HFWU Home

Equine and Animal Cognition Reference Database

Home |  Show All |  Simple Search |  Advanced Search
Quick Search:
91-100 of 203 records found matching your query:
toggle visibility Search & Display Options
Select All    Deselect All << 1 2 3 4 5 6 7 8 9 10 >> [11–20]
List View
 | 
Citations
 | 
Details
   print
  Records Links
Author Sondergaard, E.; Halekoh, U. url  openurl
  Title Young horses' reactions to humans in relation to handling and social environment Type Journal Article
  Year 2003 Publication Applied Animal Behaviour Science Abbreviated Journal Appl. Anim. Behav. Sci.  
  Volume 84 Issue 4 Pages 265-280  
  Keywords Horses; Human-animal relationship; Social environment; Handling  
  Abstract (up) Forty Danish warmblood colts in two replicates were used to investigate the effect of housing and handling in the rearing period on the reactions to humans. The horses entered the experiment after weaning and were housed either individually (n=16) or in groups of three (n=24). Half of the horses from each housing group were handled three times per week for a period of 10 min. Approach tests were performed in the home environment when the horses were 6, 9, 12, 18, 21, and 24 months old, and an Arena and Human Encounter test was performed in a novel environment when the horses were 12 and 24 months old, respectively. In the home environment, single-housed horses approached sooner and were more easily approached by a human than group-housed horses where no effect of handling was observed. Horses approached sooner and were more easily approached with increasing age. In the Arena and Human Encounter test, single-housed horses expressed less restless behaviour, more explorative behaviour, and less vocalisation than group-housed horses. Handled horses showed lower increase in heart rate during the test than non-handled horses. There was no difference between the number of times single or group-housed horses touched an unfamiliar person in the Arena and Human Encounter test but handled horses approached sooner than non-handled horses. It is concluded that the social environment affected the way horses reacted to humans when tested in the home environment but not in a novel environment. In contrast, handling affected the reactions to humans when tested in the novel environment but not in the home environment. However, handled horses also reacted less to the novel environment in general, thus indicating that handling is a mean of avoiding potential dangerous situations.  
  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  
  Area Expedition Conference  
  Notes Approved no  
  Call Number refbase @ user @ Serial 308  
Permanent link to this record
 
 
Author McCall, C.A.; Salters, M.A.; Johnson, K.B.; Silverman, S.J.; McElhenney, W.H.; Lishak, R.S. url  openurl
  Title Equine utilization of a previously learned visual stimulus to solve a novel task Type Journal Article
  Year 2003 Publication Applied Animal Behaviour Science Abbreviated Journal Appl. Anim. Behav. Sci.  
  Volume 82 Issue 3 Pages 163-172  
  Keywords Horse; Learned stimulus; Novel task; Discrimination  
  Abstract (up) Forty-four horses were used to determine if a learned stimulus could be used to increase acquisition of a response unrelated to the original learned task. Horses were paired by age, breed and sex. One randomly chosen horse from each pair served as the control while the remaining horse was trained to respond to a visual stimulus by pushing a lever to obtain a food reward. In Experiment I (n=28), the food reward was delivered in a feed box located equidistant between two levers located 2.7 m apart on one wall of the test stall. Trained horses were given 30 training trials daily until they achieved at least 85% correct responses in three nonconsecutive days. After each trained horse reached criterion, both horses in the pair were tested in 30 trials daily for five consecutive days in a modified Y maze. The stimulus that indicated the correct lever in the initial training task was used to signify the correct arm of the maze for both the control and trained horses. The correct arm of the maze was changed randomly during each daily session, and correct choices resulted in a food reward. In Experiment II (n=16), levers were located on opposite walls (11 m apart) of the test stall, and the stimulus and modified Y maze were simplified. Trained horses received 15 training trials daily until they reached at least 85% correct responses on three consecutive days. As each trained horse achieved this criterion, both horses in the pair were tested in a maze for 15 trials daily for 7 days. Again, the stimulus from initial lever-pressing task was used to signify the rewarded arm of the maze. Correct choices of trained and control horses in both experiments were compared using a paired t-test. In Experiment I, no differences (P>0.34) in mean correct responses were detected between trained and control horses on the first day in the maze (15.3 and 16.8, respectively) or after 5 days in the maze (84.0 and 82.1, respectively). Similarly, in Experiment II, trained and control horses did not differ (P>0.50) in mean correct responses on the first day (6.9 and 7.4, respectively) or after 7 days in the maze (63.6 and 61.6, respectively). These results indicate that the stimuli used to solve the lever-pressing task were not utilized by horses in the maze task, and that horses may have difficulty transferring learned visual stimuli to new tasks.  
  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  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 3587  
Permanent link to this record
 
 
Author Vonk, J. doi  openurl
  Title Gorilla ( Gorilla gorilla gorilla) and orangutan ( Pongo abelii) understanding of first- and second-order relations Type Journal Article
  Year 2003 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 6 Issue 2 Pages 77-86  
  Keywords Animals; *Cognition; Color Perception; Female; Gorilla gorilla/*psychology; Male; Pongo pygmaeus/*psychology; Task Performance and Analysis  
  Abstract (up) Four orangutans and one gorilla matched images in a delayed matching-to-sample (DMTS) task based on the relationship between items depicted in those images, thus demonstrating understanding of both first- and second-order relations. Subjects matched items on the basis of identity, color, or shape (first-order relations, experiment 1) or same shape, same color between items (second-order relations, experiment 2). Four of the five subjects performed above chance on the second-order relations DMTS task within the first block of five sessions. High levels of performance on this task did not result from reliance on perceptual feature matching and thus indicate the capability for abstract relational concepts in two species of great ape.  
  Address York University, 4700 Keele Street,Toronto, ON M3J 1P3, Canada. jxv9592@louisiana.edu  
  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 1435-9448 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:12687418 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2578  
Permanent link to this record
 
