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Author Reboreda, J.C.; Clayton, N.S.; Kacelnik, A.
Title Species and sex differences in hippocampus size in parasitic and non-parasitic cowbirds Type Journal Article
Year 1996 Publication Neuroreport Abbreviated Journal Neuroreport
Volume 7 Issue 2 Pages 505-508
Keywords Animals; Birds/*physiology; Female; Hippocampus/*anatomy & histology; Male; Nesting Behavior/*physiology; Sex Characteristics; Species Specificity; Telencephalon/anatomy & histology
Abstract To test the hypothesis that selection for spatial abilities which require birds to locate and to return accurately to host nests has produced an enlarged hippocampus in brood parasites, three species of cowbird were compared. In shiny cowbirds, females search for host nests without the assistance of the male; in screaming cowbirds, males and females inspect hosts' nests together; in bay-winged cowbirds, neither sex searches because this species is not a brood parasite. As predicted, the two parasitic species had a relatively larger hippocampus than the non-parasitic species. There were no sex differences in relative hippocampus size in screaming or bay-winged cowbirds, but female shiny cowbirds had a larger hippocampus than the male.
Address (up) Instituto de Biologia y Medicina Experimental-CONICET, Buenos Aires, Argentina
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 0959-4965 ISBN Medium
Area Expedition Conference
Notes PMID:8730816 Approved no
Call Number Equine Behaviour @ team @ Serial 4798
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Author Emery, N.J.; Dally, J.M.; Clayton, N.S.
Title Western scrub-jays ( Aphelocoma californica) use cognitive strategies to protect their caches from thieving conspecifics Type Journal Article
Year 2004 Publication Animal Cognition Abbreviated Journal Anim. Cogn.
Volume 7 Issue 1 Pages 37-43
Keywords Animals; Birds/*physiology; Feeding Behavior/*physiology; Female; *Food; Male; *Memory
Abstract Food caching birds hide food and recover the caches when supplies are less abundant. There is, however, a risk to this strategy because the caches are susceptible to pilfering by others. Corvids use a number of different strategies to reduce possible cache theft. Scrub-jays with previous experience of pilfering other's caches cached worms in two visuospatially distinct caching trays either in private or in the presence of a conspecific. When these storers had cached in private, they subsequently observed both trays out of reach of a conspecific. When these storers had cached in the presence of a conspecific, they subsequently watched the observer pilfering from one of the trays while the other tray was placed in full view, but out of reach. The storers were then allowed to recover the remaining caches 3 h later. Jays cached more worms when they were observed during caching. At the time of recovery, they re-cached more than if they had cached in private, selectively re-caching outside of the trays in sites unbeknown to potential thieves. In addition, after a single pilfering trial, the jays switched their recovery strategy from predominantly checking their caches (i.e. returning to a cache site to see whether the food remained there) to predominantly eating them. Re-caching remained constant across the three trials. These results suggest that scrub-jays use flexible, cognitive caching and recovery strategies to aid in reducing potential future pilfering of caches by conspecifics.
Address (up) Sub-department of Animal Behaviour, University of Cambridge, High Street, CB3 8AA Madingley, Cambs, UK. nje23@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 1435-9448 ISBN Medium
Area Expedition Conference
Notes PMID:12827547 Approved no
Call Number Equine Behaviour @ team @ Serial 2566
Permanent link to this record