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	Author	Bergstrom,C. T.; Lachmann, M.
	Title	Signalling among relatives. I. Is costly signalling too costly?			Type	Journal Article
	Year	1997	Publication	Proceedings of the National Academy of Sciences of the United States of America	Abbreviated Journal	Proc. Natl. Acad. Sci. U.S.A.
	Volume	352(1353)	Issue		Pages	609-617
	Keywords	Signalling
	Abstract	ahavi's handicap principle,originally proposed as an explanation for sexual selection ofelaborate male traits, suggests that a sufficient cost to dishonest signals can outweigh the rewards of deception and allow individuals to communicate honestly. Maynard Smith (1991) and Johnstone and Grafen (1992) introduce the Sir Philip Sidney game in order to extend the handicap principle to interactions among related individuals, and to demonstrate that stable costly signalling systems can exist among relatives. In this paper we demonstrate that despite the benefits associated with honest information transfer, the costs incurred in a stable costly signalling system may leave all participants worse off than they would be in a system with no signalling at all. In both the discrete and continuous forms of the Sir Philip Sidney game, there exist conditions under which costly signalling among relatives, while stable, is so costly that it is disadvantageous compared with no signalling at all. We determine the factors which dictate signal cost and signal benefit in a generalized version of this game, and explain how signal cost can exceed signal value. Such results raise concerns about theevolutionary pathways which could have led to the existence of signalling equilibria in nature. The paper stresses the importance of comparing signalling equilibria with other possible strategies, beforedrawing conclusions regarding the optimality of signalling.
	Address
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	Publisher		Place of Publication		Editor
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	Notes				Approved	no
	Call Number	refbase @ user @			Serial	559
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	Author	Judge, P.G.; De Waa,l F.B.M.
	Title	Rhesus monkey behaviour under diverse population densities: coping with long-term crowding			Type	Journal Article
	Year	1997	Publication	Animal Behaviour.	Abbreviated Journal	Anim. Behav.
	Volume	54	Issue	3	Pages	643-662
	Keywords
	Abstract	A popular view is that high population density promotes behavioural pathology, particularly increased aggression. In contrast, according to a coping model, some primates have behavioural mechanisms (e.g. formal displays, reconciliation and grooming) that regulate social tensions and control the negative consequences of crowding. Seven captive rhesus monkey groups, Macaca mulattawere observed over a wide range of population densities where high-density groups were over 2000 times more crowded than low-density free-ranging groups. As density increased, male rhesus monkeys increased grooming and huddling but did not increase rates of aggression. Females increased all categories of behaviour examined (heavy aggression, mild aggression, formal bared-teeth displays, grooming and huddling), but the increases were not distributed uniformly to all classes of partners. Females increased only grooming, huddling and appeasement displays to males, increased only aggression and huddling with kin and increased all categories of behaviour to non-kin adult females. There were no differences in the percentage of aggressive conflicts reconciled across density conditions. Increased density had different effects on particular relationships. Relationships between females and males were characterized by a coping pattern in which animals modified their behaviour in ways that may decrease aggression under crowded conditions. Female relationships with kin and non-kin were characterized by increases in both aggression and friendly interactions as density increased. The different patterns of response to higher density may reflect different strategies depending on the strength and stability of relationships and the potential consequences if certain relationships are disrupted.1997The Association for the Study of Animal Behaviour
	Address	Yerkes Regional Primate Research Center and Department of Psychology, Emory University
	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	0003-3472	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:9299049			Approved	no
	Call Number	refbase @ user @			Serial	199
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	Author	Bugnyar T; Huber L
	Title	Push or pull: an experimental study on imitation in marmosets			Type	Journal Article
	Year	1997	Publication	Animal Behaviour.	Abbreviated Journal	Anim. Behav.
	Volume	54	Issue		Pages	817
	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	Equine Behaviour @ team @			Serial	2984
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	Author	Szenci, O.; Palme, R.; Taverne, M.A.; Varga, J.; Meersma, N.; Wissink, E.