 
Author Zentall, T.R.; Clement, T.S.; Weaver, J.E. openurl 
  Title Symmetry training in pigeons can produce functional equivalences Type Journal Article
  Year 2003 Publication Psychonomic bulletin & review Abbreviated Journal Psychon Bull Rev  
  Volume 10 Issue 2 Pages 387-391  
  Keywords Animals; Association; Behavior, Animal; Columbidae; Conditioning (Psychology)/*physiology; Teaching/*methods; *Transfer (Psychology)  
  Abstract (up) Functional stimulus equivalence has been demonstrated using a transfer of training design with matching-to-sample training in which two sample stimuli are associated with the same comparison stimulus (A-B, C-B; many-to-one matching). Equivalence is shown by training a new association (A-D) and demonstrating the presence of an emergent relation (C-D). In the present experiment, we show that symmetry training, in which a bidirectional association is trained between two stimuli (A-B, B-A, using successive stimulus presentations followed by reinforcement), can also produce functional equivalence using a transfer of training design (i.e., train B-C, test A-C). The results suggest that training pigeons in the substitutability of two stimuli may be sufficient to produce functional stimulus equivalence between them. The results also have implications for the development of an emergent transitive relation, because training on A-B and B-C relations results in the emergence of an untrained A-C relation, if B-A training also is provided.  
  Address Department of Psychology, University of Kentucky, Lexington, Kentucky 40506-0044, USA. zentall@pop.uky.edu  
  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 1069-9384 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:12921414 Approved no  
  Call Number refbase @ user @ Serial 235  
Permanent link to this record
 
 
Author Conradt, L.; Roper, T.J. url  doi
openurl 
  Title Group decision-making in animals Type Journal Article
  Year 2003 Publication Nature Abbreviated Journal Nature  
  Volume 421 Issue 6919 Pages 155-158  
  Keywords Animals; Behavior, Animal/*physiology; *Decision Making; Democracy; Group Processes; *Models, Biological; Population Density; Social Behavior  
  Abstract (up) Groups of animals often need to make communal decisions, for example about which activities to perform, when to perform them and which direction to travel in; however, little is known about how they do so. Here, we model the fitness consequences of two possible decision-making mechanisms: 'despotism' and 'democracy'. We show that under most conditions, the costs to subordinate group members, and to the group as a whole, are considerably higher for despotic than for democratic decisions. Even when the despot is the most experienced group member, it only pays other members to accept its decision when group size is small and the difference in information is large. Democratic decisions are more beneficial primarily because they tend to produce less extreme decisions, rather than because each individual has an influence on the decision per se. Our model suggests that democracy should be widespread and makes quantitative, testable predictions about group decision-making in non-humans.  
  Address School of Biological Sciences, University of Sussex, Brighton BN1 9QG, UK. l.conradt@sussex.ac.uk  
  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 0028-0836 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:12520299 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5136  
Permanent link to this record
 
 
Author Natalini, C.C.; Robinson, E.P. openurl 
  Title Effects of epidural opioid analgesics on heart rate, arterial blood pressure, respiratory rate, body temperature, and behavior in horses Type Journal Article
  Year 2003 Publication Veterinary Therapeutics : Research in Applied Veterinary Medicine Abbreviated Journal Vet Ther  
  Volume 4 Issue 4 Pages 364-375  
  Keywords 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer/administration & dosage/pharmacology; Alfentanil/administration & dosage/pharmacology; Analgesics, Opioid/administration & dosage/*pharmacology; Anesthesia, Epidural/*veterinary; Animals; Behavior, Animal/drug effects; Blood Pressure/drug effects; Body Temperature/drug effects; Butorphanol/administration & dosage/pharmacology; Cross-Over Studies; Female; Heart Rate/drug effects; Horses/*physiology; Injections, Epidural/veterinary; Male; Morphine/administration & dosage/pharmacology; Respiration/drug effects; Tramadol/administration & dosage/pharmacology  
  Abstract (up) Heart rate, arterial blood pressures, respiratory rate, body temperature, and central nervous system excitement were compared before and after epidural administration of morphine (0.1 mg/kg), butorphanol (0.08 mg/kg), alfentanil (0.02 mg/kg), tramadol (1.0 mg/kg), the k-opioid agonist U50488H (0.08 mg/kg), or sterile water using an incomplete Latin square crossover design in five conscious adult horses. Treatments were administered into the first intercoccygeal epidural space. Significant (P <.05) reductions in respiratory rate were detected after epidural administration of morphine, alfentanil, U50488H, and sterile water. Additionally, significant (P <.05) head ptosis was observed within the first hour after administration of morphine, U50488H, and tramadol, but neither of these changes appeared to be of clinical significance. No treatment-related changes in motor activity or behavior were observed.  
  Address Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA  
  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 1528-3593 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:15136978 Approved no  
  Call Number Serial 1902  
Permanent link to this record
 
 
Author Barker, S.C. openurl 
  Title The Australian paralysis tick may be the missing link in the transmission of Hendra virus from bats to horses to humans Type Journal Article
  Year 2003 Publication Medical Hypotheses Abbreviated Journal Med Hypotheses  
  Volume 60 Issue 4 Pages 481-483  
  Keywords Animals; Chiroptera; *Disease Transmission; Ecology; Hendra Virus/*pathogenicity; Horses; Humans; Models, Theoretical; Polymerase Chain Reaction; Ticks/*virology  
  Abstract (up) Hendra virus is a new virus of the family Paramyxoviridae. This virus was first detected in Queensland, Australia, in 1994; although, it seems that the virus has infected fruit-eating bats (flying-foxes) for a very long time. At least 2 humans and 15 horses have been killed by this virus since it first emerged as a virus that may infect mammals other than flying-foxes. Hendra virus is thought to have moved from flying-foxes to horses, and then from horses to people. There is a reasonably strong hypothesis for horse-to-human transmission: transmission of virus via nasal discharge, saliva and/or urine. In contrast, there is no strong hypothesis for flying-fox-to-human transmission. I present evidence that the Australian paralysis tick, Ixodes holocyclus, which has apparently only recently become a parasite of flying-foxes, may transmit Hendra virus and perhaps related viruses from flying-foxes to horses and other mammals.  
  Address Department of Microbiology and Parisitology, Institute for Molecular Biosciences, ARC Special Research Center for Functional and Applied Genomics, The University of Queensland, Brisbane, Australia. s.barker@imb.uq.edu.au  
  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 0306-9877 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:12615503 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2641  
Permanent link to this record
 
