捕食不但能直接減少獵物的數(shù)量,，也能使獵物產(chǎn)生恐懼,，從而影響獵物的分布和采食頻率等,?？謶謱?dǎo)致的實(shí)際生態(tài)后果可能與直接獵殺一樣強(qiáng)烈,。對(duì)傳粉昆蟲(chóng)而言,，恐懼能使傳粉者避開(kāi)危險(xiǎn)的采食環(huán)境，從而干擾植物傳粉,，影響植物的適合度,。然而在有多種捕食者存在和不同食物質(zhì)量的自然環(huán)境下，恐懼是如何影響傳粉者行為的尚不清楚,。中科院西雙版納熱帶植物園化學(xué)生態(tài)研究組譚墾博士領(lǐng)導(dǎo)的團(tuán)隊(duì)利用大小2種不同的胡蜂捕食蜜蜂的實(shí)驗(yàn),，對(duì)這個(gè)問(wèn)題進(jìn)行了深入的研究。
研究結(jié)果表明：1.當(dāng)胡蜂接近蜂群時(shí)，東方蜜蜂（Apis cerana）能通過(guò)結(jié)團(tuán)（ball）殺死胡蜂,。參與攻擊大型胡蜂（Vespa tropica）的蜜蜂數(shù)量是攻擊小型胡蜂（Vespa velutina）的4.5倍,。對(duì)蜜蜂而言大型的胡蜂更危險(xiǎn)。2.當(dāng)供給相同濃度糖漿時(shí),，蜂群的采集力分配,、個(gè)體的采食頻次及停留時(shí)間隨危險(xiǎn)程度而降低。3.當(dāng)供給不同濃度糖漿時(shí),，蜜蜂群體和個(gè)體都更偏好高質(zhì)量的食物,；但當(dāng)需要平衡食物質(zhì)量與捕食風(fēng)險(xiǎn)時(shí)，兩者都會(huì)減少對(duì)高風(fēng)險(xiǎn)區(qū)域（無(wú)論食物質(zhì)量）的拜訪,，但蜜蜂群體比個(gè)體表現(xiàn)出更多的恐懼,。對(duì)比群體和個(gè)體對(duì)捕食風(fēng)險(xiǎn)的不同表現(xiàn)能夠解釋捕食者是如何影響社會(huì)性蜜蜂的傳粉行為的。
相關(guān)研究成果以Fearful Foragers： Honey Bees Tune Colony and Individual Foraging to Multi-Predator Presence and Food Quality為題發(fā)表在PLoS ONE上,。在線發(fā)表在后引起了人們的廣泛關(guān)注,，多家媒體對(duì)該研究結(jié)果做了報(bào)道和評(píng)論（生物谷Bioon.com）。
生物谷推薦的英文摘要
PLoS ONE DOI: 10.1371/journal.pone.0075841
Fearful Foragers： Honey Bees Tune Colony and Individual Foraging to Multi-Predator Presence and Food Quality
Ken Tan mail,， Zongwen Hu,， Weiwen Chen， Zhengwei Wang,， Yuchong Wang,， James C. Nieh
Fear can have strong ecosystem effects by giving predators a role disproportionate to their actual kill rates. In bees， fear is shown through foragers avoiding dangerous food sites,， thereby reducing the fitness of pollinated plants. However,， it remains unclear how fear affects pollinators in a complex natural scenario involving multiple predator species and different patch qualities. We studied hornets， Vespa velutina (smaller) and V. tropica (bigger) preying upon the Asian honey bee,， Apis cerana in China. Hornets hunted bees on flowers and were attacked by bee colonies. Bees treated the bigger hornet species (which is 4 fold more massive) as more dangerous. It received 4.5 fold more attackers than the smaller hornet species. We tested bee responses to a three-feeder array with different hornet species and varying resource qualities. When all feeders offered 30% sucrose solution (w/w)， colony foraging allocation,， individual visits,， and individual patch residence times were reduced according to the degree of danger. Predator presence reduced foraging visits by 55–79% and residence times by 17–33%. When feeders offered different reward levels (15%， 30%,， or 45% sucrose),， colony and individual foraging favored higher sugar concentrations. However， when balancing food quality against multiple threats (sweeter food corresponding to higher danger),， colonies exhibited greater fear than individuals. Colonies decreased foraging at low and high danger patches. Individuals exhibited less fear and only decreased visits to the high danger patch. Contrasting individual with emergent colony-level effects of fear can thus illuminate how predators shape pollination by social bees.
