以前科学家认为鸟类没有嗅觉。但是近年来的科学研究表明，鸟类不仅有嗅觉，而且嗅觉还在鸟类择偶时起着重要作用。
Choosing a mate by sniffing
by Jason Daley
For decades, researchers thought birds lacked a sense of smell. The line of thinking was that scent gets dispersed（消散） in the wind, so it's not the most accurate tool to locate prey or keep tabs on a predator. Instead, other senses, like sight or hearing, became more fine-tuned because smell just wasn't as necessary. Recently, however, new research has overturned this idea.
decade /ˈdekeɪd/ n. 十年
researcher /rɪˈsɜːtʃə(r)/ n. 研究者（由research加上表示人的后缀-er）
sense of smell 嗅觉
line /laɪn/ n. 方式
scent /sent/ n. 气味、体味
accurate /ˈækjurət/ adj. 准确的
locate /ləʊˈkeɪt/ v. 定位
prey /preɪ/ n. 猎物
keep tabs on 仔细观察、密切留意
predator /ˈpredətə(r)/ n. 捕食者
fine-tune /ˌfaɪnˈtjuːn/ v. 微调
overturn /ˌəʊvəˈtɜːn/ v. 推翻
Now, a new study suggests that not only can birds smell, but they identify each other using the unique scent of the microbiome（微生物群） found in their preen glands located at the base of their tail feathers.
suggest /səˈdʒest/ v. 表明
identify /aɪˈdentɪfaɪ/ v. 识别
unique /juːˈniːk/ adj. 独特的
preen gland 尾脂腺
base /beɪs/ n. 基底
tail /teɪl/ n. 尾巴
feather /ˈfeðə(r)/ n. 羽毛
One way birds stay clean is by spreading around oil produced by the preen gland. It's thought that the oil is primarily used to preserve feathers, but previous studies of bird olfaction（嗅觉） have also shown that some species communicate using the oil.
spread /spred/ v. 使扩散、涂抹
primarily /praɪˈmer(ə)li/ adv. 主要地（由primary加后缀-ly变成副词）
preserve /prɪˈzɜːv/ v. 保护
species /ˈspiːʃiːz/ n. 物种（单数和复数都是species）
communicate /kəˈmjuːnɪkeɪt/ v. 交流、沟通
For a new paper published in the Journal of Experimental Biology, researchers led by Danielle Whittaker, an ornithologist（鸟类学家） at Michigan State University, investigated how these scents are produced. The team injected antibiotics directly into the preen glands of dark-eyed juncos（灯草雀）, a North American songbird, then analyzed how that changed the bacterial（细菌的） communities in the preen oil and subsequently, the odor（气味）. They also began culturing the bacteria found in the preen oil of other juncos.
paper /ˈpeɪpə(r)/ n. 论文
publish /ˈpʌblɪʃ/ v. 发表
journal /ˈdʒɜːn(ə)l/ n. 期刊
experimental /ɪkˌsperɪˈment(ə)l/ adj. 实验的（由experiment加后缀-al变成形容词）
investigate /ɪnˈvestɪɡeɪt/ v. 调查研究
inject /ɪnˈdʒekt/ v. 注射
antibiotic /ˌæntibaɪˈɒtɪk/ n. 抗生素
dark-eyed 有着黑眼睛的
songbird /ˈsɒŋbɜːd/ n. 叫声像唱歌的鸟（由song和bird组成）
analyze /ˈæn(ə)laɪz/ v. 分析
community /kəˈmjuːnəti/ n. 社区、菌落
preen oil 尾脂
subsequently /ˈsʌbsɪkwəntli/ adv. 随之而来地（由subsequent加后缀-ly变成副词）
culture /ˈkʌltʃə(r)/ v. （在实验室）培养
bacterium /bækˈtɪəriəm/ n. 细菌（bacteria /bækˈtɪəriə/ 是复数）
They found that all of the bacteria in the birds' microbiome produce certain scent notes. When combined, the bacteria produce the birds' personal scent, which in turn has an impact on their mating success.
note /nəʊt/ n. 基本气味、气味元素
combine /kəmˈbaɪn/ v. 合并
in turn 接下来
impact /ˈɪmpækt/ n. 影响
mate /meɪt/ v. 求偶、交配
"The odors produced by birds are unique to them and allow other birds to gain crucial information regarding the mating process," Whittaker says in a statement. "Alter that bacteria and the bird could be less attractive to potential mates." Next, the team would like to find out exactly what type of information the microbiome, and therefore the odor, is relaying（传送） to other birds.
crucial /ˈkruːʃ(ə)l/ adj. 至关重要的
regarding /rɪˈɡɑːdɪŋ/ prep. 关于
process /ˈprəʊses/ n. 过程
statement /ˈsteɪtmənt/ n. 陈述、说明
alter /ˈɒltə(r)/ v. 改变、修改
potential /pəˈtenʃ(ə)l/ adj. 潜在的
mate /meɪt/ n. 配偶、伴侣
The next step for Whittaker is to see just how much the bacteria in the preen gland impacts the juncos' love lives. Over the past few decades, researchers have found that juncos living in urban areas no longer breed with juncos from the woodlands. She hopes to investigate whether changes in each population's microbiome are causing them to become reproductively（生殖上） isolated from one another. It's possible that city birds and country birds literally do not like the smell of one another.
impact /ɪmˈpækt/ v. 影响（它做动词和做名词时发音不同）
urban /ˈɜːb(ə)n/ adj. 城市的
breed /briːd/ v. 繁殖
woodland /ˈwʊdlənd/ n. 林地（由wood和land组成）
cause /kɔːz/ v. 造成、导致
isolate /ˈaɪsəleɪt/ v. 隔离
literally /ˈlɪt(ə)r(ə)li/ adv. 确实（表示强调）
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