Less is more: density influences the development of behavioural life skills in trout
Theory suggests that habitat structure and population density profoundly influence the phenotypic development of animals. Here, we predicted that reduced rearing density and increased structural complexity promote food search ability, anti-predator response and the ability to forage on novel prey, a...
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Published in | Proceedings of the Royal Society. B, Biological sciences Vol. 277; no. 1696; pp. 3035 - 3043 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
England
The Royal Society
07.10.2010
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Subjects | |
Online Access | Get full text |
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Summary: | Theory suggests that habitat structure and population density profoundly influence the phenotypic development of animals. Here, we predicted that reduced rearing density and increased structural complexity promote food search ability, anti-predator response and the ability to forage on novel prey, all behavioural skills important for surviving in the wild. Brown trout were reared at three densities (conventional hatchery density, a fourth of conventional hatchery density and natural density) in tanks with or without structure. Treatment effects on behaviour were studied on trout fry and parr, whereupon 20 trout from each of the six treatment groups were released in an enclosed natural stream and recaptured after 36 days. Fry reared at natural density were faster to find prey in a maze. Moreover, parr reared at natural density were faster to eat novel prey, and showed more efficient anti-predator behaviour than fish reared at higher densities. Furthermore, parr reared at reduced densities were twice as likely to survive in the stream as trout reared at high density. In contrast, we found no clear treatment effects of structure. These novel results suggest that reduced rearing densities can facilitate the development of behavioural life skills in captive animals, thereby increasing their contribution to natural production. |
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Bibliography: | ark:/67375/V84-0D0HJBRG-F href:rspb20100561.pdf istex:D721639B0FA24996C0A8E2F7C7E955636F7D5F11 ArticleID:rspb20100561 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0962-8452 1471-2954 1471-2954 |
DOI: | 10.1098/rspb.2010.0561 |