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Bartosova, J., Komarkova, M., Dubcova, J., Bartos, L., & Pluhacek J. (2012). Nursing behaviour in pregnant domestic mares (Equus caballus): Can they cope with dual maternal investment? In K. Krueger (Ed.), Proceedings of the 2. International Equine Science Meeting (Vol. in press). Wald: Xenophon Publishing.
Abstract: Among mammals, lactation is the most energy demanding part of parental care and so parentoffspring conflict should arise over milk provided by the mother. Mother and offspring should disagree over the length and amount of the milk provision. We focused on effect of pregnancy on suckling behaviour variables as indicators of mother-offspring conflict in domestic horses. We presumed shorter suckling bouts and higher rates of rejected and/or terminated suckling in pregnant mares compared to non-pregnant ones. Increasing conflict over amount of maternal investment between mother and her young are to be expected because of her parallel investment into a nursed foal and a foetus. Eight groups of loose housed lactating mares with foals of Kladruby horse were studied at the National Stud Kladruby nad Labem (Czech Republic) from deliveries to abrupt weaning (at the age of 127 to 210 days). We recorded 10 848 suckling solicitations of 79 mare-foal pairs, from which 10 607 resulted in a suckling bout. In 41 cases a nursing mare became pregnant during lactation. We found no significant effect of pregnancy either on probability of the mother rejecting suckling solicitation of her foal or probability that she terminated a suckling bout. However the overall effect of mother’s pregnancy on suckling bout duration was not significant, there were considerable differences in pregnant and non-pregnant mares according to who terminated a suckling bout, whether the mother or the foal (F(1, 9776) = 12.1, P < 0.001). In case it was the mother then the suckling bout was longer if she was pregnant (65.36 ± 1.25 s) than barren (60.55 ± 1.36 s). We found no impact of pregnancy on duration of suckling bouts terminated by the foal. Further, nursing a foal during the first two trimesters of pregnancy had no negative impact on birth weight of the foetus. In conclusion, we found not higher, but a lower mother-offspring conflict in pregnant than in non-pregnant lactating mares while expecting just the opposite. We suggest that pregnant mares compensate their nursed foals during intensive stages of lactation through a relaxed mother-offspring conflict for later decrease in investment due to increasing demands of the foetus and/or for the shorter period of milk supply. Our results (partly published in Bartosova et al. 2011, PLoS ONE 6(8): e22068) are of high importance in horse breeding. One of the main arguments for early weaning of the foals is regeneration of their pregnant mothers before upcoming delivery. Here we present evidence that a pregnant mare “counts” with her dual maternal investment and “employs” evolutionary mechanisms enabling her to rear a vital foetus. From this point of view there is no objective reason for stressful weaning of her nursed offspring practised in conventional breeding. Supported by AWIN, EU FP7 project No. 266213.
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Baumgartner M. (2012). Liegeverhalten von Pferden im Offenlaufstall auf unterschiedlichen Bodenmaterialien (Gummimatten, Späne und Sand) [Recumbency patterns of horses stabled in group housing systems on different bedding materials (rubber mats, shavings and sand)]. Ph.D. thesis, , Munich.
Abstract: Die angemessenste Art ein Pferd als soziales Wesen unter menschlicher Obhut zu halten, ist in der Gruppe mit Seinesgleichen. Dabei gilt der Offenlaufstall mit getrennten Funktionsbereichen (Mehrraum-Außenlaufstall mit Auslauf) als die tiergerechteste Haltungsform für Pferde (BMELV, 2009). Aus Gründen der Arbeits- und Kostenersparnis sowie zur Reduzierung der Keim- und Staubbelastung werden in jüngster Zeit vermehrt Gummimatten als Einstreuersatz in Liegehallen von Offenlaufställen eingesetzt.