 
Author Seyfarth, R.M.; Cheney, D.L. openurl 
  Title Meaning and emotion in animal vocalizations Type Journal Article
  Year 2003 Publication Annals of the New York Academy of Sciences Abbreviated Journal Ann N Y Acad Sci  
  Volume 1000 Issue Pages 32-55  
  Keywords Acoustics; *Affect; Animals; Behavior, Animal; *Intention; Posture; Sound Spectrography; *Vocalization, Animal  
  Abstract (up) Historically, a dichotomy has been drawn between the semantic communication of human language and the apparently emotional calls of animals. Current research paints a more complicated picture. Just as scientists have identified elements of human speech that reflect a speaker's emotions, field experiments have shown that the calls of many animals provide listeners with information about objects and events in the environment. Like human speech, therefore, animal vocalizations simultaneously provide others with information that is both semantic and emotional. In support of this conclusion, we review the results of field experiments on the natural vocalizations of African vervet monkeys, diana monkeys, baboons, and suricates (a South African mongoose). Vervet and diana monkeys give acoustically distinct alarm calls in response to the presence of leopards, eagles, and snakes. Each alarm call type elicits a different, adaptive response from others nearby. Field experiments demonstrate that listeners compare these vocalizations not just according to their acoustic properties but also according to the information they convey. Like monkeys, suricates give acoustically distinct alarm calls in response to different predators. Within each predator class, the calls also differ acoustically according to the signaler's perception of urgency. Like speech, therefore, suricate alarm calls convey both semantic and emotional information. The vocalizations of baboons, like those of many birds and mammals, are individually distinctive. As a result, when one baboon hears a sequence of calls exchanged between two or more individuals, the listener acquires information about social events in its group. Baboons, moreover, are skilled “eavesdroppers:” their response to different call sequences provides evidence of the sophisticated information they acquire from other individuals' vocalizations. Baboon males give loud “wahoo” calls during competitive displays. Like other vocalizations, these highly emotional calls provide listeners with information about the caller's dominance rank, age, and competitive ability. Although animal vocalizations, like human speech, simultaneously encode both semantic and emotional information, they differ from language in at least one fundamental respect. Although listeners acquire rich information from a caller's vocalization, callers do not, in the human sense, intend to provide it. Listeners acquire information as an inadvertent consequence of signaler behavior.  
  Address Departments of Psychology and Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA. seyfarth@psych.upenn.edu  
  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 0077-8923 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:14766619 Approved no  
  Call Number refbase @ user @ Serial 688  
Permanent link to this record
 
 
Author Wasilewski A. url  openurl
  Title 'Friendship' in ungulates? – Sociopositive relationships between non-related herd members of the same species Type Manuscript
  Year 2003 Publication Abbreviated Journal  
  Volume Issue Pages  
  Keywords  
  Abstract (up) http://www.staff.uni-marburg.de/~z-phylog/wisstaff/wasi-sum.htm

Summary

* The quantitative study presented here demonstrates and verifies for ungulates the existence of social bonds, which in humans are termed 'friendships'. Whereas 'friendships' in non-human primates have become increasingly accepted over the past 30 years, their existence in non-primates remained as yet to be proved.

* The investigation was conducted on ungulates, because like primates the majority of their species are highly social; at the same time they are phylogenetically distant to the primates. To date, research into the social behaviour of ungulates in general, and of domestic species in particular, focuses predominantly on agonistic (socionegative) components, such as conflicts and resulting dominance hierarchies; sociopositive behaviours have been largely neglected.

As a consequence, previous evidence in favour of 'friendships' among ungulates remained largely anecdotal. Studies explicitly investigating sociopositive relationships among herd members are rare and typically confound bonds based on 'friendships' with reproductive relationships (kinship and sexually motivated bonds).

* Of each of the two large ungulate orders two species were investigated: horses and donkeys (Perissodactyla, Equidae) and sheep and cattle (Artiodactyla, Bovidae). The comparative, individual-based (and hence highly discriminative) longitudinal approach addressed all three levels of social organisation: associations, interactions and bond patterns within social units. Due to its systematic, quantitative, individual-based and comparatively broad design, this work may be considered to some degree a 'pioneering study'. As a consequence, a substantial amount of time and effort was required, particularly with respect to developing methods for the collection and analysis of data.

* Two reasons led to conducting this study on domestic ungulates: For farm animals information about who is related to whom is usually readily available, facilitating discrimination between friendship and kinship. Furthermore, successful proof of 'friendships' among ungulates would imply practical consequences for animal husbandry, since a social environment accommodating the animals' psychosocial needs is an essential prerequisite for their well-being (ethical reasons for animal protection) and ultimately results in higher productivity and hence economic efficiency (anthropocentric reasons for animal protection).

* Field research was conducted in England. Cattle and sheep were studied under commercial husbandry conditions, whereas appropriately large herds of horses and donkeys could only be found at a sanctuary.

* Two to three herds of each of the four species, namely cattle, sheep, donkeys and horses, comprising 11 to 60 members (average herd size approx. 25) were studied in two consecutive years (1996: 36 weeks, 1997: 28 weeks). The herds of cattle mainly consisted of subadult females, whereas those of the other species were predominantly composed of adults. Equids were kept in mixed-sex herds of mares and geldings (castrated males); the bachelor flocks of sheep consisted of 'intact' males (rams). The data presented here are based on 234 individuals and approximately 1500 hours of observation.

* Since even human social psychology provides neither a consistent definition nor a universally applicable terminology, it was necessary to establish a generally valid, precise definition of 'friendship'. Care was taken to exclude characteristics containing a bias as to the function of friendships (criteria were limited to those regarding contents and form). The definition contains all relevant criteria including those necessary for discrimination against alternative sociopositive relationships.



Friendship is defined as a voluntary, reciprocal, non-reproductive bond between individuals. It is primarily dyadic and carries a subjective value to both participants. Friendship is characterised by positive affect ('affection') and is expressed in a consistent inter-individual preference.

This definition is applicable to social relationships among both human and non-human animals, as well as interspecific relationships.

