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Author Agrillo, C.; Dadda, M.; Bisazza, A.
Title Quantity discrimination in female mosquitofish Type Journal Article
Year 2007 Publication Animal cognition Abbreviated Journal Anim. Cogn.
Volume 10 Issue 1 Pages 63-70
Keywords Animals; Cognition; *Cyprinodontiformes; *Discrimination Learning; Female; Male; Mathematics; *Pattern Recognition, Visual
Abstract The ability in animals to count and represent different numbers of objects has received a great deal of attention in the past few decades. Cumulative evidence from comparative studies on number discriminations report obvious analogies among human babies, non-human primates and birds and are consistent with the hypothesis of two distinct and widespread mechanisms, one for counting small numbers (<4) precisely, and one for quantifying large numbers approximately. We investigated the ability to discriminate among different numerosities, in a distantly related species, the mosquitofish, by using the spontaneous choice of a gravid female to join large groups of females as protection from a sexually harassing male. In one experiment, we found that females were able to discriminate between two shoals with a 1:2 numerosity ratio (2 vs. 4, 4 vs. 8 and 8 vs. 16 fish) but failed to discriminate a 2:3 ratio (8 vs. 12 fish). In the second experiment, we studied the ability to discriminate between shoals that differed by one element; females were able to select the larger shoal when the paired numbers were 2 vs. 3 or 3 vs. 4 but not 4 vs. 5 or 5 vs. 6. Our study indicates that numerical abilities in fish are comparable with those of other non-verbal creatures studied; results are in agreement with the hypothesis of the existence of two distinct systems for quantity discrimination in vertebrates.
Address Department of General Psychology, University of Padova, via Venezia 8, 35131, Padova, Italy. christian.agrillo@unipd.it
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:16868736 Approved no
Call Number refbase @ user @ Serial 339
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Author Earley, R.L.; Dugatkin, L.A.
Title Eavesdropping on visual cues in green swordtail (Xiphophorus helleri) fights: a case for networking Type Journal Article
Year 2002 Publication Proceedings. Biological sciences / The Royal Society Abbreviated Journal Proc Biol Sci
Volume 269 Issue 1494 Pages 943-952
Keywords *Aggression; Animals; *Behavior, Animal; *Cyprinodontiformes; Female; Male
Abstract Aggressive contests probably occur in networking environments where information about fighting ability is conveyed both to an opponent and to individuals peripheral to the fight itself, the bystanders. Our primary aim was to investigate the relative influences of eavesdropping and prior social experience on the dynamics of aggressive contests in Xiphophorus helleri. A bystander's ability to witness an encounter was manipulated using clear, one-way mirror, and opaque partitions. After watching (or not watching) the initial contest, the bystander encountered either the winner or loser of the bout. Treatment comparisons of bystander-winner or bystander-loser contest dynamics indicated the presence or absence of winner, loser, or eavesdropping effects. Winner and loser effects had negligible influences on bystander contest dynamics. Eavesdropping significantly reduced the bystander's propensity to initiate aggression, escalate, and win against seen winners regardless of whether the watched bout had escalated or not. Though eavesdropping had relatively little effect on bystander-loser contest dynamics, bystanders were less prone to initiate aggression and win against losers that had escalated in the witnessed bout. Thus, bystanders appear to preferentially retain and utilize information gained about potentially dangerous opponents (winners or persistent losers). Our data lend clear support for the importance of eavesdropping in visually based aggressive signalling systems.
Address Department of Biology, Life Science, Room 139, University of Louisville, Louisville, KY 40292, USA. rlearl01@athena.louisville.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 0962-8452 ISBN Medium
Area Expedition Conference
Notes PMID:12028778 Approved no
Call Number refbase @ user @ Serial 498
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