鳥兒的黎明大合唱——大自然最美的交響樂

“As I come over the hill， I hear the wood thrush singing his evening 1）lay. This is the only bird whose note affects me like music， affects the flow and 2）tenor of my thoughts， my fancy and imagination. It lifts and 3）exhilarates me…It is a medicative draught to my soul. It is an 4）elixir to my eyes and a fountain of youth to all my senses...”— Henry David Thoreau， Journal， 22 June 1853

The time is 4：24 a.m. I sit upright in bed， awakened by an inspirational choir that has just burst into sound. Vacationing in the woods of northern Vermont， I’ve taken a summer 5）sojourn back to the temperate forests of my childhood. I 6）was entitled to sleep until noon as the obvious privilege of vacation. But late sleepers in the short New England summer miss one of the best musical events of the year. The red-breasted robin is the first songster on nature’s program. Greeting the pre-dawn with a melodious， cheerful message， it reminds all of the forest 7）denizens that sunrise is 8）imminent. The robin’s instinctive timeclock is accurate within seconds： Slivers of pink and red soon slice across the dark sky， 9）interspersed with fingers of mist rising from last evening’s thundershower. Soon， that dawn 10）harbinger is joined by a couple of other robins， a trio in full song. As if not to be outdone， the white-throated sparrows join in. Their lyrical solos echo， “Oh sweet Canada， Canada”. One of my favorite voices of nature， this 11）poignant song instead says to me， “Oh， back homeagain， home-again.” It is comforting that， almost two centuries after Thoreau described New England songbirds， their melodies have remained remarkably true over time.

Within ten minutes of the robin’s wake-up lyrics， the entire hillside chorus is in full sound—red-eyed vireo， house wren， bluebird， goldfinch， ovenbird， song sparrow. By now， I’m awestruck and wide awake—no going back to bed now. Close at hand， a gang of crows engage in a 12）raucous exchange， perhaps 13）vying for a 14）tidbit of breakfast along a nearby road. They disrupt the lyrical sensation of the dawn chorus， but add a bit of humor， like sandwiching a clown act into the program of my otherwise elegant symphony.

By 5 a.m.， all the musicians are in full song. Suddenly the forest quiets for a brief lull. One new voice takes center stage. Its flutelike song and 15）resplendent trills fill every hollow of the forest， sending chills down my spine. The other birds pause，as if 16）paying tribute to this 17）exquisite soloist. Its speckled breast and reddish brown back provide fairly ordinary coloration for the star of the show， but perhaps serve as excellent 18）camouflage for a nesting parent. Despite its 19）nondescript costume， the wood thrush proclaims in song that this is the most special moment of its life. Anyone who is fortunate enough to listen to a wood thrush or to its cousins， the hermit or Swainson’s thrushes， cannot help but preserve that moment in their memories forever. Both were singing together in my Vermont dawn chorus.

In my home state of California， our dawn chorus is very different. Living near the San Francisco Bay， but also adjacent to a pond， I am awakened in summer by red-winged blackbirds interspersed with gulls and sometimes the odd western scrub-jay.

After hearing the wood thrush in the 20）spruce boughs of Vermont， my annual pilgrimage back to childhood was complete. Like an opera 21）buff， I am willing to travel great distances to hear my favorite singers. By mid-morning， the forest is relatively quiet. Having faithfully announced the new day， my feathered musical troupe moved from song to other activities—nest-building， tending to their young， 22）foraging for food， and perhaps defending their babies from 23）marauders. There is something inspirational， almost regal， about the dawn chorus. Birds celebrate each new day with great optimism. But after a stunning performance， they return to the business of survival.

Why do birds sing？ Is it an expression of happiness invoked by these feathered balls of 24）fluff 25）flitting about the forest？ Or is it survival of the fittest 26）manifested as a competition for the best voice？ Is it a physical mechanism to define territorial 27）imperative？ 28）Ornithologists remind us that bird songs are part of complex behavioral patterns， and they have dedicated extensive research to their variation and function. Technical science aside， I feel very privileged to have had a front-row seat for what is truly one of Mother Nature’s best concerts of the season.

“我走到山上，聽到一只畫眉正在為黃昏詠詩。只有這種鳥兒的歌聲觸動了我，如同音樂一般，影響了我的思緒、幻想、想象，使我感到快樂、愉悅……如同一股溫暖的氣流涌進我的靈魂深處。這是治愈我雙眼的良藥，是喚醒我所有感官的青春之泉……”——亨利·大衛·梭羅，《日記》，1853年6月22日

現在是凌晨4點24分，我被一陣剛爆發的振奮大合唱喚醒，直直地坐在床上。我正在北佛蒙特州度假，回到我的兒時舊地——氣候溫和的森林度過今夏。一覺睡到大中午是我這個在享受假期的人的特權。但睡懶覺的人會錯過在新英格蘭短暫的夏季中最棒的年度音樂盛會之一。紅胸知更鳥是這場大自然盛會的第一位歌者。它以一段優美愉悅的旋律向黎明問好，告訴所有的森林居民太陽即將升起。知更鳥的天然生物鐘無比準確，不一會兒，黑暗的天空中便出現了一道道粉紅、深紅的朝霞。前一晚的雷陣雨生成點點薄霧飄到上空，點綴著朝霞。很快，其他一些知更鳥也加入到這位黎明先知的演唱中，湊成響亮的三重唱。白喉麻雀似乎也不甘落后，加入其中。它們那熱情洋溢的獨奏在林間回蕩，“噢，可愛的加拿大，加拿大”。這是我最喜愛的大自然聲音之一，這把嘹亮的歌喉隨之對我說，“噢，重返故土，故土?！痹谒罅_描述新英格蘭的鳥鳴幾近兩個世紀后，它們的歌聲并沒有隨著時間的流逝而有所失色，這令人感到欣慰。

在知更鳥唱起喚醒之歌的十分鐘內，整個山坡便響起了大合唱——紅眼綠鵑、鷦鷯、青鳥、金翅雀、灶巢鳥、北美歌雀紛紛加入其中。