* Two types of parameters were used as indicators of 'friendship': frequency of spatial proximity (nearest neighbours; consistent neighbour preferences as a reflection of associations) and frequencies of different spontaneous as well as experimentally induced sociopositive interactions. For different reasons, of the four kinds of interactions (social grooming s.l., resting in physical contact, sharing limited feed, documenting behaviours s.l.) only grooming and feed sharing proved reliable.

* Aspects of the animals' spontaneous behaviour were recorded for all herds and in both years, whereas husbandry conditions demanded that complementary experiments be restricted to a few selected herds only. Data were collected using different Sampling and Recording Techniques, which were usually combined for maximum efficiency (e.g. Scan Sampling with nearest neighbour data, Ad libitum Sampling and Continuous Recording with sociopositive interactions).

* Data were subjected to an extensive statistical analysis. In addition to commonly used uni- and bivariate methods (Binomial and Chi-Square Goodness-of-Fit Tests, bivariate Correlations and Mantel Tests) a number of multivariate statistics were applied (Multidimensional Scaling, hierarchical Cluster Analysis, partial Correlations and multiple Mantel-Tests). Dyadic data are best represented as matrices; matrix data, however, pose the difficulty of partial interdependence, requiring Randomisation Tests (such as the one developed by Mantel) for their analysis. The complexity and amount of neighbour data required the development and optimisation of a 'customised' evaluation software (NENESYS = NEarest NEighbour SYstematic Standardisation programme) in close interdisciplinary cooperation with computer scientists and mathematicians.

* Seven different aspects of 'ungulate friendships' were addressed. The presented results differ in extent and depth.

1. Demonstration and verification of friendships in ungulates

2. Quantification of inter-individual preferences

3. Situation-specific aspects of these preferences

4. Dynamics and duration of friendships

5. Asymmetry within the relationships

6. Conditions enhancing friendships

7. Functions of animal friendships

* All four species expressed distinct inter-individual ('personal') preferences both for certain neighbours and for specific partners for sociopositive interactions. Endeavouring to present conservative and hence reliable assessments, only those neighbour preferences exceeding a threshold criterion were considered as associations. As the set-up of the study ensured that these associations met the criteria outlined in the definition of 'friendship' by excluding alternative bases for bonds (such as kinship and sexual motivation = reproductive relationships), the first explicit attempt at verifying the existence of friendship can be considered successful for all four species of ungulates examined. As a consequence, the concept of 'friendship' needs to be extended beyond the order of primates.

* Due to methodological reasons, the frequencies of interactions are only semi-quantitative and hence can be compared within herds only.

Frequencies of spatial proximity, on the other hand, provide a fully quantitative indicator, enabling direct comparisons across species, between different herds of the same species and between individuals. Due to the 'spatial limitations' of this thesis, it mainly focuses on inter-species comparisons.

With the exception of donkeys, the species could be arranged in sequence of increasing values of three parameters characterising their associative structure: maximum strength of association, maximum group size and proportion of herd members associated in distinct groups. Cattle showed the lowest values in all three parameters, sheep were intermediate, and horses reached the highest values. In these three species the strength of their associations was positively related to group size and the proportion of individuals associated in distinct groups. The donkeys did not fit this pattern: On the one hand, their association pattern comprised the lowest proportion of associated members and the smallest groups (pairs); on the other hand, these pairs exhibited very strong associations.

* Comparing inter-individual preferences across up to four different situations clear interspecific differences became evident. Some of these were greater between species of the same order than between orders.

The comparison of structures of association during grazing to those during resting, revealed two distinct patterns: Herds of horses and sheep flocks divided themselves into separate, usually mutually exclusive and independent groups and their associations corresponded greatly in both situations. Donkeys and cattle, on the other hand, formed diffuse, incomplete associative networks. The proportion of associations corresponding in both situations was far lower than in horses and sheep.

In all four species frequencies of social grooming s.l. (sheep are generally believed not to engage in social grooming, but see below) were compared to proximity frequencies during grazing and resting; and additionally to frequencies of feed sharing in the equid species.

Whereas horses restricted their sociopositive interactions entirely (grooming) or mostly (feed sharing) to members of their own group, cattle showed very little if any correspondence between partner preferences when grazing, resting and grooming. Donkeys spread their preferences widely across herd members, 'typically' approaching individuals for grooming with whom they were not associated during either grazing or resting. Considering their patterns of feed sharing, two different types of behaviour became evident: Pairs of donkeys that were closely associated during both grazing and resting, preferentially shared feed between them, whereas the remaining herd members did not discriminate between associates and non-associates when sharing feed. For sheep the findings of this study substantially increased the likelihood that unidirectional head rubbing and reciprocal cheek-to-cheek contact serve to strengthen 'personal' bonds and reduce tension – two functions generally attributed to social grooming. Both behaviours occurred mostly, but not exclusively, within groups of associated animals; these associations corresponded largely during grazing and resting.

* Results indicate that different types of social interactions and associations during different activities, respectively, may be particularly suited to initiate, consolidate and intensify friendships and occur particularly frequently during different phases of friendship formation and development. In horses, for instance, social grooming appears to some extent to be associated with the initiation of bonds, whereas resting in close proximity seems to strengthen newly formed relationships.

The longitudinal character of the study permitted to trace existing bonds over a maximum of 18 months. The duration of bonds in horses and sheep was comparable to findings of other authors for herds whose social networks resulted from a mixture of bonds based on both friendship and kinship; cattle relationships lasted shorter than described in the literature, while those in donkeys turned out to be approximately twice as long as had been documented to date.

* Aspects of asymmetry within dyadic relationships become particularly evident in grooming behaviours in bovids, which are typically performed unilaterally (social licking in cattle and head rubbing in sheep). Both behaviours can occur either spontaneously or as a consequence of solicitation.

* Addressing the question of factors potentially encouraging friendships, relationships between the degree of similarity with respect to some physical characteristics and nearest neighbour frequencies were found to be statistically significant. Cattle of similar age associated more closely, and horned rams preferred other individuals with horns as neighbours. The widely accepted preference of horses for associates of similar coat colour (and height) was not verified.

It remains to be decided whether (in addition to this preference for similar individuals) a preference based on complementary characteristics does exist.

* Following a critical review of the methodology employed, the benefits ungulates derive from friendships and possible applications for animal husbandry are discussed. Very little convincing evidence of a (direct) concrete, practical benefit was found. A psychological benefit in the form of social / emotional support, on the opposite, became highly probable.

