婆羅洲紅毛猩猩是三種瀕臨滅絕的紅毛猩猩之一。這種紅毛猩猩在印度尼西亞婆羅洲島碳含量豐富的泥炭沼澤森林中繁衍生息,然而其棲息地經(jīng)常出現(xiàn)大規(guī)模野火。
2015年,印尼野火造成了史上最嚴(yán)重的火災(zāi)后空氣污染。至于野火爆發(fā)的原因,則是導(dǎo)致該地區(qū)氣候格外干燥的厄爾尼諾(El Ni?o)現(xiàn)象。
與其他野火相比,泥炭地著火后主要在地下悶燒,產(chǎn)生極大量的有害氣體和顆粒物,二者皆是全球污染相關(guān)死亡和疾病的主要原因。
紅毛猩猩是眾所周知的“指標(biāo)物種”(indicator species),可以用來(lái)檢測(cè)生態(tài)系統(tǒng)的健康程度。環(huán)境變化往往會(huì)導(dǎo)致紅毛猩猩的健康和行為出現(xiàn)明顯變化。頻繁持續(xù)暴露在有毒煙霧中可能對(duì)紅毛猩猩和其他野生動(dòng)物造成嚴(yán)重后果。
有毒空氣污染也給研究人員造成了嚴(yán)重的健康和安全風(fēng)險(xiǎn)。不過(guò)衛(wèi)星圖像、全球定位系統(tǒng)(GPS)數(shù)據(jù)和聲學(xué)監(jiān)測(cè)等遙感技術(shù)被廣泛應(yīng)用于追蹤野生動(dòng)物種群,有助于我們了解各種動(dòng)物對(duì)環(huán)境變化的反應(yīng)。
自2005年以來(lái),我一直在研究印尼野生靈長(zhǎng)動(dòng)物的行為、生態(tài)學(xué)和聲音交流模式。在一項(xiàng)新研究中,我與論文合著者通過(guò)研究婆羅洲野生紅毛猩猩的聲音,分析了2015年印尼泥炭地野火有毒排放對(duì)其造成的影響。
暴露于煙霧中會(huì)引發(fā)長(zhǎng)期風(fēng)險(xiǎn)
目前,全球各地的野火越發(fā)頻繁。野火通常會(huì)產(chǎn)生濃厚的煙霧,其中含有各種有害氣體和顆粒物(PM)。就在最近的2023年6月初,加拿大野火產(chǎn)生的煙霧覆蓋了美國(guó)東海岸和中西部,天空一片橙色,還引發(fā)了公共衛(wèi)生警報(bào)。
研究表明,野火煙霧對(duì)人類(lèi)健康造成的風(fēng)險(xiǎn)包括呼吸系統(tǒng)和心血管疾病、全身炎癥和早逝等等。至于煙霧對(duì)野生動(dòng)物的影響,人們知之甚少,但在2021年和2022年發(fā)表的兩項(xiàng)研究里,美國(guó)加利福尼亞州國(guó)家靈長(zhǎng)類(lèi)動(dòng)物研究中心(California National Primate Research Center)的科學(xué)家報(bào)告的發(fā)現(xiàn)卻令人震驚。
暴露于高濃度顆粒物(特別是直徑小于2.5微米的超細(xì)顆粒物,即PM2.5)不到兩周后,圈養(yǎng)恒河猴的流產(chǎn)數(shù)量激增。而且,存活下來(lái)的恒河猴胎兒和嬰兒肺活量、免疫反應(yīng)、炎癥、皮質(zhì)醇水平、行為和記憶力都長(zhǎng)期受到影響。
在2015年印尼火災(zāi)期間,婆羅洲的空氣顆粒物濃度比相關(guān)研究中的水平還要高出近一個(gè)數(shù)量級(jí)。所以曾經(jīng)在印尼野火煙霧中喘息近兩個(gè)月的人們和野生動(dòng)物受到的潛在影響非常令人擔(dān)憂(yōu)。
煙霧中的紅毛猩猩
2015年火災(zāi)發(fā)生時(shí),我正在印尼婆羅洲森林中研究野生紅毛猩猩。我和圖阿南紅毛猩猩研究站(Tuanan Orangutan Research Station)的同事追蹤了當(dāng)?shù)氐幕馂?zāi)并在附近熱點(diǎn)地區(qū)巡邏,評(píng)估火災(zāi)蔓延到研究區(qū)域可能造成的風(fēng)險(xiǎn)。
戴好N95口罩之后,我們繼續(xù)監(jiān)測(cè)紅毛猩猩,希望了解紅毛猩猩如何應(yīng)對(duì)不斷蔓延的火災(zāi)和濃煙。野火季節(jié)開(kāi)始幾周后,我注意到雄性紅毛猩猩的“長(zhǎng)叫聲”有些異樣,這正是我研究的重點(diǎn)。
