Aversive Responses to Bitter Taste Quinine and Saccharose Octaacetate in the Eastern Turtle Dove Streptopelia Orientalis

27 Mar Aversive Responses to Bitter Taste Quinine and Saccharose Octaacetate in the Eastern Turtle Dove Streptopelia Orientalis

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Abstract

キニーネ,サッカロースオクタアセテート(SOA)に対するキジバト5羽の反応を,2皿選択実験によって調べた. 1.小麦粉を付着させただけの対照餌をおいて,餌場間の選択実験を行ったところ,2羽では差はみられなかったが,3羽では餌場選択実験3回中2回(67%),10回中7回(70%),7回中2回(29%)で,場所間に差がみられた.これら3羽のうち前2羽は,差が認められた場合,同じ餌場での採食量が多かったが,後1羽は選択した餌場が異なっていた. 2.にがみ物質を付着させた処理餌と対照餌との選択実験では,にがみ物質の量を少ないところから始めて次第に多くしていくとある量でキジバトは処理餌を忌避するようになった.また,その付着量から再び次第に少なくしていくと,今まで反応しなかった少量のにがみ物質にも反応するようになり,さらに量を少なくしていくと反応しなくなった.反応を示した付着量は個体によって異なっていた.1羽の個体は,キニーネには反応したが,SOAには反応しなかった. 3.キニーネとSOAを比較すると,キニーネの方がSOAより少ない量でキジバトに反応を起こさせる傾向が見られた. 4.臭いによって餌を忌避しているかどうかを確認するための選択実験を行ったところ,反応はみられなかった. 5.通常キジバトがあまり採食しない餌と,キニーネ処理餌の選択実験では,3羽中2羽の個体が処理餌を選択した. 6.以上の結果から,キジバトはにがみ物質に対して反応すること,しかし,その忌避反応は絶対的なものではなく,相対的なものであることが明らかになった.

English Abstract

Responses of 5 eastern turtle doves Streptopelia orientalis to bitter taste quinine and saccharose octaacetate (SOA) were investigated with two-dish preference tests.
1. Marked individual differences were found in preference experiments for the foraging site in which control corns coated with dour of wheat were set to two dishes. Two doves showed no preference for the site and other two rejected one site (statistically significant in 2 out of 3 and in 7 out of 10 experiments, respectively). Another dove rejected one site in an experiment and preferred the site in another one out of 7 experiments.
2. Preference experiments for quinine and flour by olfactory cue alone showed no difference and following results were considered to be caused by taste preference.
3. Treated corns coated with bitter taste and control corns were set to each dish at random in every 3-hr period of trial. Preference experiments were designed as ascendant (from smal to large dose of bitter substance) and the following descendant (from large to small dose) series. Doves that rejected treated corns at certain dose on ascendant series rejected at smaller dose on descendant series. The dose that doves showed aversive response varied individually. Four doves rejected both quinine and SOA but one dove that rejected quinine did not respond to SOA.
4. Doves tended to reject quinine-treated corns at smaller dose than SOA-treated ones both on ascendant and descendant series.
5. Doves do not prefer beans to corns among commercial mixture of grain for doves. And two of 3 doves preferred quinine-treated corns to beans coated with flour.
6. From the results above it is clear that eastern turtle dove do not prefer bitter taste quinine and SOA but they do not always reject the bitter taste.