In vorliegender Arbeit sollte überprüft werden, ob Gummimatten (7,5 cm hoch, schaumstoffgefüllt; HIT-Softbed plus®) in Kombination mit minimaler Späneeinstreu als Liegeunterlage in Liegehallen von Offenlaufställen als tiergerecht beurteilt werden können. Darüber hinaus galt es zu klären, ob die Klimaverhältnisse in den Liegehallen trotz nicht saugfähiger Gummiunterlage den hygienischen Anforderungen des BMELVs (2009) an das Stallklima entsprechen. Dazu wurde das Liegeverhalten von einer repräsentativen Anzahl von 56 Pferden in einem Offenlaufstall mit getrennten Funktionsbereichen an jeweils 6 Tagen je Jahreszeit (Frühling, Sommer, Herbst, Winter) mittels kontinuierlicher Videoaufzeichnungen (n= 24 Tage) und zusätzlichen visuellen Direkt-beobachtungen (n= 60 Std) erfasst. Die Pferde hatten zum Liegen die Wahl zwischen folgenden drei Arealen: drei identisch ausgestatteten, jedoch unterschiedlich großen Liegehallen (mittig Gummimatten; Randbereich Späneeinstreu), einem Unterstand (Sand), sowie einem Sandplatz. Die Größe der Liegefläche in den drei Liegehallen (LH I 172 m², LH II und III jeweils 143 m²) entsprach den Anforderungen des BMELVs (2009). Unterstand und Sandplatz konnten zusätzlich von den Pferden zum Ruhen im Liegen genutzt werden. Ergänzend wurden folgende Einflussfaktoren auf das Liegeverhalten der Pferde erfasst: Tageszeit, Jahreszeit und Witterung sowie Alter, Stockmaß, Gewicht, „Body Condition Score“ und Rangordnung. Durchschnittlich ruhten lediglich 35,2 der 52,3 in der Anlage befindlichen Pferde (67,3%) pro Beobachtungstag im Liegen in den Arealen. Demzufolge nahmen Zusammenfassung 213 viele Pferde nicht jede Nacht eine Liegeposition ein. Die Hauptliegezeit mit 72% der erfassten Liegephasen war zwischen 0 und 6 Uhr. Bezogen auf die vorhandene Liegefläche je Areal ergab sich lediglich eine 50%ige Maximalauslastung an gleichzeitig liegenden Pferden. Die Liegephasendauer variierte -unabhängig vom Areal- signifikant zwischen den Pferden (p=0,028) und darüber hinaus auch je Pferd (p<0,001). Die durchschnittliche Dauer pro Liegephase war mit 28,8 ± 0,5 (SEM) min signifikant länger in den Liegehallen (I, II und III), als im Unterstand mit 24,6 ± 0,9 min und auf dem Sandplatz mit 20,0 ± 1,9 min (p<0,001). Die mittlere tägliche Gesamtliegedauer eines Pferdes betrug 91 ± 2,7 min in den Liegehallen (I, II und III), 43 ± 2,3 min im Unterstand und 27 ± 2,9 min auf dem Sandplatz (p<0,001). In den Liegehallen legte sich ein Pferd im Mittel 3,2 Mal am Tag ab, im Unterstand lediglich 1,7 und auf dem Sandplatz 1,3 Mal (p<0,001). 79% der registrierten Liegephasen (n= 2410) fanden darüber hinaus in den Liegehallen (I, II und III) statt, was deren zentrale Bedeutung als Liegebereich hervorhebt. In der größeren Liegehalle I ruhten eine größere Anzahl an unterschiedlichen Pferden häufiger (p<0,0002) und länger (p<0,0005) pro Tag im Liegen als in den beiden etwas kleineren Liegehallen II und III. Die tägliche Gesamtliegedauer pro Pferd war mit aufgestütztem Kopf mit 54,8 ± 1,6 Minuten länger als ohne aufgestützten Kopf mit 45,2 ± 1,8 min. In Seitenlage wurde im Durchschnitt pro Tag und Pferd 27,5 ± 1,1 min geruht (p<0,001). Diese Ruheposition wurde in den Liegehallen signifikant häufiger eingenommen, als auf dem Sandplatz oder im Unterstand (p<0,001). Die tägliche mittlere Gesamtliegedauer pro Pferd auf Späne war mit 74,3 ± 2,9 min gegenüber 62,4 ± 2,3 min auf Gummimatten signifikant länger (p=0,005). Ebenso fanden in Relation zum Flächenangebot in den Liegehallen geringfügig mehr Liegephasen auf dem Späne-Bereich als auf den Gummimatten statt. Ebenfalls in Flächenrelation wurde der offen gestaltete Unterstand deutlich vor den anderen Arealen zum Ruhen im Liegen von den Pferden präferiert. Es sei deshalb auf die Bedeutung eines Unterstandes als zusätzliche Liegefläche in Offenlaufstallhaltung hingewiesen. Die meisten Liegephasen und auch die längsten täglichen Liegezeiten fanden in den warmen Monaten statt (p=0,013). Im Winter flachte das Ruhen im Liegen deutlich ab und verlagerte sich bei unter -10°C nahezu ausschließlich auf die Liegehallen (p=0,001). Der leichte Späne-Überzug und der positive Effekt der bereits integrierten und die Gummimatten zum Liegen nutzenden Pferde waren mögliche Gründe dafür, dass die Neuankömmlinge ohne Gummimatten-Vorerfahrung (n= 10 Pferde ≤ 6 Monate in der Anlage) kein vermindertes Liegeverhalten im Vergleich zur bestehenden Herde (n= 46 Pferde; mind. 1 bis max. 3 J. in der Anlage) aufwiesen. Die Rangordnung wurde mittels modifiziertem „Average Dominance Index“ berechnet. Die rangniederen Pferde hatten mit 2,6 gegenüber 