	Title	Evaluation of false ultrasonographic pregnancy diagnoses in sows by measuring the concentration of unconjugated estrogens in feces			Type	Journal Article
	Year	1997	Publication	Theriogenology	Abbreviated Journal	Theriogenology
	Volume	48	Issue	5	Pages	873-882
	Keywords
	Abstract	On Days 26, 28, and 30 after AI, ultrasonographic pregnancy diagnoses were performed on 207 gilts and sows by using a 3.5 MHz linear-array transducer. Fecal samples were taken from the rectum after each ultrasonographic examination, and the concentrations of unconjugated estrogens in selected samples (n = 73) were measured by RIA. Fecal unconjugated estrogen concentration of 11.7 ng/g feces or higher was indicative of pregnancy. The overall sensitivity and specificity of the ultrasonographic test was 99% for farrowing sows and 73.1% for nonfarrowing sows. With one exception, sows with a false negative diagnosis by ultrasonography on Day 26 were correctly diagnosed pregnant by elevated fecal unconjugated estrogens or repeated ultrasonographic examinations on Days 28 or 30. Return to estrus around the sampling period may cause false positive results in the unconjugated estrogen assay, while early embryonic mortality can result in false positive diagnoses in both the ultrasonographic test and estrogen assay. Although there was a positive correlation between the concentrations of unconjugated estrogens in the feces and litter size at farrowing in the selected sows, it seems very unlikely that fecal estrogens can provide an accurate tool for predicting litter size.
	Address	University of Veterinary Science, Department of Obstetrics and Reproduction H-1400 Budapest, P.O. Box 2, Hungary
	Corporate Author				Thesis
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	Language	English	Summary Language		Original Title
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	Series Volume		Series Issue		Edition
	ISSN	0093-691X	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:16728179			Approved	no
	Call Number	Equine Behaviour @ team @			Serial	4077
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	Author	Pennisi, E.
	Title	Schizophrenia clues from monkeys			Type
	Year	1997	Publication	Science (New York, N.Y.)	Abbreviated Journal	Science
	Volume	277	Issue	5328	Pages	900
	Keywords	Animals; Antipsychotic Agents/pharmacology; Behavior, Animal/drug effects; Cercopithecus aethiops; Clozapine/pharmacology; Cognition/drug effects; Disease Models, Animal; Dopamine/metabolism; Excitatory Amino Acid Antagonists/pharmacology; Memory/drug effects; Phencyclidine/pharmacology; Prefrontal Cortex/metabolism; Schizophrenia/chemically induced/drug therapy/metabolism; Schizophrenic Psychology
	Abstract
	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	0036-8075	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:9281070			Approved	no
	Call Number	Equine Behaviour @ team @			Serial	2844
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	Author	Livoreil, B.; Giraldeau, L.
	Title	Patch departure decisions by spice finches foraging singly or in groups			Type	Journal Article
	Year	1997	Publication	Animal Behaviour.	Abbreviated Journal	Anim. Behav.
	Volume	54	Issue	4	Pages	967-977
	Keywords
	Abstract	The marginal value theorem predicts that when resources are clumped in space, a forager can maximize its rate of intake by deciding to leave a patch when its current feeding rate falls below the average for the habitat. A group version of the model predicts that when rate-maximizing group members share a patch, they should leave sooner, and each with less gain, than single animals exploiting the same patch. We tested these predictions in the laboratory by measuring patch departure decisions of spice finches, Lonchura punctulataexploiting food patches alone or in groups of three under two habitats that require different travel times. As predicted, group members left the patch sooner and with fewer seeds than single foragers. Unlike the model's assumptions, however, birds did not share the patch equally, and their exploitation curves could not be simply derived from those of single foragers. Grouping decreased the effect of travel time on patch exploitation. Moreover, within each group the bird expected to leave first delayed its departure although it collected fewer seeds than the others. This delayed departure could aim to maintain group membership. We noted an increased variability in seed number collected by group members compared with single foragers, which could be a cost of group foraging.Copyright 1997 The Association for the Study of Animal Behaviour1997The Association for the Study of Animal Behaviour
	Address	Department of Biology, Concordia University
	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	0003-3472	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:9344448			Approved	no
	Call Number				Serial	2138
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	Author	Reeve, H. Kern
	Title	Evolutionarily stable communication between kin: a general model			Type	Journal Article
	Year	1997	Publication	Proceedings of the Royal Society B: Biological Sciences	Abbreviated Journal	Proc. Roy. Soc. Lond. B Biol. Sci.
	Volume	264	Issue	(1384)	Pages	1037-1040.