長(zhǎng)叫聲是在半英里(1公里)以上的距離內(nèi)都能夠聽(tīng)到的紅毛猩猩洪亮叫聲。紅毛猩猩是半獨(dú)居動(dòng)物,生活在分散的社區(qū)中,因此叫聲在紅毛猩猩社會(huì)里起著重要作用。成年雄性長(zhǎng)叫是為了向本地區(qū)的雌性聽(tīng)眾宣傳自己的能力,嚇跑偷聽(tīng)的雄性對(duì)手。在煙霧出現(xiàn)幾周后,我感覺(jué)雄紅毛猩猩的叫聲有些破鑼嗓——有點(diǎn)像經(jīng)常吸煙的人類(lèi)。
在火災(zāi)期間,我們觀察了紅毛猩猩44天,直到大火吞噬了研究區(qū)域?;馂?zāi)迫近后我們停止研究,跟當(dāng)?shù)叵狸?duì)以及其他政府和非營(yíng)利組織一起滅火。大火在研究區(qū)域整整燒了三周。
利用火災(zāi)發(fā)生前、期間和之后收集的數(shù)據(jù),我對(duì)婆羅洲紅毛猩猩種群的行為和健康展開(kāi)分析。我與論文合著者發(fā)現(xiàn),在火災(zāi)發(fā)生后的幾周里,紅毛猩猩的活動(dòng)減少,休息更多而且移動(dòng)距離更短,消耗的熱量則比正常情況下更多。
盡管紅毛猩猩們吃得更多動(dòng)得更少,但我們收集和測(cè)試的尿液發(fā)現(xiàn),紅毛猩猩的身體仍然在燃燒儲(chǔ)存的脂肪,這表明紅毛猩猩消耗了更多的能量。我們推測(cè)可能是炎癥導(dǎo)致,也就是人類(lèi)和動(dòng)物身體在感染或受傷時(shí)會(huì)經(jīng)歷的腫脹、發(fā)燒、疼痛和疲勞等癥狀。
哨兵的聲音
研究表明,人類(lèi)暴露在顆粒物中時(shí),呼吸道和全身會(huì)出現(xiàn)炎癥。我們想知道吸入野火煙霧會(huì)不會(huì)導(dǎo)致紅毛猩猩的聲音發(fā)生變化,就像人類(lèi)吸入香煙煙霧一樣。
在這項(xiàng)研究中,我與合著者仔細(xì)分析了野火發(fā)生前和期間四頭雄性紅毛猩猩的100多段錄音,評(píng)估其聲音對(duì)野火煙霧的反應(yīng)。研究表明,包括聲調(diào)、聲音刺耳或沙啞,以及聲音顫抖等一系列特征都反映了人類(lèi)和非人類(lèi)動(dòng)物潛在的健康和狀況。當(dāng)時(shí)我們正尋找有毒空氣對(duì)紅毛猩猩影響在聲學(xué)方面的線(xiàn)索。
在野火期間和煙霧消散后的幾個(gè)星期里,雄性紅毛猩猩叫聲比平時(shí)少。通常情況下,紅毛猩猩每天大約叫六次。然而在野火期間,紅毛猩猩叫的頻率降低了一半。紅毛猩猩的聲音越來(lái)越低沉,越來(lái)越刺耳和不規(guī)則。
總體來(lái)說(shuō),相關(guān)聲音特征與人類(lèi)和非人類(lèi)動(dòng)物出現(xiàn)炎癥、壓力和疾?。òㄐ鹿诓《荆┯嘘P(guān)。
傾聽(tīng)能發(fā)聲的物種
如果越發(fā)頻繁和長(zhǎng)時(shí)間暴露在有毒煙霧中,可能就會(huì)對(duì)紅毛猩猩和其他動(dòng)物造成嚴(yán)重后果。我們的研究凸顯出了解印尼泥炭地火災(zāi)長(zhǎng)期和深遠(yuǎn)影響的迫切需要,印尼是全世界生物多樣性最豐富的國(guó)家之一。
通過(guò)揭示紅毛猩猩聲學(xué)、行為和能量消耗變化之間的聯(lián)系,我們的研究為科學(xué)家和野生動(dòng)物管理者提供了安全監(jiān)測(cè)紅毛猩猩和其他動(dòng)物健康狀況的方法。利用被動(dòng)聲學(xué)監(jiān)測(cè)研究紅毛猩猩等可以主動(dòng)發(fā)聲的指標(biāo)物種,就能夠深入了解野火煙霧對(duì)全球野生動(dòng)物種群的影響。(財(cái)富中文網(wǎng))
本文作者溫迪·M·厄爾布(Wendy M. Erb)是康奈爾大學(xué)(Cornell University)的保護(hù)生物聲學(xué)博士后研究員。
本文已獲知識(shí)共享(Creative Commons)組織的許可,轉(zhuǎn)載自The Conversation網(wǎng)站。
譯者:夏林