Anecdotal evidence indicates, that situations causing a state of anxiety, may favour the initiation and intensification of friendships. Moreover, the study was able to statistically prove connection between (roughly) simultaneous introduction to a new herd (novel social environment) and persisting associations (as an indicator of friendships) in horses and sheep. These findings suggest that ungulate friendships provide a feeling of security. Social / emotional support among friends is predominantly given in a passive manner, e.g. in the form of – both literally and metaphorically – standing by a friend during conflicts with a third party, followed by social grooming with the friend. Social grooming has been shown by other authors to reduce physiological symptoms of stress. In addition, external signs of relaxation indicate a decrease in psychological tension. Hence, psychological support enhances the animal's physical health (and ultimately increases its biological fitness), providing an indirect practical benefit.

* Since all larger species of farm animals are highly social ungulates, the demonstration and verification of friendships implies consequences for husbandry practice. Intensive husbandry conditions are characterised by high animal densities, resulting in increased social stress, and grouping of animals of similar ages, which interferes with or prevents the formation and maintenance of bonds between kin. As friendships develop preferentially between individuals of similar age, they can be accommodated with relatively little effort when deciding about regrouping. The study presented here provides explicit recommendations to interested stockpersons on how to expeditiously and efficiently identify existing friendships and on which aspects to take into account when regrouping established herds or introducing new members.

* The different aspects of the study and their complex and often interwoven interrelations are condensed into a 'Regelkreismodell'. This model facilitates the generation of precise hypotheses for future research. Further detailed investigation into a variety of questions raised by this study seems in many ways promising and rewarding.

* The successful demonstration and verification of the existence of friendship in ungulates requires an extension of the 'concept of friendship' beyond the order of primates and encourages more detailed research into the bonding behaviour of other social vertebrates (e.g. elephants, dolphins, carnivores and also parrots).

* This extension demands a reinterpretation of some behaviours which so far have been unsatisfactorily or controversially classified, such as social head or horn rubbing in sheep, which has been mentioned occasionally, but received very little attention in the literature. Due to its occurrence during aggressive interactions, some authors consider horn or head rubbing to be agonistic. Others suppose the preorbital gland to play a significant role in this type of interaction and interpret head or horn rubbing as a 'respectful gesture' (adopting the dominant sheep's individual scent).

The study presents the first description of cheek-to-cheek contact in sheep. These cheek contacts are unequivocally sociopositive in nature. Since they are frequently associated with head rubbing, a third interpretation of head rubbing behaviour is offered by classifying both behaviours within the context of social grooming s.l.. More detailed examinations of these behaviours will be conducted as part of a research project into the evolution of the bovidae.		  
  Address  
  Corporate Author Thesis Ph.D. thesis  
  Publisher University of Marburg Place of Publication Marburg Editor  
  Language German Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number refbase @ user @ Serial 824  
Permanent link to this record
 
 
Author Wasilewski, A. url  openurl
  Title “Freundschaft” bei Huftieren? – Soziopositive Beziehungen zwischen nicht-verwandten artgleichen Herdenmitgliedern Type Manuscript
  Year 2003 Publication Abbreviated Journal  
  Volume Issue Pages  
  Keywords  
  Abstract (up) http://www.staff.uni-marburg.de/~z-phylog/wisstaff/wasi-zus.htm

Zusammenfassung

* In der vorliegenden Arbeit werden Bindungen, wie sie beim Menschen als 'Freund-schaften' bezeichnet werden und im Laufe der letzen 30 Jahre auch für nicht-menschliche Primaten zunehmend anerkannt worden sind, bei Nicht-Primaten nachgewiesen und erstmals quantitativ analysiert.

* für die gewählte Fragestellung sind Untersuchungen an Huftieren besonders geeignet, denn Ungulaten können wie Primaten eine komplexe soziale Organisation besitzen und sind zugleich phylogenetisch weit von ihnen entfernt. Bislang allerdings legt die Forschung zum Sozialverhalten von Ungulaten allgemein, und v.a. die von domestizierten Huftieren, ungerechtfertigt starkes Gewicht auf die agonistischen (sozionegativen) Komponenten wie z.B. Konflikte und die daraus resultierenden Dominanzhierarchien; sie berücksichtigt soziopositive Verhaltensweisen kaum.

So haben die bisherigen Hinweise auf die Existenz von 'Huftierfreundschaften' vor-wiegend anekdotischen Charakter. In den selteneren Arbeiten, die explizit sozio-positive Beziehungen innerhalb der Herden untersuchen, vermischen sich freund-schaftliche mit verwandtschaftlichen und sexuell motivierten Bindungen.

* Die Untersuchungen der vorliegenden Arbeit wurden an je zwei Arten der beiden großen Huftierordnungen, nämlich Pferden und Eseln (Perissodactyla, Equidae) sowie Schafen und Rindern (Artiodactyla, Bovidae) durchgeführt. Es wurde ein vergleichender, individuenbasierter (und daher hochauflösender) Ansatz mit 'Langzeitcharakter' gewählt, der alle drei Ebenen der sozialen Organisation erfaßt: Assoziationen, Interaktionen und Muster der Bindungsstrukturen innerhalb sozialer Einheiten. Durch den systematischen, quantitativen, individuenbasierten und mit vier Tierarten relativ breit angelegten Ansatz kommt der vorliegenden Arbeit ein gewisser 'Pioniercharakter' zu, der v.a. im Bereich der Datenaufnahme- und -auswertungsmethoden ein mitunter beträchtliches Maß an Entwicklungsarbeit erforderte.

* Aus zwei Gründen wurde die Untersuchung an landwirtschaftlichen Nutztieren durchgeführt: Zum einen erleichtern die i.d.R. bekannten Verwandtschaftsbeziehungen eine Differenzierung zwischen 'Freundschaft' und Verwandtschaft. Zum anderen impliziert ein erfolgreicher Nachweis von 'Huftierfreundschaften' Konsequenzen für die Tierhaltungspraxis, denn ein soziales Umfeld, das den psychosozialen Bedürfnissen der Tiere Rechnung trägt, ist unabdingbare Voraussetzung für ihr Wohlbefinden (ethischer Tierschutz) und resultiert letztendlich in höherer Leistungsfähigkeit und damit ökonomischer Effizienz (anthropozentrischer Tierschutz).

