Sibling competition in common tern Sterna hirundo chicks: underlying hormonal and behavioural patterns and mechanisms ...
In avian young that are dependent on parental food provisioning, brood size and corresponding sibling competition are key environmental factors affecting present performance, future developmental trajectories, and ultimately fitness. I studied the effect of sibling competition on chick condition and...
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| Format: | Text |
| Language: | English |
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Friedrich-Schiller-Universität Jena
2008
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| Online Access: | https://dx.doi.org/10.22032/dbt.14078 https://www.db-thueringen.de/receive/dbt_mods_00014078 |
| Summary: | In avian young that are dependent on parental food provisioning, brood size and corresponding sibling competition are key environmental factors affecting present performance, future developmental trajectories, and ultimately fitness. I studied the effect of sibling competition on chick condition and possibly underlying behavioural and hormonal patterns and mechanisms in the common tern Sterna hirundo, a semiprecocial bird species exhibiting hatching asynchrony, slight sexual size dimorphism, and profound effects of chicks' mass growth on their fitness. First, I conducted an observational study on sex-, hatching rank-, and brood size-specific patterns in chick condition, success in competitive behaviour, and testosterone (T) and corticosterone (CORT) levels; second, to investigate the effect of sibling competition on chick condition, feeding rates, and T and CORT levels, I experimentally varied the extent of within-brood competition by a one-day removal of the senior siblings from two-chick broods. Overall, ... |
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