婆羅洲紅毛猩猩是三種瀕臨滅絕的紅毛猩猩之一。這種紅毛猩猩在印度尼西亞婆羅洲島碳含量豐富的泥炭沼澤森林中繁衍生息,然而其棲息地經(jīng)常出現(xiàn)大規(guī)模野火。
2015年,印尼野火造成了史上最嚴(yán)重的火災(zāi)后空氣污染。至于野火爆發(fā)的原因,則是導(dǎo)致該地區(qū)氣候格外干燥的厄爾尼諾(El Ni?o)現(xiàn)象。
與其他野火相比,泥炭地著火后主要在地下悶燒,產(chǎn)生極大量的有害氣體和顆粒物,二者皆是全球污染相關(guān)死亡和疾病的主要原因。
紅毛猩猩是眾所周知的“指標(biāo)物種”(indicator species),可以用來(lái)檢測(cè)生態(tài)系統(tǒng)的健康程度。環(huán)境變化往往會(huì)導(dǎo)致紅毛猩猩的健康和行為出現(xiàn)明顯變化。頻繁持續(xù)暴露在有毒煙霧中可能對(duì)紅毛猩猩和其他野生動(dòng)物造成嚴(yán)重后果。
有毒空氣污染也給研究人員造成了嚴(yán)重的健康和安全風(fēng)險(xiǎn)。不過(guò)衛(wèi)星圖像、全球定位系統(tǒng)(GPS)數(shù)據(jù)和聲學(xué)監(jiān)測(cè)等遙感技術(shù)被廣泛應(yīng)用于追蹤野生動(dòng)物種群,有助于我們了解各種動(dòng)物對(duì)環(huán)境變化的反應(yīng)。
自2005年以來(lái),我一直在研究印尼野生靈長(zhǎng)動(dòng)物的行為、生態(tài)學(xué)和聲音交流模式。在一項(xiàng)新研究中,我與論文合著者通過(guò)研究婆羅洲野生紅毛猩猩的聲音,分析了2015年印尼泥炭地野火有毒排放對(duì)其造成的影響。
暴露于煙霧中會(huì)引發(fā)長(zhǎng)期風(fēng)險(xiǎn)
目前,全球各地的野火越發(fā)頻繁。野火通常會(huì)產(chǎn)生濃厚的煙霧,其中含有各種有害氣體和顆粒物(PM)。就在最近的2023年6月初,加拿大野火產(chǎn)生的煙霧覆蓋了美國(guó)東海岸和中西部,天空一片橙色,還引發(fā)了公共衛(wèi)生警報(bào)。
研究表明,野火煙霧對(duì)人類(lèi)健康造成的風(fēng)險(xiǎn)包括呼吸系統(tǒng)和心血管疾病、全身炎癥和早逝等等。至于煙霧對(duì)野生動(dòng)物的影響,人們知之甚少,但在2021年和2022年發(fā)表的兩項(xiàng)研究里,美國(guó)加利福尼亞州國(guó)家靈長(zhǎng)類(lèi)動(dòng)物研究中心(California National Primate Research Center)的科學(xué)家報(bào)告的發(fā)現(xiàn)卻令人震驚。
暴露于高濃度顆粒物(特別是直徑小于2.5微米的超細(xì)顆粒物,即PM2.5)不到兩周后,圈養(yǎng)恒河猴的流產(chǎn)數(shù)量激增。而且,存活下來(lái)的恒河猴胎兒和嬰兒肺活量、免疫反應(yīng)、炎癥、皮質(zhì)醇水平、行為和記憶力都長(zhǎng)期受到影響。
在2015年印尼火災(zāi)期間,婆羅洲的空氣顆粒物濃度比相關(guān)研究中的水平還要高出近一個(gè)數(shù)量級(jí)。所以曾經(jīng)在印尼野火煙霧中喘息近兩個(gè)月的人們和野生動(dòng)物受到的潛在影響非常令人擔(dān)憂(yōu)。
煙霧中的紅毛猩猩
2015年火災(zāi)發(fā)生時(shí),我正在印尼婆羅洲森林中研究野生紅毛猩猩。我和圖阿南紅毛猩猩研究站(Tuanan Orangutan Research Station)的同事追蹤了當(dāng)?shù)氐幕馂?zāi)并在附近熱點(diǎn)地區(qū)巡邏,評(píng)估火災(zāi)蔓延到研究區(qū)域可能造成的風(fēng)險(xiǎn)。
戴好N95口罩之后,我們繼續(xù)監(jiān)測(cè)紅毛猩猩,希望了解紅毛猩猩如何應(yīng)對(duì)不斷蔓延的火災(zāi)和濃煙。野火季節(jié)開(kāi)始幾周后,我注意到雄性紅毛猩猩的“長(zhǎng)叫聲”有些異樣,這正是我研究的重點(diǎn)。