	Keywords	Signalling Systems
	Abstract	At present, the most general evolutionary theory of honest communication is Grafen's model of Zahavi's 'handicap' signalling system, in which honesty of signals about the signaller's quality (e.g. mate suitability or fighting ability) is maintained by the differentially high cost of signals to signallers having lower quality. The latter model is here further generalized to include any communication between signallers and receivers that are genetically related (e.g. parents and begging offspring, cooperative or competing siblings). Signalling systems involving relatives are shown to be evolutionarily stable, despite a potential pay-off for false signalling, if the Zahavian assumption of differential signal costs holds and there are diminishing reproductive returns to the signaller as the receiver's assessed value of its attribute increases, or if, regardless of whether the Zahavian assumption holds, signallers with high values of the attribute benefit more from a given receiver assessment than signallers with low values (e.g. begging chicks that are hungrier benefit more from being fed). In stable systems of signalling among kin, it is also shown to be generally true that (i) levels of signalling and thus observed signal costs will decline as relatedness increases or as the receiver's reproductive penalty for erroneous assessment increases, and (ii) receivers will consistently, altruistically overestimate the true value of the signalled attribute.
	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	557
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	Author	Povinelli DJ; Gallup GG; Eddy TJ; Bierschwale DT; Engstrom MC
	Title	Chimpanzees recognize themselves in mirrors			Type	Journal Article
	Year	1997	Publication	Animal Behaviour.	Abbreviated Journal	Anim. Behav.
	Volume	53	Issue		Pages	1083
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	Abstract
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
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	Notes				Approved	no
	Call Number	Equine Behaviour @ team @			Serial	3029
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	Author	Bateson, M.; Kacelnik, A.
	Title	Starlings' preferences for predictable and unpredictable delays to food			Type	Journal Article
	Year	1997	Publication	Animal Behaviour.	Abbreviated Journal	Anim. Behav.
	Volume	53	Issue	6	Pages	1129-1142
	Keywords
	Abstract	Risk-sensitive foraging theory is based on the premise that unpredictable runs of good or bad luck can cause a variable food source to differ in fitness value from a fixed food source yielding the same average rate of gain but no unpredictability. Thus, risk-sensitive predictions are dependent on the food intake from variable sources being not only variable but also unpredictable or `risky' in outcome. This study tested whether unpredictability is a component of the value that foraging starlings,Sturnus vulgarisattribute to food sources that are variable in the delay to obtain food. Two groups of birds chose between a fixed and a variable delay option; the variable option was unpredictable in the risky group and predictable in the risk-free group in the overall rate of intake it yielded. In both groups the fixed option was adjusted by titration to quantify the magnitude of preference for predictable and unpredictable variance. On negative energy budgets both groups were significantly risk-prone, with the risky group being significantly more risk-prone than the risk-free group. Switching the birds to positive budgets by doubling the size of each food reward had no significant effect on preference, and similar trends to those found with negative budgets were observed. These results are not readily explained by risk-sensitive foraging theory, but may be explained by the algorithm used by the birds to attribute value to average expected rewards.
	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				Serial	2108
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	Author	Chalmeau, R.; Visalberghi, E.; Gallo, A.
	Title	Capuchin monkeys,Cebus apellafail to understand a cooperative task			Type	Journal Article
	Year	1997	Publication	Animal Behaviour.	Abbreviated Journal	Anim. Behav.
	Volume	54	Issue	5	Pages	1215-1225
	Keywords
	Abstract	We investigated whether capuchin monkeys cooperate to solve a task and to what extent they take into account the behaviour of another individual when cooperating. Two groups of capuchin monkeys (N=5 and 6) were tested in a task whose solution required simultaneous pulling of two handles which were too far from one another to be pulled by one monkey. Before carrying out the cooperation study, individual monkeys were trained to pull one handle (training phase 1) and to pull two handles simultaneously (training phase 2) for a food reward. Nine subjects were successful in training phase 1, and five in training phase 2. In the cooperation study seven subjects were successful, that is, pulled one handle while a companion pulled the other. Further analyses revealed that capuchins did not increase their pulling actions when a partner was close to or at the other handle, that is, when cooperation might occur. These data suggest that capuchin monkeys acted together at the task and got the reward without understanding the role of the partner and without taking its behaviour into consideration. Social tolerance, as well as their tendency to explore and their manual dexterity, were the major factors accounting for the capuchins' 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
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number	refbase @ user @			Serial	571
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