Research press release


Nature Communications

Ecology: How birds choose which chicks to feed



今回、Stuart Westたちは、全世界の143種の鳥類がヒナに餌を与える際のヒナ育ての選好性に関する入手可能な文献(306編の論文)を収集して、こうしたヒナ育ての多様性とヒナの状態と行動との関連性を分析し、それぞれの鳥類種が生息する地域の環境条件の分析も行った。その結果、予測可能で有利な環境にいる親は、ひとかえりのヒナの中で状態が悪く、餌を強く求めているヒナに餌を優先的に与えるが、不利な環境にある親は、同じ巣にいるヒナがどれだけ餌を求めても最も状態の良いヒナに優先的に餌を与えることが判明した。


Which chicks in a nest a parent bird decides to feed depends on the quality of the local environment, finds a study in Nature Communications. This helps to resolve a long-standing question in ecology about whether parents respond to signals of need (such as how much a chick begs), or signals of quality (such as the chicks’ size) when deciding which of their offspring to feed.

While caring for their offspring, birds use up large amounts of energy by foraging for enough food to sustain their brood. Whether these parents choose to feed the chicks that beg the most (for example, this is the case for tree swallows in North America) is highly variable among different bird species, with some species instead choosing to ignore begging chicks in favour of larger offspring in the nest (for example, blue-footed boobies in the Galapagos Islands). However, which signals guide this decision has been the subject of much debate.

Stuart West and colleagues compile available literature - including 306 studies - on the parental care preferences during feeding of 143 bird species across the globe, and analyse how this variation in care relates to the condition and behaviour of their offspring, and also the environmental conditions in the area in which each species is found. They find that, in favourable and predictable environments, parents choose to feed begging chicks that are in poorer condition relative to their siblings, whereas in unfavourable environments they preferentially feed chicks that are in the best condition, regardless of how much other siblings in the nest beg.

This indicates that local environmental conditions can influence the evolution of parent-offspring communication systems, and explains why previous studies that do not consider environmental variation have not been able to identify consistent behavioural patterns across bird species.

doi: 10.1038/ncomms10985

「Nature 関連誌注目のハイライト」は、ネイチャー広報部門が報道関係者向けに作成したリリースを翻訳したものです。より正確かつ詳細な情報が必要な場合には、必ず原著論文をご覧ください。

メールマガジンリストの「Nature 関連誌今週のハイライト」にチェックをいれていただきますと、毎週最新のNature 関連誌のハイライトを皆様にお届けいたします。