toggle visibility Search & Display Options

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author Cant, M.A.; Field, J. doi  openurl
  Title Helping effort in a dominance hierarchy Type Journal Article
  Year 2005 Publication Behavioral Ecology Abbreviated Journal Behav. Ecol.  
  Volume 16 Issue 4 Pages 708-715  
  Keywords  
  Abstract In many cooperatively breeding species, group members form a dominance hierarchy or queue to inherit the position of breeder. Models aimed at understanding individual variation in helping behavior, however, rarely take into account the effect of dominance rank on expected future reproductive success and thus the potential direct fitness costs of helping. Here we develop a kin-selection model of helping behavior in multimember groups in which only the highest ranking individual breeds. Each group member can invest in the dominant's offspring at a cost to its own survivorship. The model predicts that lower ranked subordinates, who have a smaller probability of inheriting the group, should work harder than higher ranked subordinates. This prediction holds regardless of whether the intrinsic mortality rate of subordinates increases or decreases with rank. The prediction does not necessarily hold, however, where the costs of helping are higher for lower ranked individuals: a situation that may be common in vertebrates. The model makes two further testable predictions: that the helping effort of an individual of given rank should be lower in larger groups, and the reproductive success of dominants should be greater where group members are more closely related. Empirical evidence for these predictions is discussed. We argue that the effects of rank on stable helping effort may explain why attempts to correlate individual helping effort with relatedness in cooperatively breeding species have met with limited success.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium (up)  
  Area Expedition Conference  
  Notes 10.1093/beheco/ari051 Approved no  
  Call Number refbase @ user @ Serial 760  
Permanent link to this record
 

 
Author Vahl, W.K.; Lok, T.; van der Meer, J.; Piersma, T.; Weissing, F.J. url  doi
openurl 
  Title Spatial clumping of food and social dominance affect interference competition among ruddy turnstones Type Journal Article
  Year 2005 Publication Behavioral Ecology Abbreviated Journal Behav. Ecol.  
  Volume 16 Issue 5 Pages 834-844  
  Keywords  
  Abstract In studying the success of foraging animals, studies of interference competition have put emphasis on effects of competitor density, whereas studies of resource defense have focused on the effects of the spatial distribution of food within patches. Very few studies have looked at both factors simultaneously, that is, determined whether the effects of competitor density on foraging success depend on the spatial distribution of food. We studied the behavior and the foraging success of ruddy turnstones (Arenaria interpres) using an experiment in which we varied both the presence of a competitor and the food distribution. Because turnstones may differ strongly in their relative dominance status, we also experimentally varied the foragers' relative dominance status. We found that the presence of a competitor only reduced the foraging success of subordinate birds foraging at the clumped food distribution. At this condition, dominant and subordinate birds differed markedly in their foraging success. Contrary to our expectations, we did not observe more agonistic behavior at the clumped food distribution. This indicates that the amount of agonistic behavior observed may be a bad indicator of interference effects. These findings have specific implications for models of interference competition. Most notably they show that the effects of competitor density on agonistic behavior and foraging success may well depend on the spatial distribution of food and the foragers' relative dominance status. Additionally, our results suggest that social dominance will not be fully understood without considering long-term processes such as the formation and maintenance of social dominance hierarchies.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium (up)  
  Area Expedition Conference  
  Notes 10.1093/beheco/ari067 Approved no  
  Call Number refbase @ user @ Serial 761  
Permanent link to this record
 

 
Author Haring, H. openurl 
  Title Development, level and prospects of the german horse breeding Type Journal Article
  Year 2005 Publication Zuechtungskunde Abbreviated Journal Zuechtungskunde  
  Volume 77 Issue 6 Pages 490-495  
  Keywords Breeding program; Breeding/Member association; Change of structure; Estimation of breeding values; Fédération Equestre Nationale (FN)/German Equestrian Federation; Step of selection; Equidae; Equus caballus  
  Abstract The economic impact of the horses of the Federal Republic of Germany has gone up, the statistic numerals verify obviously that Germany took pride of place in Europe in terms of numbers of riders as well as numbers of horses. Successes of German branded horses let their breeders reach the summit worldwide. The carefully agreed breeding programme connects practical cognitions with those of science and permits the leading breeding areas unobstructed space to set their own priorities. Globalisation and rised demand of customers forces breeding associations towards a far-reaching reorganisation because just large powerful institutions can meet these requirements. An end of this process, which scarcely has just begun, cannot yet be conceivable seen. – Eugen Ulmer KG, Stuttgart.  
  Address Deutsche Reiterliche Vereinigung e. V., 48229 Warendorf, Germany  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 00445401 (Issn) ISBN Medium (up)  
  Area Expedition Conference  
  Notes Cited By (since 1996): 1; Export Date: 21 April 2007; Source: Scopus; Language of Original Document: German; Correspondence Address: Haring, H.; Deutsche Reiterliche Vereinigung e. V. 48229 Warendorf, Germany; email: Hharing@fn-dokr.de Approved no  
  Call Number refbase @ user @ Serial 791  
Permanent link to this record
 