3,4 und 3,1 sowohl signifikant weniger Liegephasen pro Pferd und Tag, als auch mit 69,3 ± 3,9 min eine um 22 min signifikant kürzere tägliche Gesamtliegedauer als die Ranghöheren (jeweils p<0,001). Rangniedrige Pferde ruhten in den Liegehallen weniger häufig (2,7 gegenüber 3,5 und 3,2 mittlere Anzahl Liegephasen/ Pferd/ Tag) und auch signifikant (p<0,001) kürzer je Tag (77,8 ± 5,0 min gegenüber 97,3 ± 3,9 min und 98,8 ± 5,1 min). Je jünger ein Pferd war, desto öfter (3,5 gegenüber 2,6 mittlere Anzahl Liegephasen/ Pferd/ Tag) und länger (103,7 ± 7,6 min gegenüber 56,1 ± 13,2 min) legte es sich am Tag nieder, und desto häufiger (90% der Liegephasen der 4 und 5 Jährigen gegenüber 39% und 70% der 16 bis 25 J.) nutzte es die Liegehallen zum Liegen (p<0,001). Das Stockmaß der Pferde und das Pferdegewicht zeigten keinen eindeutigen Einfluss auf das Liegeverhalten. Für den „Body Condition Score“ (Skala 1 bis 9) ergaben sich signifikante Unterschiede. Je höher der BCS der Pferde war, desto häufigere (p=0,0185) und längere Liegezeiten (p=0,007) wiesen sie auf. Der monatlich gemessenen Ammoniakgehalt sowie Luftgeschwindigkeit, Luftfeuchtigkeit und Temperatur entsprachen bei Einsatz von Gummimatten in den Liegehallen den Anforderungen des BMELV (2009) an ein tiergerechtes Stallklima. Voraussetzung hierfür ist jedoch eine ausreichende Luftzirkulation im Stallgebäude sowie eine gute Stallhygiene. Die Ergebnisse aus den vergleichenden Beobachtungen der unterschiedlichen Liegematerialien lassen schlussfolgern, dass die hier untersuchten verformbaren Gummimatten in Kombination mit minimaler Späneeinstreu in Offenlaufställen von der Mehrzahl der Pferde zum Ruhen im Liegen angenommen wurde und deshalb als weitgehend tiergerecht beurteilt werden können. [Being highly social animals, horses are housed most adequately in groups. Loose housing systems are said to be the most species adequate system of horse housing (BMELV, 2009). Recently rubber mats have increasingly been used instead of shavings as bedding in loose housing systems where the different functional areas are separated. Advantages of rubber mats are that they are less cost and labour intensive as shavings, and their use also reduces the bacterial and dust contamination of the environment. However, it has not yet been shown whether horses are capable of satisfying their recumbency needs on rubber mats as well as they can on shavings. This study looks to clarify this question, as well as to evaluate the hygienic conditions of the stabling climate in the areas equipped with sponge-filled rubber mats (HIT-Softbed® plus). The recumbency patterns of 56 horses kept in a loose housing system with separate functional areas were observed on 6 days per season (spring, summer, autumn and winter) using wide angle video cameras. The different areas were: three similar but different large halls meant as lying areas (in the middle rubber mats; in the periphery shavings), an unsheltered area with sand footing and a sheltered area with sand footing. The size of the three halls meant as lying areas (LH I 172 m², LH II and III each 143 m²) was adequate with the demands of the BMELV (2009). Confounding factors which could also affect recumbency behaviour, such as day time, season and weather were taken into account. The role of the horses rank was also investigated. The occurrence of disruptions during recumbency phases by other members of the herd was also found out. Horse specific factors such as age, height, weight and body condition score were also taken into account as these could also have an effect on recumbency patterns. On each day of observation, in average 35 different horses out of 56 horses (65%) were seen to be resting in a recumbent position. Hence many horses did not assume a recumbent position every night. Seventy-two percent of the recumbency phases occurred between 0 and 4 am. The capacity of the area for a lying position at one time offered the horses was only exploited to 50%. The length of the recumbency phase varied significantly between animals and for the individual animals over the duration of the observation period (p<0.001). The average recumbent time per lying phase was 28.8 ± 0.5 (SEM) minutes in the halls (I, II and III), 24.6 ± 0.9 min in the shelter and 20.0 ± 1.9 min on the sand area. The average time spent lying down per horse per day was 91 ± 2.7 min in the halls, 43 ± 2.3 min in the shelter and 27 ± 2.9 min on the sand area (p<0.001). The horses lay down an average of 3.2 times in the halls, 1.7 times in the shelter and 1.3 times in the sand area (p<0.001). Seventy-nine percent of the