
behind the feeding stations (avoiding behaviour 40.6 %, edging out of others 12.8 %,
Auseinandersetzungen an automatischer Abruffütterung und Fressständen
KTBL-Schrift 471 79
biting/rear leg kicking/charging 12.7 % und threatening/biting threats/rear leg kicking
threats 33.9 %). 22.5 % of these types of behaviour were recorded in the feeding stations,
77.5 % together in front and behind of these. In the stables with feeding stalls there were
31 % of the observed threatening gestures inside the feeding stations, in the stables with
automatic feeders only 21 %.
The individual farm showed signifi cant infl uence on the modes of agonistic behaviour
in front and behind the feeding facilities. Threatening gestures happen more often in the
waiting area of automatic feeders than in that of feeding stalls. On the other hand horses
in computer controlled systems will be less disturbed at eating. All together the number
of negative interactions in the feeding area at both feeding systems was relatively low.
In addition the agonistic behaviour was infl uenced by the quantity of hay and the constitutional
typ of the horses.
Because of the management of the individual stable exercises the most substantial
infl uence on the behaviour of the horses, it can be said, that, correct group keeping with
professional management provided, both feeding systems are suitable for horses in run-in
sheds.]
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Toewe, B., Fey, K., & Würbel, H. (2008). Effect of an omeprazole (GastroGard) treatment on cribbiting in horses suffering from gastric ulceration. In IESM 2008.
Abstract: Cribbiting is a common stereotypy in domestic horses and is associated with stress and low fibre/high concentrate diets, which are known to cause gastric inflammation and ulceration. Recent studies indicate that antacid supplements can reduce both gastric inflammation and cribbiting. However, stereotypies are also associated with altered brain functions and these are thought to be responsible for emancipation. Emancipation refers to a process by which stereotypies become increasingly independent of the causal factors and may therefore persist with age, regardless of the conditions. Emancipation complicates therapy and points to the importance of prevention.
To further examine the relationship between gastric health and cribbiting and its relation to age at onset, we examined the effect of the proton-pump inhibitor omeprazole (GastroGard, Merial) on gastric inflammation/ulceration and on cribbiting in a double-blind placebo-controlled study. Thirty-one horses of different sex, breed and age were randomly allocated to treatment and placebo and divided into three groups depending on age: 0-5 years (n=11), 5-10 years (n=11) and >10 years (n=9), whereby age at onset of cribbiting was ≤ 5 years for all horses. Treatment and placebo were administered orally by syringe once every day for 28 days by the horse owners. Treatment consisted of 4mg/kg omeprazole for the first four days and 1mg/kg for the following 24days.
Using scan sampling and behaviour sampling, general activity and the number of crib-bites were assessed in the home pens one day before and one day between day 21 and 28 of treatment. Observations were made for three hours each around morning and evening feeding times, respectively. Prior to pre-treatment observations and after post-treatment observations, the horses were transported to the clinic and endoscoped for signs of inflammation and ulceration in the oesophagus, the squamous area, the glandular area and the first part of the duodenum using a common scoring system (Andrews et al. 1999).
All 31 horses showed signs of gastric inflammation/ulceration which decreased significantly from a median score of 1,2 to 0,6 in the treatment group (Wilcoxon signed rank test, z=-3,186, p=0,001), while there was no change in the placebo group (z=-0,577, p=1.0). However, there was no significant difference in cribbiting before and after treatment, neither in the treatment group (z=-1,834, p=0,068), nor in the placebo group (z=-0,415, p=0,734). Moreover, there were no significant effects of age on gastric inflammation/ulceration (2-way ANOVA, F=1,112, p=0,345) or cribbiting (F=1,113, p=0,344).
These results contrast with the recent studies on the effects of antacids on gastric health and cribbiting. There are two possible explanations for this: First, cribbiting may become rapidly established and may thus have persisted even in the youngest age group. Second, omeprazole acts specifically by reducing gastric acid secretion into stomach, while antacids may also have an effect on the intestine. However, these results shed doubts on the hypothesis that cribbiting is caused by gastric inflammation/ulceration.
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Nagy, K., Bodó, G., Bárdos, G., & Harnos, A. (2008). Is modified Forssell"s operation superior to cribbing collar in preventing crib-biting in horses? In IESM 2008.
