| Home | [1–10] << 11 12 13 14 15 16 17 18 19 20 >> [21–30] |
|
| Records | |||||
|---|---|---|---|---|---|
| Author | Gentner, T.Q.; Fenn, K.M.; Margoliash, D.; Nusbaum, H.C. | ||||
| Title | Recursive syntactic pattern learning by songbirds | Type  |
Journal Article | ||
| Year | 2006 | Publication | Nature | Abbreviated Journal | Nature |
| Volume | 440 | Issue | 7088 | Pages | 1204-1207 |
| Keywords | Acoustic Stimulation; *Animal Communication; Animals; Auditory Perception/*physiology; Humans; *Language; Learning/*physiology; Linguistics; Models, Neurological; Semantics; Starlings/*physiology; Stochastic Processes | ||||
| Abstract | Humans regularly produce new utterances that are understood by other members of the same language community. Linguistic theories account for this ability through the use of syntactic rules (or generative grammars) that describe the acceptable structure of utterances. The recursive, hierarchical embedding of language units (for example, words or phrases within shorter sentences) that is part of the ability to construct new utterances minimally requires a 'context-free' grammar that is more complex than the 'finite-state' grammars thought sufficient to specify the structure of all non-human communication signals. Recent hypotheses make the central claim that the capacity for syntactic recursion forms the computational core of a uniquely human language faculty. Here we show that European starlings (Sturnus vulgaris) accurately recognize acoustic patterns defined by a recursive, self-embedding, context-free grammar. They are also able to classify new patterns defined by the grammar and reliably exclude agrammatical patterns. Thus, the capacity to classify sequences from recursive, centre-embedded grammars is not uniquely human. This finding opens a new range of complex syntactic processing mechanisms to physiological investigation. | ||||
| Address | Department of Organismal Biology and Anatomy, University of Chicago, Chicago, Illinois 60637, USA. tgentner@ucsd.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 | 1476-4687 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | PMID:16641998 | Approved | no | ||
| Call Number | refbase @ user @ | Serial | 353 | ||
| Permanent link to this record | |||||
| Author | Judge, P.G.; Mullen, S.H. | ||||
| Title | Quadratic postconflict affiliation among bystanders in a hamadryas baboon group | Type |
Journal Article | ||
| Year | 2005 | Publication | Animal Behaviour. | Abbreviated Journal | Anim. Behav. |
| Volume | 69 | Issue | 6 | Pages | 1345-1355 |
| Keywords | |||||
| Abstract | The tendency in primate groups for two opponents to affiliate shortly after a fight has been described as dyadic reconciliation. The response has been shown to restore disrupted relationships and curtail ongoing aggression. Rates of self-directed behaviour (e.g. scratching) are positively correlated with anxiety in primates and the rates decline after reconciliation, indicating that the response also functions to reduce postconflict tension. Third parties not involved in an aggressive interaction are also likely to affiliate with one of the combatants subsequent to a fight. Such `triadic' interactions may also promote conflict resolution when, for instance, the relatives of a victim affiliate with their relative's aggressor. Because aggression in a group influences a bystander's behaviour with combatants, we hypothesized that aggression between two animals would also influence a bystander's behaviour with other bystanders. Such `quadratic' postconflict interactions might also function to reduce postconflict tension or occur in patterns among kin subgroups to resolve conflict. We tested for quadratic interactions in an 18-member group of captive hamadryas baboons, Papio hamadryas hamadryas. Immediately following a fight, an uninvolved bystander was randomly selected for observation and its affiliative interactions with other bystanders and its displacement activities were recorded for 3 min. Rates of behaviour during these postconflict periods were compared to rates during 3-min baseline periods not preceded by aggression. Bystanders engaged in quadratic interactions by increasing affiliation with other bystanders following aggression. Bystanders directed affiliation to nonkin bystanders that were their preferred social partners. Displacement activities of bystanders were significantly higher during postconflict intervals compared to baseline intervals, and bystander displacement activity levels before affiliative contact with other bystanders were significantly higher than after contact. Apparently, bystanders become tense or anxious after witnessing aggression and affiliate with preferred partners to reduce the arousal. | ||||
| 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 | 402 | ||
| Permanent link to this record | |||||
| Author | Clutton-Brock, T.H.; Russell, A.F.; Sharpe, L.L.; Brotherton, P.N.; McIlrath, G.M.; White, S.; Cameron, E.Z. | ||||
| Title | Effects of helpers on juvenile development and survival in meerkats | Type |
Journal Article | ||
| Year | 2001 | Publication | Science (New York, N.Y.) | Abbreviated Journal | Science |
| Volume | 293 | Issue | 5539 | Pages | 2446-2449 |
| Keywords | Animals; Breeding; Carnivora/growth & development/*physiology; *Cooperative Behavior; Feeding Behavior; Female; Male; Survival Rate; *Weight Gain | ||||