observed recumbency phases (n= 2410) were seen in the halls. This shows that along with the pastures, the halls played a central role in the recumbency patterns of the horses. When comparing the halls, a wider variety of horses was observed spending a longer time in recumbency (p<0.0005) more often (p<0.0002) in hall I than in the somewhat smaller halls II and III. The total time spent per day in recumbency with the head supported was 54.8 ± 1.6 min and hence was ten minutes longer than the total daily time spent in recumbency without the head supported with 45.2 ± 1.8 min. On average the horses spent 27.5 ± 1.1 min in lateral recumbency (p<0.001). Horses were observed to lie in lateral recumbency more often in the halls than on sand area or in the shelter (p<0.001). The daily total length of time spent in recumbency was found to be significantly longer on bedding (74.3 ± 2.9 min) versus on rubber mats (62.4 ± 2.3 min) (p=0.005). Even though the average number and length of recumbency periods per day and horse, as well as the average time spent in lateral recumbency was greater for the halls, when taking surface area into consideration, it was found that the sheltered area was used the most per surface area for resting in recumbency. Hence it is relevant to state the importance of a shelter as additional lying space in loose housing systems. The highest number of recumbency phases and the longest time spent daily lying down were seen in the mild months of the year (p=0.013). Temperatures below freezing led to decreased recumbency behavior. The horses observed lay down almost exclusively in the halls when temperature was below -10°C (p<0.001). The newcomers (n= 10 horses ≤ 6 months in the stable) to this housing system did not show a diminished recumbency behaviour compared to the other horses (n= 46 horses for 1 to 3 years in the stable). It is apparent that horses that do not have previous experience of rubber mats do not necessitate an adaptation period to use the mats to lay down on, as long as they are introduced into a group of horses that are already comfortable with the use of the mats. Likewise the shavings could help the horses adapt to the new material faster. The rank of the horse in the herd was determined using a modified “Average Dominance Index”. The horses of low rank showed a significantly lower number of recumbency phases (2.6 compared to 3.4 and 3.1 per horse per day), as well as with 69.3 ± 3.9 min a highly significant shorter by 22 minutes length of recumbency phase when compared to horses of higher rank (each p<0.001). With diminishing rank, the horses lay down less frequently in the halls (2.7 compared to 3.5 and 3.2 recumbency phases per horse per day) and the total daily time spent in recumbency (77.8 ± 5.0 min compared to 97.3 ± 3.9 min und 98.8 ± 5.1 min) diminished significantly (p<0.001). Younger horses were found to lie down more frequently (3.5 compared to 2.6 recumbency phases per horse per day) but also to spend significantly longer periods (103.7 ± 7.6 min compared to 56.1 ± 13.2 min) in recumbency (p<0.001). Younger horses also tended to (90% of recumbency phases of 4 and 5 year old compared to 39% and 70% of 16 until 25 year old) use the halls for recumbent periods of rest (p<0.001). Horse height and weight did not influence recumbency behavior clearly. An interesting correlation was however noted with “body condition score” (BCS). A scale from 1 to 9 was used. The higher the BCS, the more (p=0.0185) and longer (p=0.007) time the animal spent resting in recumbency. Air ammonia content, air velocity, ambient humidity and temperature measured monthly were within the recommendations of the BMELV (2009). Rubber mats are of no concern to hygiene when used as bedding in loose housing systems with segregated functional areas, as long as sufficient air circulation and proper stable hygiene are present. The results of the comparative observations of the various bedding materials lead us to conclude that the currently studied rubber mats in combination with a minimum amount of shaving are accepted by the majority of the horses and therefore are a widely species-appropriate bedding material for horses in loose housing systems.] |
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Becker-Birck, M., Biau, S., Aurich, C., Möstl, E., Ille, N., & Aurich, J. (2012). Heart rate and heart rate variability in the horse and its rider: different responses to training and a public equestrian performance. In K. Krueger (Ed.), Proceedings of the 2. International Equine Science Meeting (Vol. in press). Wald: Xenophon Publishing.