Abstract: Crib-biting (wind-sucking) might be a coping response of the horses to the challenges of
uncontrolled environmental events. Prevention of this stereotypic behaviour evokes
physiological responses consistent with increased stress. Reducing the incidence of cribbiting,
however, is important in order to prevent undesirable physical and behavioural
consequences (tooth erosion, altered gut function, gastric inflammation/ulceration, colic, etc.).
Common treatment of crib-biting is the application of a cribbing collar, which limits the
flexion of the neck making this stereotypic movement uncomfortable and difficult. Another
method, the modified Forssell"s operation, is becoming more and more popular amongst the
horse owners. It is based on the removal of the muscles used in crib-biting (m.omohyoideus,
m.sternohyoideus, m.sternothyrohyoideus) and the ventral branches of the spinal accessory
nerves. Surveys on the success of this surgical procedure have revealed inconsistent results,
and, contrary to the cribbing collar, its effect on the stress level have not been studied either.
The aim of our study was to determine whether the modified Forssell"s procedure is superior
to the cribbing collar treatment.
Differences in stress management was tested by a crib-biting provoking test, in which
surgically treated horses, crib-biting horses, crib-biting horses with cribbing collar, and
normal horses (those showing no stereotypies), altogether 56 horses were compared. In this
test, a food bucket had been placed out of the reach of the animal, from which titbits were
given 3 times. Behaviour and heart rate variability (HRV) of the horses were recorded and
analysed throughout the test. Hypotheses were tested by linear mixed model.
According to our results, both prevention methods (collar or surgery) inhibited crib-biting
successfully though not totally. Regarding behaviour and heart rate variability, horses
prevented from crib-biting (by collar or surgery) differed significantly from crib-biting and
normal horses but not from each other.
Normal horses were usually trying to reach the food-bucket while present and were standing
still afterwards, whereas the other three groups had not really made efforts to reach the
bucket, spent less time with resting, and performed or tried crib-biting. During the stress-test,
normal and crib-biting horses had shown good stress-adaptation to the challenge since their
HRV, after an initial increase, returned to the basal value by the end. On the contrary, HRV of
the two prevented groups remained elevated and showed large oscillations throughout. They
had not found a successful coping behaviour either.
Our results suggest that since prevention may significantly increase distress, the treatment in
itself, without changing the motivation of the horse to perform the replacement behaviour – it
seems to be unsatisfactory and insufficient. After prevention the motivation of the horse to
perform crib-biting should be addressed. In addition, considering that prevention by collar and
surgery had not resulted in any significant behavioural or physiological differences, the
superiority of the modified Forssell"s procedure might be questioned. However, the surgery
might be recommended if treatment with collar is ineffective.
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Ransom, J. I., & Cade, B. S. (2008). Influences of immunocontraception on intraband social behavior in free-ranging feral horses, Equus caballus. In IESM 2008.
Abstract: Contraception is often considered for population control of wildlife that is otherwise protected from more traditional management strategies, though little is known about the behavioral consequences of contraception in wild populations of socially complex animals. Feral horses, Equus caballus, in the western United States are ideal candidates for contraceptive management due to broad scale federal protection, reported herd growth rates of 15-25% per year, and finite public land allocated for them. We investigated influences of the immunocontraceptive porcine zona pellucida (PZP) on social behavior within bands of feral horses in three discrete populations for 4 years. Each band consisted of a single stallion and a harem of adult females (>1 years old) and their foals, as well as associated yearling males and females. Four mutually exclusive behaviors (herding, reproductive, harem tending, and agonism) were analyzed to investigate the difference between behaviors initiated by band stallions toward control mares and contracepted mares within the bands. Additionally, spatial relationships between each stallion and each harem female were analyzed to assess possible passive interactions. A candidate set of 22 hierarchical mixed effects models, using the discrete populations as a random effect on various fixed effects, was analyzed by restricted maximum likelihood estimation. The most supported models were selected by corrected Akaike"s Information Criteria (AICc). Analyses were done on 3 female age cohorts based on distinct fecundity rates: 2 to 5 year olds, 6 to 14 year olds, and > 14 year olds. Stallions herded control mares in the 6 to 14 year cohort more than contracepted mares (n=128, P=0.037) with treatment being the most supported effect, but foal presence (dependent foal) also contributed significantly to the model. Contracepted mares received more reproductive behaviors than control mares in the 6 to 14 year cohort (n = 151, P=0.020). No differences were detected in herding or reproductive behaviors in
the least fecund groups, the 2 to 5 year olds and ≥ 15 year olds. The only independent variable in the most supported model for reproductive behavior was treatment, and the covariates of foal presence, band residence (resident or transient female), band size, and body condition did not contribute. There were no differences in any age cohort for harem tending or agonism. Spatially, stallions maintained closer relationships with 2 to 5 year old contracepted females than with the same age control females (n=136, P < 0.001) while the group was feeding (at its most dispersed structure), but there were no differences while the band was resting or in locomotion. There were no spatial differences detected in the other age cohorts. Given the polyestrous nature and high fecundity of feral horses, the observed difference in reproductive behaviors between treatment groups was not surprising; however, the difference detected in herding rates was an unexpected behavioral modification. This change in herding behavior suggests that further investigation is needed to determine if PZP immunocontraception has an underlying influence on mare social rank, band structure, and band stability, as well as the scope and long-term importance of these behavioral dynamics.