長(zhǎng)叫聲是在半英里(1公里)以上的距離內(nèi)都能夠聽(tīng)到的紅毛猩猩洪亮叫聲。紅毛猩猩是半獨(dú)居動(dòng)物,生活在分散的社區(qū)中,因此叫聲在紅毛猩猩社會(huì)里起著重要作用。成年雄性長(zhǎng)叫是為了向本地區(qū)的雌性聽(tīng)眾宣傳自己的能力,嚇跑偷聽(tīng)的雄性對(duì)手。在煙霧出現(xiàn)幾周后,我感覺(jué)雄紅毛猩猩的叫聲有些破鑼嗓——有點(diǎn)像經(jīng)常吸煙的人類(lèi)。
在火災(zāi)期間,我們觀察了紅毛猩猩44天,直到大火吞噬了研究區(qū)域?;馂?zāi)迫近后我們停止研究,跟當(dāng)?shù)叵狸?duì)以及其他政府和非營(yíng)利組織一起滅火。大火在研究區(qū)域整整燒了三周。
利用火災(zāi)發(fā)生前、期間和之后收集的數(shù)據(jù),我對(duì)婆羅洲紅毛猩猩種群的行為和健康展開(kāi)分析。我與論文合著者發(fā)現(xiàn),在火災(zāi)發(fā)生后的幾周里,紅毛猩猩的活動(dòng)減少,休息更多而且移動(dòng)距離更短,消耗的熱量則比正常情況下更多。
盡管紅毛猩猩們吃得更多動(dòng)得更少,但我們收集和測(cè)試的尿液發(fā)現(xiàn),紅毛猩猩的身體仍然在燃燒儲(chǔ)存的脂肪,這表明紅毛猩猩消耗了更多的能量。我們推測(cè)可能是炎癥導(dǎo)致,也就是人類(lèi)和動(dòng)物身體在感染或受傷時(shí)會(huì)經(jīng)歷的腫脹、發(fā)燒、疼痛和疲勞等癥狀。
哨兵的聲音
研究表明,人類(lèi)暴露在顆粒物中時(shí),呼吸道和全身會(huì)出現(xiàn)炎癥。我們想知道吸入野火煙霧會(huì)不會(huì)導(dǎo)致紅毛猩猩的聲音發(fā)生變化,就像人類(lèi)吸入香煙煙霧一樣。
在這項(xiàng)研究中,我與合著者仔細(xì)分析了野火發(fā)生前和期間四頭雄性紅毛猩猩的100多段錄音,評(píng)估其聲音對(duì)野火煙霧的反應(yīng)。研究表明,包括聲調(diào)、聲音刺耳或沙啞,以及聲音顫抖等一系列特征都反映了人類(lèi)和非人類(lèi)動(dòng)物潛在的健康和狀況。當(dāng)時(shí)我們正尋找有毒空氣對(duì)紅毛猩猩影響在聲學(xué)方面的線(xiàn)索。
在野火期間和煙霧消散后的幾個(gè)星期里,雄性紅毛猩猩叫聲比平時(shí)少。通常情況下,紅毛猩猩每天大約叫六次。然而在野火期間,紅毛猩猩叫的頻率降低了一半。紅毛猩猩的聲音越來(lái)越低沉,越來(lái)越刺耳和不規(guī)則。
總體來(lái)說(shuō),相關(guān)聲音特征與人類(lèi)和非人類(lèi)動(dòng)物出現(xiàn)炎癥、壓力和疾病(包括新冠病毒)有關(guān)。
傾聽(tīng)能發(fā)聲的物種
如果越發(fā)頻繁和長(zhǎng)時(shí)間暴露在有毒煙霧中,可能就會(huì)對(duì)紅毛猩猩和其他動(dòng)物造成嚴(yán)重后果。我們的研究凸顯出了解印尼泥炭地火災(zāi)長(zhǎng)期和深遠(yuǎn)影響的迫切需要,印尼是全世界生物多樣性最豐富的國(guó)家之一。
通過(guò)揭示紅毛猩猩聲學(xué)、行為和能量消耗變化之間的聯(lián)系,我們的研究為科學(xué)家和野生動(dòng)物管理者提供了安全監(jiān)測(cè)紅毛猩猩和其他動(dòng)物健康狀況的方法。利用被動(dòng)聲學(xué)監(jiān)測(cè)研究紅毛猩猩等可以主動(dòng)發(fā)聲的指標(biāo)物種,就能夠深入了解野火煙霧對(duì)全球野生動(dòng)物種群的影響。(財(cái)富中文網(wǎng))
本文作者溫迪·M·厄爾布(Wendy M. Erb)是康奈爾大學(xué)(Cornell University)的保護(hù)生物聲學(xué)博士后研究員。
本文已獲知識(shí)共享(Creative Commons)組織的許可,轉(zhuǎn)載自The Conversation網(wǎng)站。
譯者:夏林