Abstract: While detailed information exists on the cardiovascular response of horses to racing or endurance, much less is known about cardiovascular function of the rider in equestrian sports. Combined analysis of the horse-rider-team has not been investigated so far. In this study, we have analyzed changes in heart rate and heart variability (HRV) variables SDRR (standard deviation of beat-to-beat interval) and RMSSD (root mean square of successive beat-to-beat intervals) both in well-trained horses (n=9) and their highly experienced riders (n=7) during the airs above the ground (sauteurs en liberté of the Cadre noir de Saumur) at a public performance and at an identical, but non-public training session, both lasting for exactly 7 min. Heart rate in the horses and riders increased during the airs above the ground, both in training and in the public performance (p<0.001 over time). In the horses, this increase did not differ between training and public performance (training: from 35±6 in the stable to 97±17 beats/min during riding, performance: from 43±13 to 103±13 beats/min, respectively). In contrast, in the riders, the increase in heart rate was significantly more pronounced (p<0.01) during the public performance (basal value 91±10, maximum 150±15 beats/min) than during training (basal value 94±10, maximum 118±12 beats/min). With regard to HRV in horses, overall SDRR did not change significantly over time and did not differ significantly between training and performance. RMSSD decreased during both training and performance to the same extent, indicating a decrease in parasympathetic (vagal) tone. In the riders, both HRV variables decreased significantly during riding (p<0.001) and for SDRR the decrease was more pronounced (p<0.05) during an equestrian performance compared to a training session. During the performance SDRR decreased from a basal value of 5.0±1.5 to a minimum of 3.2±0.6 msec while respective values for the training session were 5.3±1.1 and 2.3±1.1 msec. Both a public performance and an identical training session of the airs above the ground in the ridden horse caused an increase in heart rate and a decrease in HRV variables. While increases in heart rate are mainly caused by physical activity, decreases in HRV also indicate a stress response. The cardiovascular response in the horses did not differ between a training session and a public performance but clear differences could be demonstrated in the riders. During a public performance, the increase in heart rate and decrease in SDRR were more pronounced than during a similar training session. In conclusion, the presence of an audience thus causes more pronounced sympathoadrenal activity in experienced riders than the same equestrian tasks ridden without spectators present. In contrast, the presence of an audience was without effect on sympathoadrenal activity in experienced horses. KW -
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Belock, B., Kaiser, L. J., Lavagnino, M., & Clayton, H. M. (2012). Comparison of pressure distribution under a conventional saddle and a treeless saddle at sitting trot. The Veterinary Journal, 193(1), 87–91.
Abstract: It can be a challenge to find a conventional saddle that is a good fit for both horse and rider. An increasing number of riders are purchasing treeless saddles because they are thought to fit a wider range of equine back shapes, but there is only limited research to support this theory. The objective of this study was to compare the total force and pressure distribution patterns on the horse’s back with conventional and treeless saddles. The experimental hypotheses were that the conventional saddle would distribute the force over a larger area with lower mean and maximal pressures than the treeless saddle. Eight horses were ridden by a single rider at sitting trot with conventional and treeless saddles. An electronic pressure mat measured total force, area of saddle contact, maximal pressure and area with mean pressure >11 kPa for 10 strides with each saddle. Univariate ANOVA (P < 0.05) was used to detect differences between saddles. Compared with the treeless saddle, the conventional saddle distributed the rider’s bodyweight over a larger area, had lower mean and maximal pressures and fewer sensors recording mean pressure >11 kPa. These findings suggested that the saddle tree was effective in distributing the weight of the saddle and rider over a larger area and in avoiding localized areas of force concentration.
