The significance of seed food in chick development re‐evaluated by tracking day‐to‐day dietary variation in the nestlings of a granivorous passerine
| Autor: | Wojciech Grzesiak, Jerzy Karg, Andrzej Wuczyński, Grzegorz Orłowski |
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| Rok vydání: | 2016 |
| Předmět: |
0106 biological sciences
biology Hatching Ecology Fauna digestive oral and skin physiology Fledge Foraging food and beverages Zoology Yellowhammer music.producer biology.organism_classification 010603 evolutionary biology 01 natural sciences Emberiza citrinella Passerine 010605 ornithology Predation biology.animal Animal Science and Zoology music Ecology Evolution Behavior and Systematics |
| Zdroj: | Ibis. 159:124-138 |
| ISSN: | 1474-919X 0019-1019 |
| DOI: | 10.1111/ibi.12410 |
| Popis: | The dietary adjustment of nestlings of granivorous birds to a seed diet and the different morphological characteristics of ingested food have rarely been examined in natural conditions. It has been suggested that the provision of cereal grains to nestlings of some seed-eating bird species in modern agroecosytems is the result of poor food conditions after agricultural intensification. We analysed the abundance of invertebrate prey in the main foraging habitat of parent birds, daily changes (from hatching to fledging) in the efficiency of cereal seed digestion, and the dietary characteristics, diet composition and prey type delivered to nestlings of the Yellowhammer Emberiza citrinella. Analysis of faecal sacs from nests located in breeding habitat with an abundant invertebrate fauna revealed no relationship between the proportion of cereal seeds in the diet of nestlings and the food supply in the main foraging sites of the parents. Neonate nestlings (1 day old) exclusively received weakly chitinised invertebrate prey (arachnids and flies), but from the second day of life the nestlings were fed a variety of highly chitinised invertebrate prey, the percentage biomass of which did not change for the remainder of the nesting period. Cereal grains started to be delivered to 3-day-old nestlings and were already efficiently digested, and the percentage biomass of this food type increased progressively with nestling age. We suggest that the provisioning of cereal grains to nestlings is not forced by external factors, such as modern agricultural intensification; rather, it is an intentional behaviour of parent birds aimed at achieving physiological adjustment to seed food in the early stages of ontogeny. This article is protected by copyright. All rights reserved. |
| Databáze: | OpenAIRE |
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