Die Datenaufnahme im Freiland fand in England statt. Während die Rinder und Schafe unter kommerziellen Haltungsbedingungen lebten, konnten geeignete Pferde- und Eselherden nur in einem Horse Sanctuary (im weitesten Sinne vergleichbar mit einem Gnadenhof) gefunden werden.

* für die vorliegende Arbeit wurden von jeder der vier Tierarten, Rinder, Schafe, Esel und Pferde, zwei bis drei Herden mit je 11 bis 60 Mitgliedern (mittlere Herdengröße ca. 25) in zwei aufeinanderfolgenden Jahren (1996: 36 Wochen, 1997: 28 Wochen) untersucht. Die Rinderherde bestand aus vorwiegend subadulten, weiblichen Individuen; bei den übrigen drei Tierarten handelte es sich nahezu ausnahmslos um adulte Tiere. Die beiden Equidenarten lebten in gemischtgeschlechtlichen Herden, wobei alle männlichen Tiere kastriert waren (Wallache), während die Junggesellenherden der Schafe aus nicht kastrierten Tieren (Widdern) bestanden. In die vorgestellten Auswertungen gingen die Daten von 234 Tieren und ca. 1500 Untersuchungsstunden ein.

* Da selbst in der humanpsychologischen Freundschaftsforschung weder eine einheitliche Definition noch eine verbindliche Terminologie existiert, wurde zunächst eine allgemeingültige Definition des Freundschaftsbegriffs erarbeitet. Diese verzichtet bewußt auf funktionale Kriterien (sie beschränkt sich auf formale und inhaltliche) und enthält alle wesentlichen Charakteristika einschließlich solcher, die Freundschaften gegenüber anderen soziopositiven Beziehungen abgrenzen.





Freundschaft bezeichnet freiwillige und reziproke, nicht-sexuell motivierte, sozio-positive Bindungen zwischen nicht-verwandten Individuen. Sie ist primär dyadisch und besitzt für beide Beteiligten einen subjektiven Wert. Die Freund-schafts-beziehung ist durch positiven Affekt ('Sympathie') gekennzeichnet und äußert sich in einer beständigen interindividuellen Präferenz.

Diese Definition ist sowohl auf zwischen-menschliche als auch auf zwischen-tierliche und ggf. spezies-übergreifende Sozialbeziehungen anwendbar.

* Als Indikatorparameter für 'Freundschaften' wurden zum einen die räumliche Nähe (Nachbarschaftshäufigkeiten; Präferenzen reflektieren Assoziationen), zum anderen die Häufigkeiten verschiedener spontaner und experimentell induzierter soziopositiver Interaktionen herangezogen. Von den insgesamt vier erfaßten Interaktionen (soziale Fellpflege s.l., Körperkontakte beim Ruhen, Teilen von Futter und Verhaltensweisen des Dokumentierens s.l.) erwiesen sich aus unterschiedlichen Gründen lediglich Fellpflege und Futterteilen als geeignet.

* Während das spontane Verhalten bei allen Herden und in beiden Jahren erfaßt werden konnte, erlaubten die Haltungsbedingungen nur bei einigen Herden eine Ergänzung durch experimentelle Ansätze. Der Schwerpunkt der Arbeit liegt daher auf der Analyse des spontanen Verhaltens. Zur Datenaufnahme wurden verschiedene Sampling- und Recording-Methoden, i.d.R. in Kombination, verwandt (z.B. Scan Sampling für die Nachbarschaftsdaten, Ad libitum Sampling und Continuous Recording für die Interaktionsereignisse).

* Im Rahmen der Auswertung fand eine umfassende statistische Bearbeitung des Datenmaterials statt. Neben gängigeren uni- und bivariaten Verfahren (Binomial- und Chi-Quadrat-Anpassungstests, bivariate Korrelationen und Mantel-Tests) kamen v.a. multivariate Statistiken (Multidimensionale Skalierungen und hierarchische Cluster-analysen, partielle Korrelationen und multiple Mantel-Tests) zum Einsatz. Die Mantel-Tests (als Randomisierungsverfahren) waren aufgrund des dyadischen Charakters der Daten (Tier-Tier-Kombinationen), der nur in Form von Matrizen (d.h. nicht vollständig unabhängige Daten) erfaßt werden kann, zur Signifikanzprüfung notwendig. Darüber hinaus war die Entwicklung und Optimierung eines 'maßgeschneiderten' Auszählungsprogramms (NENESYS = NEarest NEighbour SYstematic Standardisation programme) erforderlich, die in interdisziplinärer Zusammenarbeit mit Informatikern und Mathematikwissenschaftlern stattfand.

* Im Ergebnisteil konnten Aussagen zu insgesamt sieben verschiedenen Aspekten von Huftierfreundschaften gemacht werden, die hauptsächlich aus Gründen der erforderlichen Prioritätensetzung unterschiedlich umfangreich und tiefgehend ausfielen:

1. Nachweis von Freundschaften bei Ungulaten

2. Quantifizierung der interindividueller Präferenzen

3. Situationsspezifität der Präferenzen

4. Dynamik und Dauer von Freundschaften

5. Asymmetrie innerhalb der Beziehungen

6. Freundschaften begünstigende Bedingungen

7. Funktionen von Tierfreundschaften



* Bei allen vier Tierarten zeigten sich sowohl bzgl. der räumlichen Nähe als auch im Hinblick auf die Partner bei soziopositiven Interaktionen deutliche interindividuelle ('persönliche') Präferenzen. In dem Bemühen um konservative und damit verläßliche Bewertungen wurden Nachbarpräferenzen allerdings erst dann als Assoziationen gewertet, wenn sie ein definiertes Beständigkeitsmaß überschritten. Da die Rahmenbedingungen der Untersuchung gewährleisteten, daß solche Assoziationen die Kriterien der Freundschafts-definition erfüllten, und andere Bindungsgrundlagen (Verwandtschaft und sexuelle Motivation = 'reproductive relationships') ausschlossen, ist der erstmals angestrebte generelle Nachweis von Freundschaften bei allen vier Arten von Huftieren als erfolgreich zu bewerten. Dieser Nachweis macht eine Ausweitung des Freundschafts-konzepts über die Primaten hinaus notwendig.