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Slingerland, L. I., Robben, J. H., Schaafsma, I., & Kooistra, H. S. (2008). Response of cats to familiar and unfamiliar human contact using continuous direct arterial blood pressure measurement. Research in Veterinary Science, 85(3), 575–582.
Abstract: Continuous direct measurement of feline arterial blood pressure (ABP) was carried out via a modified method with percutaneous, ultrasound guided catheterization of the common carotid artery. In 21 healthy, conscious cats the ABP was measured during rest, alertness and activity. Furthermore, the ABP response to being petted by familiar and unfamiliar persons was assessed. Linear mixed modelling revealed that the mean blood pressure (MBP) in resting cats (114.6 mmHg) was lower (P < 0.001) than in alert cats (122.7 mmHg), which was lower (P < 0.001) than that of active cats (136.8 mmHg). The MBP during petting by a familiar person (144.7 mmHg) tended to be higher (P = 0.065) than that during petting by an unfamiliar person (139.4 mmHg). The MBP of active cats was lower (P = 0.003) than MBP of cats petted by a familiar person, but not different from MBP of cats petted by an unfamiliar person. The MBP returned to resting values between 16 and 20 min after the familiar person had left, whereas resting values were reached between 11 and 15 min after the unfamiliar person had left. The complications of the described method were limited considering the potential risks of continuous direct ABP measurement. In conclusion, the described technique enables accurate measurement of feline ABP, which is influenced by the cat's activity level and the familiarity of persons.
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Bertolucci, C., Giannetto, C., Fazio, F., & Piccione, G. (2008). Seasonal variations in daily rhythms of activity in athletic horses. Animal, 2(07), 1055–1060.
Abstract: Circadian rhythms reflect extensive programming of biological activity that meets and exploits the challenges and opportunities offered by the periodic nature of the environment. In the present investigation, we recorded the total activity of athletic horses kept at four different times of the year (vernal equinox, summer solstice, autumn equinox and winter solstice), to evaluate the presence of seasonal variations of daily activity rhythms. Athletic Thoroughbred horses were kept in individual boxes with paddock. Digitally integrated measure of total activity of each mare was continuously recorded by actigraphy-based data loggers. Horse total activities were not evenly distributed over the day, but they were mainly diurnal during the year. Daily activity rhythms showed clear seasonal variations, with the highest daily amount of activity during the vernal equinox and the lowest during the winter solstice. Interestingly, the amount of activity during either photophase or scotophase changed significantly throughout the year. Circadian analysis of horse activities showed that the acrophase, the estimated time at which the peak of the rhythm occurs, did not change during the year, it always occurred in the middle of the photoperiod. Analysing the time structure of long-term and continuously measured activity and feeding could be a useful method to critically evaluate athletic horse management systems in which spontaneous locomotor activity and feeding are severely limited. Circadian rhythms are present in several elements of sensory motor and psychomotor functions and these would be taken into consideration to plan the training schedules and competitions in athletic horses.
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