 
Author Lansade, L.; Bertrand, M.; Bouissou, M.-F. doi  openurl
  Title Effects of neonatal handling on subsequent manageability, reactivity and learning ability of foals Type Journal Article
  Year 2005 Publication Applied Animal Behaviour Science Abbreviated Journal Appl. Anim. Behav. Sci.  
  Volume 92 Issue 1-2 Pages 143-158  
  Keywords Horse; Neonatal handling; Manageability; Emotional reactivity; Learning-ability; Human-animal relationship  
  Abstract Behaviour is an important factor to be taken into account in the various uses of horses. Today horses are mainly used for sport and leisure activities. They should therefore be easy to manage, calm and not fearful. Early handling is known to improve manageability and learning ability and to reduce fearfulness in various species. It has become fashionable in the horse industry to use an early training procedure, referred to as “imprint training”, which is said to produce durable if not permanent effects. However, no studies concerning the long-term effects of such neonatal handling have been carried out in horses. The present study examines the short- and long-term effects of neonatal handling on manageability, general reactivity and learning ability of foals. Twenty-six Welsh foals were studied: 13 were handled daily for 14 days from birth and 13 were non-handled controls. The handling procedure consisted of fitting a halter, gently patting all parts of each foal's body, picking up feet and leading over 40 m. Two days, 3 months, 6 months and 1 year after the end of the handling period, foals underwent behavioural tests to measure their manageability and various aspects of their reactivity. The results showed that neonatal handling has only short-term effects on manageability: 2 days after the handling period, handled animals were significantly easier to handle than controls for the four parameters measured during this test (time to fit a halter, time to pick up feet, walk ratio that is time during which foal walks under constraint/total time measured during leading and number of defensive reactions). Two parameters (time to fit a halter and walk ratio) were still lower in handled foals than in non-handled foals 3 months later and only one 6 months later (walk ratio). One year later there was no difference between groups. In addition, there was no effect of handling on reactivity at any time of testing or in any of the tests (reaction to isolation from conspecifics, presence of a human, presence of a novel object and to a surprise effect). Finally, neonatal handling did not improve the spatial or discriminative learning abilities measured at 14 months of age. To conclude, the effects of neonatal handling are only temporary.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium (up)  
  Area Expedition Conference  
  Notes Approved no  
  Call Number refbase @ user @ Serial 841  
Permanent link to this record
 

 
Author Uehara, T.; Yokomizo, H.; Iwasa, Y. doi  openurl
  Title Mate-choice copying as Bayesian decision making Type Journal Article
  Year 2005 Publication The American naturalist Abbreviated Journal Am Nat  
  Volume 165 Issue 3 Pages 403-410  
  Keywords Animals; *Bayes Theorem; *Choice Behavior; Female; Male; *Models, Biological; *Sexual Behavior, Animal  
  Abstract Mate-choice copying by females has been reported in fishes (e.g., guppies) and lekking birds. Presumably, females assess males' quality using both information from direct observation of males and information acquired by observing other females' choices. Here, we study mathematically the conditions under which mate-choice copying is advantageous on the basis of Bayesian decision theory. A female may observe the mate choice of another female, called the model female, who has performed an optimal choice based on her own judgment. The conditions required for the focal female to choose the same mate as that chosen by the model female should depend on the male's appearance to her, the reliability of her own judgment of male quality, and the reliability of the model females. When three or more females are involved, the optimal mate choice critically depends on whether multiple model females make decisions independently or they themselves copy the choices of others. If two equally reliable females choose different males, the choice of the second female, made knowing the choice of the first, should have a stronger effect on the choice of the third (focal) female. This “last-choice precedence” should be tested experimentally.  
  Address Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan. uehara@bio-math.biology.kyushu-u.ac.jp  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1537-5323 ISBN Medium (up)  
  Area Expedition Conference  
  Notes PMID:15729669 Approved no  
  Call Number Serial 1821  
Permanent link to this record
 