* Die Interaktionshäufigkeiten sind aufgrund ihres methodisch bedingten semi-quantitativen Charakters lediglich innerhalb der Herden vergleichbar.

Das Verwenden von Nachbarschaftshäufigkeiten als vollständig quantitativem Indikator bei allen zehn Herden ermöglicht hingegen einen unmittelbaren Vergleich zwischen den vier Tierarten, den Herden einer Art und den Individuen einer Herde. Aus Gründen des Umfangs beschränkt sich die Arbeit weitgehend auf den zwischenartlichen Vergleich.

Die Tierarten ließen sich – mit Ausnahme der Esel – im Hinblick auf die bei ihnen realisierten höchsten Assoziationsstärken, die maximalen Gruppengrößen und den Anteil gruppenzugehöriger Herdenmitglieder auf einem Wertegradienten anordnen. So nahmen die Kenngrößen der Tierarten in der Reihenfolge Rinder – Schafe – Pferde zu. über diese drei Arten hinweg bestand ein positiver Zusammenhang zwischen der Höhe der Assoziations-stärken, der Gruppengröße und dem Anteil gruppenzugehöriger Herdenmitglieder. Die Esel ließen sich nicht in dieses Schema einordnen, denn ihr Assoziationsgefüge war einerseits von dem geringsten Anteil gruppenzugehöriger Tiere und den kleinsten Gruppengrößen (ausschließlich Zweiergruppen) gekennzeichnet, andererseits zeichneten sich diese Zweiergruppen durch sehr hohe Bindungsstärken aus.

* Der Vergleich der interindividuellen Präferenzen in bis zu vier unterschiedlichen Situationen zeigte (neben gewissen individuellen Variationen) deutliche interspezifische Unterschiede. Diese waren mitunter zwischen den beiden Arten derselben Ordnung größer als zwischen Angehörigen verschiedener Ordnungen.

Bezüglich der Assoziationsstrukturen beim Grasen und Ruhen zeigten sich bei den vier untersuchten Arten zwei grundsätzliche Muster: Die Pferde- und Schafherden waren in beiden Aktivitätszuständen in distinkte, i.d.R. exklusive und autonome Gruppen strukturiert, und ihre Assoziationen stimmten in beiden Zuständen weitgehend überein (Aktivitätsunabhängigkeit). Im Gegensatz dazu besaßen die Esel und Rinder diffuse, unvollständige Assoziationsnetzwerke. Bei diesen Tierarten war nur ein weit geringerer Anteil der Assoziationen über beide Aktivitätszustände hinweg stabil.

Bei allen vier Tierarten konnten die Häufigkeiten sozialer Fellpflege s.l. (für Schafe gilt bislang, daß soziale Fellpflege bei ihnen nicht vorkommt, jedoch s.u.) mit den Nachbar-schafts-häufigkeiten beim Grasen und Ruhen verglichen werden; bei den beiden Equiden-arten kamen noch die Häufigkeiten des Futterteilens hinzu.

Während die Pferde ihre soziopositiven Interaktionen vollständig (Fellpflege) oder hauptsächlich (Futterteilen) auf Mitglieder ihrer eigenen Gruppe beschränkten, konnte bei Rindern nahezu keine übereinstimmung zwischen Präferenzen beim Grasen, beim Ruhen und bei der sozialen Fellpflege gefunden werden. Die Esel streuten ihre Präferenzen sehr deutlich, indem sie typischerweise zur Fellpflege Tiere aufsuchten, in deren Nähe sie sich sonst selten aufhielten. Beim Futterteilen zeigten sich zwei unterschiedliche Verhaltens-typen: Esel, die sowohl beim Grasen als auch beim Ruhen eng mit einem anderen Tier assoziiert waren, teilten mit diesem Partner auch besonders häufig, während die übrigen Esel sowohl mit ihren häufigsten Nachbarn als auch mit anderen Herdenmitgliedern teilten. Bei Schafen konnte wahrscheinlich gemacht werden, daß dem unidirektionalen Kopfreiben und dem hier erstmals beschriebenen reziproken Verweilen im Wangenkontakt zumindest die bindungsfürdernde und spannungsreduzierende Funktion der sozialen Fellpflege zukommen. Diese Verhaltensweisen fanden gehäuft, aber keines-wegs ausschließlich innerhalb der Assoziationsgruppen statt, die beim Grasen und Ruhen weitgehend übereinstimmten.

* Die vorliegende Arbeit enthält Hinweise darauf, daß möglicherweise verschiedene Interaktionsformen bzw. Assoziationen während bestimmter Aktivitätszustände zum Eingehen neuer Freundschaften, zum Festigen und Intensivieren bestehender Bindungen besonders geeignet sind und während der entsprechenden Phasen besonders häufig vorkommen. So scheint z.B. bei Pferden v.a. die soziale Fellpflege zur Initiation neuer Bindungen genutzt zu werden und gemeinsames Ruhen kürzlich eingegangene Beziehungen zu festigen.

Der Zeitrahmen der Untersuchung erlaubte es, bestehende Bindungen über maximal 18 Monate zu verfolgen. Die Bindungsdauern der Pferde und Schafe waren mit den Angaben anderer Autoren (für Herden mit einem sozialen Netzwerk aus Freundschaft und Verwandtschaft) vergleichbar, die der untersuchten Rinder fielen deutlich geringer aus, während sich die der Esel als ca. doppelt so lang wie der höchste vergleichbare Literaturwert erwiesen.

* Das Ausmaß der Asymmetrie innerhalb dyadischer Beziehungen wird in der vorliegenden Arbeit v.a. bei den unidirektionalen Fellpflegeverhaltensweisen der Boviden (Belecken der Rinder, Kopfreiben der Schafe) deutlich, die beide zudem entweder spontan oder nach Aufforderung stattfinden können.