| Abstract | Although breeding success is known to increase with group size in several cooperative mammals, the mechanisms underlying these relationships are uncertain. We show that in wild groups of cooperative meerkats, Suricata suricatta, reductions in the ratio of helpers to pups depress the daily weight gain and growth of pups and the daily weight gain of helpers. Increases in the daily weight gain of pups are associated with heavier weights at independence and at 1 year of age, as well as with improved foraging success as juveniles and higher survival rates through the first year of life. These results suggest that the effects of helpers on the fitness of pups extend beyond weaning and that helpers may gain direct as well as indirect benefits by feeding pups. | ||||
| Address | Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK. thcb@hermes.cam.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 | 0036-8075 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | PMID:11577235 | Approved | no | ||
| Call Number | refbase @ user @ | Serial | 414 | ||
| Permanent link to this record | |||||
| Author | VanDierendonck, M.C.; de Vries, H.; Schilder, M.B.H. | ||||
| Title | An Analysis of Dominance, Its Behavioural Parameters and Possible Determinants in a Herd of Icelandic orses in Captivity | Type |
Journal Article | ||
| Year | 1995 | Publication | Netherlands Journal of Zoology | Abbreviated Journal | Netherl. J. Zool. |
| Volume | 45 | Issue | 3-4 | Pages | 362-385 |
| Keywords | Dominance; rank order; horses; Icelandic horses. | ||||
| Abstract | Th e applicability of the concept of dominance was investigated in a captive herd of  Icelandic horses and  ponies of diff erent breeds. Eight out of  behaviours possibly related to dominance occurred frequently enough to be investigated in detail. For these eight agonistic behaviours the coverage, the unidirectionality in the exchange, and the degree of transitivity (Landau`s linearity index) were calculated. Four off ensive behaviours, together with avoidance, were suitable for further analysis with regard to dominance. Th e patterns of asymmetries with which these behaviours were exchanged were suffi ciently similar as to justify the application of the dominance concept and to construct a (nearly) linear dominance hierarchy. Th e rank order of the castrated stallions was completely linear, the hierarchy of the mares was almost completely linear. Th e results suggest that off ensive and defensive aggressive behaviours should be treated separately and that the concept of dominance is applicable. However, ritualized formal dominance signals between adult horses appear to be (almost) absent. Th e rank positions of the individuals were correlated with age and residency in the herd but not with height. Middle ranking horses tended to be more frequently in the close vicinity of another horse than high ranking or low ranking horses. Over and above this correlation at the individual level, it was found that pairs of horses close in rank to each other were more often also spatially close to each other. Being in oestrus did not infl uence the dominance relationships between mares. For castrated stallions the rank positions were correlated with the age at which they were castrated. Th is suggests that in male horses experience prior to neutering infl uences the behaviour afterwards. |
||||
| Address | |||||
| 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 | ISBN | Medium | |||
| Area | Expedition | Conference | |||
| Notes | Approved | no | |||
| Call Number | refbase @ user @ | Serial | 440 | ||
| Permanent link to this record | |||||
| Author | Gammell, M.P.; de Vries, H.; Jennings, D.J.; Carlin, C.M.; Hayden, T.J. | ||||
| Title | David's score: a more appropriate dominance ranking method than Clutton-Brock et al.'s index | Type |
Journal Article | ||
| Year | 2003 | Publication | Animal Behaviour. | Abbreviated Journal | Anim. Behav. |
| Volume | 66 | Issue | 3 | Pages | 601-605 |
| Keywords | |||||
| Abstract | |||||
| 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 | 453 | ||
| Permanent link to this record | |||||
| Author | de Vries, H.; Stevens, J.M.G.; Vervaecke, H. | ||||
| Title | Measuring and testing the steepness of dominance hierarchies | Type |
Journal Article | ||
| Year | 2006 | Publication | Animal Behaviour. | Abbreviated Journal | Anim. Behav. |
| Volume | 71 | Issue | 3 | Pages | 585-592 |
| Keywords | |||||
| Abstract | In the analysis of social dominance in groups of animals, linearity has been used by many researchers as the main structural characteristic of a dominance hierarchy. In this paper we propose, alongside linearity, a quantitative measure for another property of a dominance hierarchy, namely its steepness. Steepness of a hierarchy is defined here as the absolute slope of the straight line fitted to the normalized David's scores (calculated on the basis of a dyadic dominance index corrected for chance) plotted against the subjects' ranks. This correction for chance is an improvement of an earlier proposal by de Vries (appendix 2 in de Vries, Animal Behaviour, 1998, 55, 827-843). In addition, we present a randomization procedure for determining the statistical significance of a hierarchy's steepness, which can be used to test the observed steepness against the steepness expected under the null hypothesis of random win chances for all pairs of individuals. Whereas linearity depends on the number of established binary dominance relationships and the degree of transitivity in these relationships, steepness measures the degree to which individuals differ from each other in winning dominance encounters. Linearity and steepness are complementary measures to characterize a dominance hierarchy. | ||||
| 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 | 454 | ||
| Permanent link to this record | |||||
| Author | Poisbleau, M.; Fritz, H.; Valeix, M.; Perroi, P.-Y.; Dalloyau, S.; Lambrechts, M.M. | ||||