Keywords: Horse; Rider; Equitation; Tack; Electronic pressure mat
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Ben-Shlomo, G., Plummer, C., Barrie, K., & Brooks, D. (2012). Characterization of the normal dark adaptation curve of the horse. Veterinary Ophthalmology, 15(1), 42–45.
Abstract: Objective The goal of this work is to study the dark adaptation curve of the normal horse electroretinogram (ERG). Procedures The electroretinographic responses were recorded from six healthy female ponies using a contact lens electrode and a mini-Ganzfeld electroretinographic unit. The horses were sedated intravenously with detomidine, an auriculopalpebral nerve block was then performed, and the pupil was fully dilated. The ERG was recorded in response to a low intensity light stimulus (30 mcd.s/m2) that was given at times (T) T = 5, 10, 15, 20, 25, 30, 40, 50, and 60 min of dark adaptation. Off-line analysis of the ERG was then performed. Results Mean b-wave amplitude of the full-field ERG increased continuously from 5 to 25 min of dark adaptation. The b-wave amplitude peaked at T = 25, however, there was no statistical significance between T = 20 and T = 25. The b-wave amplitude then remained elevated with no significant changes until the end of the study at T = 60 (P > 0.49). The b-wave implicit time increased continuously between T = 5 and T = 20, then gradually decreased until T = 60. No distinct a-wave was observed during the testing time. Conclusions Evaluation of horse rod function or combined rod/cone function by means of full-field ERG should be performed after a minimum 20 min of dark adaptation.
Keywords: adaptation; curve; dark; electroretinography; equine; scotopic
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Benson-Amram, S., & Holekamp, K. E. (2012). Innovative problem solving by wild spotted hyenas. Proc R Soc B, 279, 4087–4095.
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Berger, A., & Wolfram, M. (2012). How to come together best? – Studies on integration processes of Przewalski horses into new groups (Equus ferus przewalskii). In K. Krueger (Ed.), Proceedings of the 2. International Equine Science Meeting (Vol. in press). Wald: Xenophon Publishing.
Abstract: Conservation of endangered species in zoos and other protected areas has saved several species from extinction. The Przewalski horse (Equus ferus przewalskii) is one of that species and, being an attractive large ungulate, it is a “flagship species” for conservation projects. Reintroduction into its former habitat is accompanied by many difficulties and is a great challenge. Semireserves have been defined as enclosures large enough to maintain groups of Przewalski horses throughout all seasons of the year without any supplemental provisioning. The animals are kept isolated from external human influences as far as possible, except for necessary interventions such as veterinary care. Hence, the purpose is not limited to preparing animals for survival under natural conditions, but is equally related to the need to gain experience in establishment of free-ranging populations. Naturally, horses live in groups in which all individuals are long-term acquainted with each other and a stable hierarchical system is established. In conservation management an integration of horses into strange groups is often need but at the same time implies social fights, stress and risks for the animals. We investigated the integration process of 4 Przewalski horses from Zoo Leipzig into the herd of 5 Przewalski horses in the semireserve Liebenthal (Brandenburg, Germany). Before transportation the social structure was determined in both the herd in Zoo Leipzig and in Liebenthal. After transportation the social hierarchy and the individual dominance indices were determined by daily observation. Continuous records of activity and feeding were taken from several individuals using the ETHOSYS-storage telemetry system. The automatically recorded behaviours were analysed for daily and ultradian rhythms and used for stress detection by calculating a value (DFC) representative for regularity and stability of rhythmic structures. In zoo conditions, the behaviour was very regular and the daily pattern nearly identical from day to day as expressed by DFC´s near of 100%. After transportation, the behaviour became much less regular, DFC´s dropped significantly, recovered slowly and stabilised on values typically for semireserve conditions. Social bindings and dominances of the former two herds were mainly retained. As an important result, long lasting and stepwise transition from zoo to natural habitats with special training using new observing techniques can be strongly recommended.
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Blanco, J. C., & Yolanda, C. (2012). Surveying wolves without snow: a critical review of the methods used in Spain. Hystrix. Ital J Mammal, 23.
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Bouskila, A., de Vries, H., Hermans, Z. M., & van Dierendonck, M. (2012). Leadership roles in movements of free-roaming Konik horses (Equus caballus) in a Dutch reserve. In K. Krueger, & (Ed.), Proceedings of the 2. International Equine Science Meeting (Vol. in press). Wald: Xenophon Publishing.