* Bei der Suche nach Faktoren, die Freundschaften begünstigen, wurden einige statistisch abgesicherte Zusammenhänge zwischen Ähnlichkeiten bzgl. verschiedener individueller Eigenschaften und den Nachbarschaftshäufigkeiten gefunden. So erwies sich bei Rindern Gleichaltrigkeit als relevant, bei den Schafen der Besitz bzw. das Fehlen von Hörnern. Die in der Literatur wiederholt postulierte Präferenz bei Pferden für gleichfarbige (und ähnlich große) Freunde konnte nicht bestätigt werden.

Ob zusätzlich zum Ähnlichkeitsprinzip (“gleich und gleich gesellt sich gern”) auch das Komplementärprinzip (“Gegensätze ziehen sich an”) wirksam ist, läßt sich derzeit nicht entscheiden.

* Nach einer kritischen Beurteilung der verwendeten Methoden beschäftigt sich der anwendungsorientierte Teil der Diskussion zunächst mit dem Nutzen von Huftier-freundschaften. für einen (direkten) konkreten, praktischen Nutzen wurden kaum schlüssige Hinweise gefunden. Im Gegensatz dazu konnte die vorliegende Arbeit einen psychologischen Nutzen in Form von sozialer / emotionaler Unterstützung wahr-schein-lich machen:

Neben verschiedenen anekdotischen Hinweisen darauf, daß Situationen, die auf die Tiere verunsichernd wirken, das Eingehen bzw. Intensivieren von Freundschaften begünstigen können, ließ sich der Zusammenhang zwischen (annähernd) zeitgleichem Eintritt in eine neue Herde (unbekanntes soziales Umfeld) und beständigen Assoziationen (als ein Indikator für Freundschaft) bei Pferden und Schafen statistisch nachweisen. Insgesamt liegt der Schluß nahe, daß Huftierfreundschaften ein Gefühl von Sicherheit vermitteln. Die soziale / emotionale Unterstützung zwischen befreundeten Tieren wird dabei vorwiegend passiv gewährt, z.B. in Form von (sowohl wörtlichem wie metaphorischem) Beistand während Auseinandersetzungen des Freundes mit dritten und anschließender sozialer Fellpflege. Soziale Fellpflege mindert nachgewiesenermaßen physiologische Streßsymptome. Die in der vorliegenden Studie beobachteten äußerlichen Kennzeichen der Spannungs-Reduktion weisen zudem auf eine psychische Entspannung hin. Letztendlich wirkt sich die psychologische Unterstützung so auch auf das körperliche Wohlergehen (und ultimativ die biologische Fitness des betreffenden Tieres) aus und hat einen indirekten praktischer Nutzen.

* Alle größeren landwirtschaftlichen Nutztiere gehören den beiden hochgradig sozialen Huftierordnungen an. Der positive Nachweis von Freundschaften impliziert daher Konsequenzen für die Tierhaltungspraxis. Intensive Haltungsbedingungen sind u.a. durch hohe Tierdichten gekennzeichnet und verhindern i.d.R. das Eingehen bzw. Aufrechterhalten von Bindungen zwischen Verwandten, da Nutztiere üblicherweise in Gruppen ähnlich alter Tiere gehalten werden. Freundschaften werden v.a. zwischen Gleichaltrigen geknöpft und können bei Umgruppierungsentscheidungen mit relativ geringem Aufwand berücksichtigt werden. Die Arbeit gibt interessierten Tierhaltern konkrete Empfehlungen, wie sie bestehende Freundschaftsbindungen in ihren Herden mit geringem Zeit- und Arbeitsaufwand identifizieren können und welche Aspekte berücksichtigt werden sollten, wenn Teile bestehender Herden umgruppiert oder neue Herdenmitglieder integriert werden.

* Die verschiedenen Aspekte der Arbeit, die mitunter komplexen Wechselwirkungen untereinander sowie die Einflüsse der Haltungsbedingungen und die Konsequenzen für die Haltungs-praxis werden in einem 'Regelkreismodell' zusammengefaßt. Dieses Modell erlaubt u.a. das Aufstellen konkreter Hypothesen für weiterführende Fragestellungen. Ihnen nachzugehen, erscheint in vielerlei Hinsicht lohnend und erfolgversprechend.

* Der erfolgreiche Nachweis von Freundschaften bei Huftieren erfordert eine Ausweitung des Freundschaftskonzepts auch auf Nicht-Primaten und legt nahe, zukünftig auch andere soziale Wirbeltiere (z.B. Elephanten, Delphine, Reißtiere, aber auch Papageien) im Hinblick auf diesen Bindungstyp (eingehender) zu untersuchen.

* Diese Ausweitung des Konzepts ermöglicht eine Reinterpretation einiger bisher unbe-friedigend oder widersprüchlich klassifizierter Verhaltensweisen. So ist z.B. das bei Schafen gelegentlich erwähnte, ansonsten wenig beachtete, soziale Kopf- oder Hornreiben bislang nie in den Kontext der sozialen Fellpflege gestellt worden. Wegen seines Auftretens während Auseinandersetzungen interpretieren manche Autoren dieses Verhalten als ebenfalls agonistisch. Andere Autoren vermuten, daß die Voraugendrüse bei diesen Kontakten eine wichtige Rolle spielt und sehen darin eine 'respektanzeigende' Geste (Annahme des Individualgeruchs des dominanten Tieres).

Die vorliegende Arbeit beschreibt erstmalig für Schafe Verweilen im Wangenkontakt. Diese Wangenkontakte besitzen einen eindeutig soziopositiven Charakter. Da sie häufig in Zusammenhang mit unidirektionalem Kopfreiben auftreten, wird als dritte Inter-pretation des Kopfreibeverhaltens die Einordnung in den Freundschaftskontext (als soziale Fellpflege s.l.) vorgeschlagen. Vertiefende Studien dazu werden u.a. Gegenstand des anschließenden Forschungsprojekts zur Evolution der Boviden sein.		  
  Address  
  Corporate Author Thesis Doctoral 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  
  Area Expedition Conference  
  Notes Approved no  
  Call Number refbase @ user @ Serial 823  
Permanent link to this record
Select All    Deselect All << 1 2 3 4 5 6 7 8 9 10 >> [11–20]
List View
 | 
Citations
 | 
Details
   print
toggle visibility Cite Options
Home CQL Search  |  Library Search  |  Show Record  |  Extract Citations Help