Bornean orangutans are one of three orangutan species, all critically endangered. They thrive in carbon-rich peat swamp forests on the Indonesian island of Borneo. These habitats are also the sites of massive wildfires.
Indonesian wildfires in 2015 caused some of the worst fire-driven air pollution ever recorded. The fires were driven by an El Ni?o climatic cycle, which caused especially dry weather in the region.
Compared to other wildfires, peatland fires smolder underground and produce exceptionally high levels of hazardous gases and particulate matter – a leading cause of global pollution-related deaths and illnesses.
Orangutans are well known as an “indicator species” – one that can serve as a proxy for the health of an ecosystem. Changes in their environments often cause conspicuous changes in the apes’ health and behavior. Frequent and persistent exposure to toxic smoke could have severe consequences for orangutans and other wildlife.
Toxic air pollution also poses serious health and safety risks for researchers. However, remote sensing techniques, such as satellite images, GPS data and acoustic monitoring, are increasingly popular ways to track wildlife populations and see how creatures respond to changes in their environments.
I have studied the behavior, ecology and acoustic communication of wild primates in Indonesia since 2005. In a new study, my co-authors and I investigated how wild orangutans in Borneo were affected by toxic emissions from Indonesia’s 2015 peatland wildfires – by studying their voices.
Smoke exposure poses long-term risks
Around the world, wildfires are on the rise. They often produce a thick blanket of haze that contains diverse hazardous gases and particulate matter, or PM. Most recently, smoke from Canadian wildfires blanketed the U.S. East Coast and Midwest in early June 2023, turning skies orange and triggering public health alerts.
