近日,，行為生態(tài)學領(lǐng)域刊物《行為生態(tài)學》（Behavioral Ecology）在線發(fā)表了中科院成都生物研究所兩棲爬行動物研究室唐業(yè)忠課題組研究人員的研究成果,，研究發(fā)現(xiàn)動物也有“面子”問題。
雄性之間競爭的目的大多是為了獲得資源,、領(lǐng)地,、配偶，而最終目的則是為了成功交配,，以繁殖后代,。雄性之間的競爭往往伴隨著高能量消耗和被天敵捕食的巨大風險。然而,，雄性是否能獲得配偶,，最終決定權(quán)卻掌握在雌性手中。因此,，可以推測的是：雌性的存在與否以及雌性對雄性的態(tài)度有可能影響雄性之間的競爭策略,。例如，對于人類來說,，在有女性在場時,，男性更勇敢。那么,，對于動物來講,，事實是否果真如此？
崔建國博士設(shè)計了一個實驗,，在動物身上驗證了這一假設(shè),。通常情況下，兩只雄性非洲爪蟾（Xenopus laevis）放在同一只缸中競叫時,，會產(chǎn)生明顯的勝利者和失敗者,，失敗者受到明顯地壓制，較少發(fā)出鳴叫,。當研究者給成對的雄性競爭者播放雌性接受鳴叫（處于發(fā)情狀態(tài)的鳴叫聲）時,，勝利者和失敗者均顯著增加鳴叫。有趣的是,，有一半原來的失敗者能反敗為勝,，轉(zhuǎn)變成勝利者。而且，相關(guān)分析也表明,，在雄性競爭前（即每只缸中放一只動物單獨鳴叫）,，動物的鳴叫時間與體重呈顯著正相關(guān)（即體重越大，鳴叫時間越長）,，而當兩只雄性放在同一只缸中競爭時,，這種相關(guān)關(guān)系消失，說明部分“機會主義者”隱藏了其真實的實力,，采取保守的競爭策略,，而當聽到雌性接受鳴叫時，這種相關(guān)關(guān)系重新出現(xiàn),，說明部分“機會主義者”在有雌性出現(xiàn)時,，采取激進的競爭策略，露出真本事,，奮起反擊,，從而反敗為勝。
本研究揭示：雄性之間的競爭策略可根據(jù)雌性的態(tài)度而轉(zhuǎn)變,，從而有助于我們理解為什么女性在場時男性比較要面子這一問題的生物學基礎(chǔ),。研究得到國家自然科學基金青年基金、中國科學院重要方向項目子課題-生物適應(yīng)與協(xié)同進化和“百人計劃”項目的資助,。（生物谷Bioon.com）
doi:10.1093/beheco/arr187
PMC:
PMID:
Male competition strategies change when information concerning female receptivity is available
Fei Xua, Jianguo Cuia, Jing Songa, Steven E. Brauthb and Yezhong Tanga
Males compete for access to resources or females or to influence female mate choice in many animal species. Male competitive activities are accompanied by high-energy expenditure and increased risk of predator detection. We therefore hypothesized that information predicting female receptivity could affect male competition strategies in species in which such information is available to males. To test this hypothesis, male–male vocal competition was assessed in Xenopus laevis, a species in which females can produce receptive (rapping) and unreceptive (ticking) calls. Male vocalizations were recorded when 1) males called alone, 2) 2 paired males with similar body mass called competitively and established dominance, and 3) the paired males called when listening to playbacks of either rapping or ticking calls. On average, rapping but not ticking playbacks increased male calling and in many cases induced previously nondominant males to call more than their rivals. Moreover, males adopted either of 2 competitive strategies: an assertive strategy in which some individuals always called at a high rate and an opportunistic strategy in which some individuals only called at a high rate in the presence of receptive female call playbacks. Body mass and call rate were correlated only when males called alone or when rapping calls were played back. These results support the idea that male–male competition strategies can be influenced by information indicating that receptive females are present.
