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Articles 1 - 7 of 7

Full-Text Articles in Psychology

Farrowing Behaviour And Stillbirth In Two Environments: An Evaluation Of The Restraint-Stillbirth Hypothesis, D. Fraser, P. A. Phillips, B. K. Thompson Dec 1997

Farrowing Behaviour And Stillbirth In Two Environments: An Evaluation Of The Restraint-Stillbirth Hypothesis, D. Fraser, P. A. Phillips, B. K. Thompson

Reproductive Behavior Collection

A total of 59 farrowings were studied in either a conventional, narrow farrowing crate (0.43 m wide) or a much wider alternative design with sides spaced 1.2 m apart at the sow’s standing height but narrowing near the floor to limit the sow’s lying area. Using video recording, we monitored each “birth interval” (i.e. the period between two successive births) and noted the interval’s length, the sow’s posture and postural changes during the interval, and whether the interval ended with a live-born or stillborn piglet. The wide and conventional crates did not differ significantly in median interval between piglets (15.9 …


Weapon Size Versus Body Size As A Predictor Of Winning In Fights Between Shore Crabs, Carcinus Maenas (L.), Lynne U. Sneddon, Felicity A. Huntingford, Alan C. Taylor Oct 1997

Weapon Size Versus Body Size As A Predictor Of Winning In Fights Between Shore Crabs, Carcinus Maenas (L.), Lynne U. Sneddon, Felicity A. Huntingford, Alan C. Taylor

Veterinary Science and Medicine Collection

Relative body size (carapace width) and weapon size (chela length) were used as indicators of resource holding potential (RHP) in the agonistic behaviour of male shore crabs, Carcinus maenas (L.). Weapon size was found to be a more reliable predictor of the outcome of pairwise fights than body size. Crabs with longer chelae than their opponents were more likely to win fights than crabs with relatively larger bodies. Body size had less influence on the outcome of fights. Relative body and weapon size did not influence initiation of contests but did affect the likelihood of winning; however, this was significant …


Life In Captivity: Its Lack Of Opportunities For Variable Behaviour, Françoise Wemelsfelder Aug 1997

Life In Captivity: Its Lack Of Opportunities For Variable Behaviour, Françoise Wemelsfelder

Zoos and Aquariums Collection

No abstract provided.


Vocalizations By Isolated Piglets: A Reliable Indicator Of Piglet Need Directed Towards The Sow, Daniel M. Weary, Stephen Ross, David Fraser Jul 1997

Vocalizations By Isolated Piglets: A Reliable Indicator Of Piglet Need Directed Towards The Sow, Daniel M. Weary, Stephen Ross, David Fraser

Communication Skills Collection

When suckling piglets are isolated from the sow and litter-mates they vocalize a great deal. Sows also call when isolated from their piglets. In one experiment, we found that isolated piglets doubled their call rate in response to playback of sow calls, indicating that piglets are directing calls towards the sow. In a second experiment, we found that variation in the piglet isolation calls related to aspects of the piglet's condition: piglets isolated for 13 min in an enclosure kept at approximately 14°C called more, used higher frequency calls and longer calls, than litter-mates isolated in an enclosure kept at …


The Scientific Validity Of Subjective Concepts In Models Of Animal Welfare, Françoise Wemelsfelder May 1997

The Scientific Validity Of Subjective Concepts In Models Of Animal Welfare, Françoise Wemelsfelder

Animal Welfare Collection

This paper takes a closer look at the subjectivity/objectivity relationship, as it plays a role in the science of animal welfare. It argues that subjective, experiential states in animals such as well-being and suffering are, contrary to what is often assumed, open to empirical observation and scientific assessment. The presumably purely private, inaccessible nature of such states is not an inherent property of these states, but derives from their misguided conception as ‘causal objects’ in mechanistic models of behaviour. This inevitably endows subjective experience with a ‘hidden’ status. However, subjective experience should be approached on its own conceptual grounds, i.e. …


Development Of Piagetian Object Permanence In A Grey Parrot (Psittacus Erithacus), Irene M. Pepperberg, Mark R. Willner, Lauren B. Gravitz Mar 1997

Development Of Piagetian Object Permanence In A Grey Parrot (Psittacus Erithacus), Irene M. Pepperberg, Mark R. Willner, Lauren B. Gravitz

Sentience Collection

The authors evaluated the ontogenetic performance of a grey parrot (Psittacus erithacus) on object permanence tasks designed for human infants. Testing began when the bird was 8 weeks old, prior to fledging and weaning. Because adult grey parrots understand complex invisible displacements (I. M. Pepperberg & F. A. Kozak, 1986), the authors continued weekly testing until the current subject completed all of I. C. Uzgiris and J. Hunt's (1975) Scale 1 tasks. Stage 6 object permanence with respect to these tasks emerged at 22 weeks, after the bird had fledged but before it was completely weaned. Although the parrot progressed …


Language-Naive Chimpanzees (Pan Troglodytes) Judge Relations Between Relations In A Conceptual Matching-To-Sample Task, Roger K.R. Thompson, David L. Oden, Sarah T. Boysen Jan 1997

Language-Naive Chimpanzees (Pan Troglodytes) Judge Relations Between Relations In A Conceptual Matching-To-Sample Task, Roger K.R. Thompson, David L. Oden, Sarah T. Boysen

Sentience Collection

Three chimpanzees with a history of conditional and numeric token training spontaneously matched relations between relations under conditions of nondifferential reinforcement. Heretofore, this conceptual ability was demonstrated only in language-trained chimpanzees. The performance levels of the language-naive animals in this study, however, were equivalent to those of a 4th animal—Sarah—whose history included language training and analogical problem solving. There was no evidence that associative factors mediated successful performance in any of the animals. Prior claims of a profound disparity between language-trained and language-naive chimpanzees apparently can be attributed to prior experience with arbitrary tokens consistently associated with abstract relations and …