 
Author McGreevy, P.D.; Rogers, L.J. doi  openurl
  Title Motor and sensory laterality in thoroughbred horses Type Journal Article
  Year 2005 Publication Applied Animal Behaviour Science Abbreviated Journal Appl. Anim. Behav. Sci.  
  Volume 92 Issue 4 Pages 337-352  
  Keywords Horse; Lateralisation; Training; Olfaction; Forelimb preference  
  Abstract We investigated lateralisation in horses because it is likely to be important in training and athletic performance. Thoroughbred horses (n = 106) were observed every 60 s for 2 h, when they were at pasture, and the position of the forelimbs in relation to one another was recorded. There was a population bias skewed to standing with the left forelimb advanced over the right (i.e. directional lateralisation). Using the first 50 observations, the distribution of preferences was 43 significantly left, 10 significantly right with 53 being non-significant (i.e. ambidextextrous). The strength of motor bias increased with age, suggesting maturation or an influence of training. The horses were also presented with an olfactory stimulus (stallion faeces) to score the tendency to use one nostril rather than the other. A significant preference to use the right nostril first was shown in horses under 4 years of age (n = 61) but not in older horses. Of the 157 horses tested for nostril bias, 76 had been assessed for motor bias and so were used for analysis of the relationship between laterality in the two modalities. There was no significant relationship between direction of foreleg motor bias and first nostril used, total number of inhalations or laterality index of nostril use. The absence of a correlation between laterality of nostril use and motor bias indicates that lateralisation of the equine brain occurs on at least two levels of neural organisation--sensory and motor--a finding that is consistent with other examples of lateralisation in species that have been examined in more detail.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium (up)  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ room 3.029 Serial 1827  
Permanent link to this record
 

 
Author Bobbert, M.F.; Santamaria, S. doi  openurl
  Title Contribution of the forelimbs and hindlimbs of the horse to mechanical energy changes in jumping Type Journal Article
  Year 2005 Publication The Journal of Experimental Biology Abbreviated Journal J Exp Biol  
  Volume 208 Issue 2 Pages 249-260  
  Keywords Animals; Biomechanics; Forelimb/*physiology; Hindlimb/*physiology; Horses/*physiology; Locomotion/*physiology; Muscle, Skeletal/*physiology; Time Factors  
  Abstract The purpose of the present study was to gain more insight into the contribution of the forelimbs and hindlimbs of the horse to energy changes during the push-off for a jump. For this purpose, we collected kinematic data at 240 Hz from 23 5-year-old Warmbloods (average mass: 595 kg) performing free jumps over a 1.15 m high fence. From these data, we calculated the changes in mechanical energy and the changes in limb length and joint angles. The force carried by the forelimbs and the amount of energy stored was estimated from the distance between elbow and hoof, assuming that this part of the leg behaved as a linear spring. During the forelimb push, the total energy first decreased by 3.2 J kg(-1) and then increased again by 4.2 J kg(-1) to the end of the forelimb push. At the end of the forelimb push, the kinetic energy due to horizontal velocity of the centre of mass was 1.6 J kg(-1) less than at the start, while the effective energy (energy contributing to jump height) was 2.3 J kg(-1) greater. It was investigated to what extent these changes could involve passive spring-like behaviour of the forelimbs. The amount of energy stored and re-utilized in the distal tendons during the forelimb push was estimated to be on average 0.4 J kg(-1) in the trailing forelimb and 0.23 J kg(-1) in the leading forelimb. This means that a considerable amount of energy was first dissipated and subsequently regenerated by muscles, with triceps brachii probably being the most important contributor. During the hindlimb push, the muscles of the leg were primarily producing energy. The total increase in energy was 2.5 J kg(-1) and the peak power output amounted to 71 W kg(-1).  
  Address Institute for Fundamental and Clinical Human Movement Sciences, Vrije Universiteit, van der Boechorstraat 9, NL-1081 BT Amsterdam, The Netherlands. MFBobbert@fbw.vu.nl  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-0949 ISBN Medium (up)  
  Area Expedition Conference  
  Notes PMID:15634844 Approved no  
  Call Number Serial 1895  
Permanent link to this record
 