Studies have shown that human health risks from wildfire smoke include respiratory and cardiovascular illnesses, systemic inflammation and premature death. Much less is known about how smoke affects wildlife, but in a pair of studies published in 2021 and 2022, scientists at the California National Primate Research Center reported alarming findings.
After less than two weeks of exposure to high concentrations of particulate matter – in particular, ultrafine particles measuring less than 2.5 microns in diameter, which are known as PM2.5 – captive rhesus macaques suffered a spike in pregnancy loss. What’s more, surviving fetuses and infants suffered long-term effects on lung capacity, immune responses, inflammation, cortisol levels, behavior and memory.
During Indonesia’s 2015 fires, Borneo’s air had particulate matter concentrations nearly an order of magnitude higher than the levels in these studies. This made the potential implications for people and wildlife who gasped through Indonesia’s wildfire smoke for nearly two months extremely worrying.
Orangutans in the haze
I was studying wild orangutans in the forests of Indonesian Borneo when the 2015 fires started. My colleagues and I at the Tuanan Orangutan Research Station tracked local fires and patrolled nearby hot spots to assess the risk of fire spreading to our research area.
Wearing N-95 masks, we continued to monitor orangutans in hopes of learning how the animals were coping with encroaching fires and thick smoke. A few weeks into the fire season, I noticed a difference in the sound of the males’ “l(fā)ong call,” which was the focus of my research.
Long calls are booming vocalizations that can be heard over distances of more than half a mile (1 kilometer). Orangutans are semi-solitary and live in dispersed communities, so these calls serve an important social role. Adult males make them to advertise their prowess to listening females in the area and to scare off any eavesdropping rival males. A couple of weeks after the smoke had appeared, I thought these males sounded raggedy – a little like humans who smoke a lot.
We observed the orangutans for 44 days during the fires, until large blazes encroached on our study area. At that point, we stopped the study to help extinguish the blazes with local firefighting teams and other government and nonprofit groups. Fires burned in our study area for three weeks.
Using data that we collected before, during and after the fires, I led an analysis of this Bornean orangutan population’s behavior and health. My co-authors and I found that in the weeks after the fires, the apes reduced their activities – resting more and traveling shorter distances – and consumed more calories than normal.
But although they were eating more and moving less, we found by collecting and testing the apes’ urine that they were still burning stored fat – a sign that they somehow were using up more energy. We hypothesized that the cause might be inflammation – the swelling, fever, pain and fatigue that human and animal bodies experience in response to infection or injury.
Sentinel sounds
Studies have shown that when humans are exposed to particulate matter, they can experience inflammation, both in their respiratory tracts and throughout their bodies. We wanted to know whether inhaling wildfire smoke would cause vocal changes in orangutans, just as inhaling cigarette smoke does in humans.
For this study, my co-authors and I carefully analyzed more than 100 sound recordings of four male orangutans that we followed before and during the fires to measure their vocal responses to wildfire smoke. Research has shown that a suite of vocal features – including pitch, vocal harshness or hoarseness, and shaky voice – reflects the underlying health and condition of both human and nonhuman animals. We were looking for acoustic clues about how this toxic air might be affecting the orangutans.
During the fires and for several weeks after the smoke cleared, these males called less frequently than usual. Normally, orangutans call about six times a day. But during the fires, their call rate was cut in half. Their voices dropped in pitch, showing more vocal harshness and irregularities.
Collectively, these features of vocal quality have been linked to inflammation, stress and disease – including COVID-19 – in human and nonhuman animals.
Listening to vocal species
Increasingly frequent and prolonged exposure to toxic smoke could have severe consequences for orangutans and other animals. Our research highlights the urgent need to understand the long-term and far-ranging effects of peatland fires in Indonesia, which is one of the most biodiverse countries in the world.
By uncovering the linkages between acoustic, behavioral and energetic shifts in orangutans, our study highlights a way for scientists and wildlife managers to safely monitor the health of orangutans and other animals. Using passive acoustic monitoring to study vocally active indicator species, like orangutans, could unlock critical insights into wildfire smoke’s effects on wildlife populations worldwide.
Wendy M. Erb is Postdoctoral Associate in Conservation Bioacoustics, Cornell University.
This article is republished from The Conversation under a Creative Commons license.