Abstract: We observed the activity and movements of Konik horses (Equus caballus) in order to determine the initiators of movements and the individuals taking the lead in movements of the main groups. We conducted our observations between March-June 2010 along the shores of the Rhine river, in the Blauwe Kamer reserve, in the Netherlands. The horses were introduced to the reserve alongside with cattle to prevent the growth of the forest and maintain the grass habitat. We videotaped all observations on two digital video cameras, one providing the general view of the group and the other scanning and focusing on the individuals, to aid with identification. Horses were recognized based on individual profiles that were created for each one, consisting of photos of both sides and notes of the main characters, such as orientation and coloration of the mane, prominent scars and markings, etc. Twenty three horses (not counting foals) were organized in two harem groups with 11 individuals (two of which were dominant stallions) in the large group and six individuals (one of which was a stallion) in the second group. These two main groups were always within sight of each other, and two bachelor males moved usually in their vicinity. An additional group of three young bachelor males roamed elsewhere in the reserve. We divided the movements of the horses to local movements while grazing and to long-distance movements, in which the horses moved to a different grazing location, to a pond of water, resting area or groups of trees that were used by the horses for scratching themselves. During the local movements, any two of the three oldest females in the large harem group were enough to cause the whole group to follow them and gradually change position within the pasture. The smaller harem always followed the large harem’s movements. The long-distance movements of the large harem were sometimes initiated by one of the harem stallions that herded their group and at other times – by the oldest females. Soon after the movement was clearly initiated, the dominant stallions positioned themselves in the back of the group or in the center and had no influence on the direction of move that was only determined by the leading females. In the long-distance movements too, the small harem followed the large harem group, and the two bachelor males usually followed behind them. Social interactions included aggressive interactions between the two dominant males within the large harem or between dominant stallions and the two bachelor males accompanying the two harems. In addition, dominant males courting or attempting to mate with mares sometimes caused a turmoil that eventually initiated movement of the harems. KW -
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Bouskila, A., Renan, S., Speyer, E., Ben-Natan, D., Zaibel, I., & Bar-David, S. (2012). Group composition and behavior of reintroduced Equus hemionus near a water source in the Negev Desert. In K. Krueger (Ed.), Proceedings of the 2. International Equine Science Meeting (Vol. in press). Wald: Xenophon Publishing.
Abstract: The Asiatic Wild Ass, Equus hemionus, was once abundant in western Asia. The species declined due to hunting and habitat loss. Between 1982-93 38 E. hemionus (21? 17?) that originated from Iran and Turkmenistan were reintroduced to the Negev Desert, Israel. Saltz, Rubinstein and co-workers studied the released population till 1999. The current population in the Negev is estimated at more than 200 individuals, yet, their social and genetic structures are not known. Here we report group composition and behavior of E. hemionus near a water sources from the 2010 and 2011 field seasons, which is part of a wider study of the mating system and genetic diversity. We recorded and videotaped group composition and social interactions from a shelter, 150m from the water source. We recorded a total of 377 observations, in which 251 only males were observed, in 105 observations we observed females and juveniles, and only in 21 cases we observed a mixed group of females with at least one male. Not all wild asses were individually identified, but so far, we analyzed data from 69 individual profiles (based on photos), and recorded in which groups were they videotaped. Before reaching the water source, wild asses often aggregate in large groups and wait for the first few individuals to approach cautiously the water, and only then the rest of the individuals make a swift final approach. We did not consider these aggregations as social groups. We defined a group when individuals approached or left together the valley in which the water source is located. In a few encounters between E. hemionus and wolves (around sunset) we noticed that the wild asses showed interest in the wolves and increased alertness, but the wolves did not approach the equids under these conditions. Female groups (including those with a male) were larger than male-only groups (range 2-49 and 1-34, respectively; P =0.0191). From records of individuals observed more than once, individuals appear on different days in groups of various sizes and compositions, suggesting a social structure with a certain degree of fission-fusion. The mean proportion of juveniles per female was 0.57 and this value is higher than the average found in the 1990’s study (0.5). Apart from the proliferation of the population, an important difference between the earlier and the current study stems from the fact that the E. hemionus in the Negev Desert expanded their range and it includes now the Negev Highlands, an area with slightly more mesic and stable conditions. Except for Sep., fewer adult females were observed compared to males (P=0.028). Different daily activity patterns of the two sexes may explain this observation. These results will be combined with the genetic work and will contribute to the assessment of population viability.
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