 
Author Robert, N.; Walzer, C.; Ruegg, S.R.; Kaczensky, P.; Ganbaatar, O.; Stauffer, C. doi  openurl
  Title Pathologic findings in reintroduced Przewalski's horses (Equus caballus przewalskii) in southwestern Mongolia Type Journal Article
  Year 2005 Publication Journal of zoo and Wildlife Medicine : Official Publication of the American Association of Zoo Veterinarians Abbreviated Journal J Zoo Wildl Med  
  Volume 36 Issue 2 Pages 273-285  
  Keywords Animals; Babesiosis/epidemiology/pathology/*veterinary; Cause of Death; Conservation of Natural Resources; Disease Susceptibility/veterinary; Environment; Female; Food Chain; Horse Diseases/*epidemiology/pathology; Horses; Male; Mongolia/epidemiology; Streptococcal Infections/epidemiology/pathology/*veterinary; *Streptococcus equi; Theileriasis/*epidemiology/pathology; Weather  
  Abstract The Przewalski's horse (Equus caballus przewalskii) was extinct in the wild by the mid 1960s. The species has survived because of captive breeding only. The Takhin Tal reintroduction project is run by the International Takhi Group; it is one of two projects reintroducing horses to the wild in Mongolia. In 1997 the first harem group was released. The first foals were successfully raised in the wild in 1999. Currently, 63 Przewalski's horses live in Takhin Tal. Little information exists on causes of mortality before the implementation of a disease-monitoring program in 1998. Since 1999, all dead horses recovered (n = 28) have been examined and samples collected and submitted for further investigation. Equine piroplasmosis, a tick-transmitted disease caused by Babesia caballi or Theileria equi, is endemic in Takhin Tal and was identified as the cause of death of four stallions and one stillborn foal. In December 2000, wolf predation was implicated in the loss of several Przewalski's horses. However, thorough clinical, pathologic, and bacteriologic investigations performed on dead and surviving horses of this group revealed lesions compatible with strangles. The extreme Mongolian winter of 2000-2001 is thought to have most probably weakened the horses, making them more susceptible to opportunistic infection and subsequent wolf predation. Other occasional causes of death since 1999 were trauma, exhaustion, wasting, urolithiasis, pneumonia, abortion, and stillbirth. The pathologic examination of the Przewalski's horses did not result in a definitive diagnosis in each case. Several disease factors were found to be important in the initial phase of the reintroduction, which could potentially jeopardize the establishment of a self-sustaining population.  
  Address Center for Fish and Wildlife Health, Institute of Animal Pathology, University of Berne, Langgass-Strasse 122, CH-3001 Berne, Switzerland  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1042-7260 ISBN Medium (up)  
  Area Expedition Conference  
  Notes PMID:17323569 Approved no  
  Call Number Serial 2023  
Permanent link to this record
 

 
Author Dumont, B.; Boissy, A.; Achard, C.; Sibbald, A.M.; Erhard, H.W. url  doi
openurl 
  Title Consistency of animal order in spontaneous group movements allows the measurement of leadership in a group of grazing heifers Type Journal Article
  Year 2005 Publication Applied Animal Behaviour Science Abbreviated Journal Appl. Anim. Behav. Sci.  
  Volume 95 Issue 1-2 Pages 55-66  
  Keywords Cattle; Grazing; Leadership; Movement order; Walking  
  Abstract The term `leadership' has been used in several different senses, resulting in very different ways of identifying leaders and apparently inconsistent conclusions on how leadership is determined in herbivores. We therefore propose the following definitions: (i) a leader is the individual that is consistently the one who initiates long-distance, spontaneous group movements toward a new feeding site and (ii) long-distance spontaneous group movements are movements which happen when an animal changes activity and location and is immediately followed by a similar change in activity and location by other members of the group. Using these definitions, we tested for consistency of movement order across time and situation within a group of fifteen 2-year-old heifers. We found that the same individual was recorded as the very first animal in 48% of movements toward a new feeding site and could therefore be identified as the `leader'. We also showed that movement order when the animals entered an experimental plot, or progressed slowly through the field during a grazing bout, did not produce the same result. This method, which enables us to identify leaders in groups of animals at pasture, should improve our knowledge of how leadership is determined in grazing herbivores.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium (up)  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ room B 3.029 Serial 2027  
Permanent link to this record
 

 
Author Dall, S.R.X.; Giraldeau, L.-A.; Olsson, O.; McNamara, J.M.; Stephens, D.W. doi  openurl
  Title Information and its use by animals in evolutionary ecology Type Journal Article
  Year 2005 Publication Trends in Ecology & Evolution (Personal Edition) Abbreviated Journal Trends Ecol Evol  
  Volume 20 Issue 4 Pages 187-193  
  Keywords  
  Abstract Information is a crucial currency for animals from both a behavioural and evolutionary perspective. Adaptive behaviour relies upon accurate estimation of relevant ecological parameters; the better informed an individual, the better it can develop and adjust its behaviour to meet the demands of a variable world. Here, we focus on the burgeoning interest in the impact of ecological uncertainty on adaptation, and the means by which it can be reduced by gathering information, from both 'passive' and 'responsive' sources. Our overview demonstrates the value of adopting an explicitly informational approach, and highlights the components that one needs to develop useful approaches to studying information use by animals. We propose a quantitative framework, based on statistical decision theory, for analysing animal information use in evolutionary ecology. Our purpose is to promote an integrative approach to studying information use by animals, which is itself integral to adaptive animal behaviour and organismal biology.  
  Address Centre for Ecology and Conservation, University of Exeter in Cornwall, Tremough Campus, Penryn, UK, TR10 9EZ. sashadall@iname.com  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0169-5347 ISBN Medium (up)  
  Area Expedition Conference  
  Notes PMID:16701367 Approved no  
  Call Number Serial 2128  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print