Tanner et al. 2008 - hirundo @ ウィキ

このページを編集最終更新日時2012-02-08 19:04:46 (Wed)
Parus major great tit シジュウカラ

Differntial Food Allocation by Male and Female Great Tit, Parus major, Parents: Are Parents or Offspring in Control?

Tanner, M., Kolliker. M., and Richner, H. (2008) Differntial food allocation by male and female great tit, Parus major, parents: are parents or offspring in control? Anim. Behav. 75: 1563-1569.

Tanner et al. 2008.pdf

MEMO

Abstract

The distribution of food among altricial bird nestlings is the result of an interaction between parental feeding decisions and scramble competition between nestmates. Both young and parents can potentially be in control of the outcome of this interaction. In great tits, each parent feeds from a fixed location on the nest rim, thereby forcing nestlings to choose between the father's and the mother's location. It was previously found that hungry nestlings approached the female preferentially and were more likely to be fed, appearing as if females showed a stronger preference to feed hungry young than males. However, nestlings were free to move in that study, and the effects of nestling positioning could not be disentangled from those of parental food allocation decisions. Here, we experimentally divided broods into two halves and randomly assigned each half of the brood to one side of the nest cup where only one parent could feed them. One nestling in each half-brood was food deprived to manipulate short-term hunger state. Both parents showed a similar preference to feed the more hungry nestlings, suggesting that the previously observed difference was due to offspring positioning rather than active parental choice. Our study shows that food allocation is partially under nestling control and suggests that nestlings adjust positioning and begging behaviour to the profitability of a given position in the nest cup.

Outline

...

Introduction

---

「''Brood division''（親がそれぞれ別の小集団に好んで餌を与える）」は巣立ち期によく見られる（Byle 1990, Lessells 2002, Leedman and Magrath 2003）。巣立ち後のbrood divisionは雛がどちらかの親に着いていくという形で空間的に達成される。
Brood divisionは巣の中でも起こることがある（Slagsvold 1997）。
巣内でも（Bengtsson and Ryden 1981, Stamps et al. 1985, Gottlander 1987, Leonard and Horn 1996, Krebs et al. 1999）、巣立ち後でも（Slagsvold et al. 1994）、父親は大きな子を、母親は小さな子を好む傾向がある（Lessells 2002）。しかし、他のパターンが生じることもある（Harper 1985, Smiseth et al. 1998, Wheelwright et al. 2003, Whittingham et al. 2003）。
このような給餌の結果が生じるのは幾つかの筋道がある。

• 親が直接、子の表現型を判断している。
• 子は表現系によってbeggingの能力が違う。
• 巣内での位置が影響を与える。

---

シジュウカラは繁殖期を通して各親が巣のふちの決まった位置から餌を与える（Kolliker et al. 1998, Lessells et al. 2006）。雛は親が餌を与える位置を学習し、この「begging patch」を巡って競争をする（Kolliker and Richner 2004）。

---

Methods

Experimental Set-up

Statistical Analysis

Results

Begging Intensity

Food Distribution

Mass Gain

Discussion

Link

...

• トップページ

Chat