| Title | Social dominance correlates and family status in wintering dark-bellied brent geese, Branta bernicla bernicla | Type |
Journal Article | ||
| Year | 2006 | Publication | Animal Behaviour. | Abbreviated Journal | Anim. Behav. |
| Volume | 71 | Issue | 6 | Pages | 1351-1358 |
| Keywords | |||||
| Abstract | In many gregarious species, including ducks and geese, being dominant provides more benefits than costs, because dominants have better access to resources essential for survival or reproduction. In geese, being in better body condition during migration towards the breeding grounds positively influences reproductive success. However, underlying proximate mechanisms linking prebreeding body condition on the wintering grounds to breeding success remain poorly understood. We investigated social dominance correlates and family status, in three consecutive winters, in a free-ranging, migrating, dark-bellied brent goose population. Families with juveniles dominated pairs, and pairs dominated singletons. Dominance rank did not increase with the number of juveniles per family. Males were dominant over females. Social dominance and reproductive status for a given winter were significantly correlated with body mass, body size and body condition during the previous winter, suggesting that body condition in winter also affects subsequent breeding success and hence also dominance. Levels of testosterone and triiodothyronine were not correlated with immediate or later dominance or reproductive status. We discuss the role of family status as a signal of social status in determining reproductive strategies. | ||||
| 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 | 0003-3472 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | no | |||
| Call Number | Equine Behaviour @ team @ | Serial | 4690 | ||
| Permanent link to this record | |||||
| Author | Poisbleau, M.; Jenouvrier, S.; Fritz, H. | ||||
| Title | Assessing the reliability of dominance scores for assigning individual ranks in a hierarchy | Type |
Journal Article | ||
| Year | 2006 | Publication | Animal Behaviour. | Abbreviated Journal | Anim. Behav. |
| Volume | 72 | Issue | 4 | Pages | 835-842 |
| Keywords | |||||
| Abstract | The dominance score (number of wins divided by the total number of interactions) is the most widely used procedure in field studies to rank individuals. Its reliability depends on the number of interactions on which it is calculated. However, most authors use it without any estimate of the associated error. We describe the precision associated with a dominance score estimate as a function of the number of interactions on which it is based, and hence provide a tool to plan field protocols and effort. The precision error decreases according to a power function with increasing number of interactions, but with more precision for extreme scores for any given number of interactions. We discuss the fact that the minimum number of interactions should be based on the precision associated with the 50% score, the least precise of all scores. We also emphasize the trade-off between recording effort and precision of the estimator, and give an example of our choice of 26 interactions for fieldwork on ducks and geese. When comparing individual ranks based on dominance scores with ranks given by the dominance matrix, we found a good correlation, with more mismatches around the middle of the hierarchy. This was consistent with the precision calculated with our model. We conclude that dominance score is a reliable tool, but conclusions must take into account the number of interactions on which the calculations are done. We also discuss the importance of initial assumptions and sources of bias in field studies. | ||||
| 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 | 456 | ||
| Permanent link to this record | |||||
| Author | de VRIES, H.A.N. | ||||
| Title | Finding a dominance order most consistent with a linear hierarchy: a new procedure and review | Type |
Journal Article | ||
| Year | 1998 | Publication | Animal Behaviour. | Abbreviated Journal | Anim. Behav. |
| Volume | 55 | Issue | 4 | Pages | 827-843 |
| Keywords | |||||
| Abstract | A procedure for ordering a set of individuals into a linear or near-linear dominance hierarchy is presented. Two criteria are used in a prioritized way in reorganizing the dominance matrix to find an order that is most consistent with a linear hierarchy: first, minimization of the numbers of inconsistencies and, second, minimization of the total strength of the inconsistencies. The linear ordering procedure, which involves an iterative algorithm based on a generalized swapping rule, is feasible for matrices of up to 80 individuals. The procedure can be applied to any dominance matrix, since it does not make any assumptions about the form of the probabilities of winning and losing. The only assumption is the existence of a linear or near-linear hierarchy which can be verified by means of a linearity test. A review of existing ranking methods is presented and these are compared with the proposed method. | ||||
| 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 | 457 | ||
| Permanent link to this record | |||||
| Author | Klingel, H. | ||||
| Title | Das Verhalten der Pferde (Equidae) | Type |
Journal Article | ||
| Year | Publication | Handbook of Zoology | Abbreviated Journal | Handb. o. Zool. | |
| Volume | 8 | Issue | 10 | Pages | 1-68 |
| Keywords | |||||
| Abstract | |||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Walter De Gruyter | Place of Publication | Berlin/Newyork | Editor | |
| Language | German English | 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 | 473 | ||
| Permanent link to this record | |||||