It's 5000 BCE in the verdant swamps of North America, and this young deer has no idea it’s being hunted. Suddenly, an alligator hurtles out of the water at almost 50 kilometers an hour, locking its jaws around its prey and swinging wildly in a signature move known as the death roll. This deer never stood a chance, but then, nothing in this region can compete with this apex predator. These alligators easily devour the birds, turtles, and small fish living in what’s known today as Everglades National Park. But despite ruling the swamp for millennia, the last 500 years have brought deadly new predators that challenge the alligators’ reign. And the origins of these international invaders are just as unexpected as their impact on the Everglades.
西元前五千年,在北美一處 蔥蔥鬱鬱的沼澤地, 有隻年輕的鹿沒有發現 自己已成了獵物, 轉眼間,短吻鱷以近乎每小時 五十公里的速度衝出水面, 死咬著獵物不放,在地上狂暴翻滾, 放出名為「死亡翻滾」的招牌必殺技。 鹿絲毫沒有勝算, 當時,也確實沒有人能夠匹敵 短吻鱷這種頂級掠食者。 短吻鱷能輕鬆吃下鳥、烏龜, 和住在現址大沼澤地國家公園的小魚。 即使短吻鱷制霸沼澤地已有千年之久, 五百年前出現的這些生物 撼動了短吻鱷千年不搖的地位。 這些生物的起源,跟牠們為 大沼澤地公園帶來的衝擊 都出人意料之外。
We tend to think of swamps as hostile landscapes since they’re overflowing with plant and animal life. But all this biodiversity makes these environments vital to regional food webs. And the Everglades are no exception. The park's subtropical climate can support species from around the world, and its borders are full of ecotones— transition areas between habitats— that connect the region’s freshwater prairies, rocky pinelands, mangrove forests, and more. Human activity has made the region even more biodiverse, developing Florida into a major port that welcomes countless human and non-human migrants.
沼澤地在我們的想像裡可能充滿危險, 因為沼澤裡有數不清的動植物物種。 但正是這樣的生物多樣性 讓周遭地區的食物鏈 高度依賴沼澤環境, 大沼澤地也不例外。 大沼澤地國家公園位在副熱帶氣候區, 能夠養活世界上許多物種, 而且園區邊界都是生態過渡帶, 也就是兩種生態區的交界, 連接了淡水地區的草原地帶、 岩質松林地、紅樹林等生態區。 人類活動又為大沼澤地增添生物多樣性, 將佛羅里達州打造成港口, 迎接大量人類和動植物物種移入此地。
In the 1500s, Spanish colonizers brought wild boar to the area, which quickly multiplied and uprooted the wetlands. They devoured alligator eggs and spread European parasites to local panthers. Then, in the 1800s, Florida’s shipping industry exploded, bringing all manner of new invasive species. Brazilian peppertrees blocked out the sun, water hyacinths clogged the rivers, and brown anole lizards upset the food chain. Alligator populations mostly endured this onslaught, but in the late 19th century, human intervention kicked things up a notch. Government and business officials wanted to turn the Everglades into farmland and began building canals to drain the swamp. They also planted non-native trees which crowded out the plants local birds relied on for food and shelter, which in turn limited the alligators’ supply of prey.
16 世紀時,西班牙將野豬 引進現今的佛羅里達州, 牠們快速繁殖,不久後就徹底 改變該地區的生態樣貌: 牠們張口吞食鱷魚蛋,散播 歐洲來的寄生蟲到當地豹類身上。 19 世紀時,佛羅里達州的 港口貿易興旺了起來, 各式各樣的物種因此得以進出。 巴西胡椒木擋住陽光, 布袋蓮讓河水停滯, 沙氏變色蜥打亂了整體食物鏈。 短吻鱷撐過這次對生態系的猛攻, 但在 19 世紀晚期, 人類的干涉讓情況變得更糟: 政府和商人們想把 大沼澤地變成農地, 開始抽乾沼澤地的水,建造運河。 除此之外,他們還種下非原生種的樹, 那些樹種讓當地鳥類用來覓食 和居住的樹種沒地方生長, 因此減少了短吻鱷的獵物數量。
Interventions like this wreaked havoc on the Everglades for decades, until a conservationist named Marjory Stoneman Douglas finally came to their defense. In 1947, Douglas published a landmark book explaining that the Everglades were not only a unique and precious ecosystem, but that the region’s most fearsome residents were actually vital to sustaining it. During the wet season, alligators are constantly shaping the muddy landscape, drawing lines with their bodies and digging holes with their snouts, claws, and tails. In the dry season, these indentations become essential watering holes and firebreaks, maintaining and protecting the swamp’s other residents.
像這樣的種種人為干涉 摧殘了大沼澤地整整數十年, 直到有天,環境保護主義者 瑪裘莉・史東曼・道格拉斯 挺身而出。 1947 年,道格拉斯出版一本 具重大意義的書,向大眾訴說 大沼澤地不只是個特別且珍貴的生態園區, 且該地區最被懼怕的生物,其實是 維持該地生態最重要的一環。 在雨季期間, 短吻鱷們不停在泥地上「施工」, 用身體畫線, 用鼻部、爪子和尾巴挖洞。 在乾季期間, 這些坑洞成為儲水池和防火區, 保護沼澤地區的其他動物。
In the wake of Douglas’ book, Everglades National Park was established to formally begin protecting the landscape and its scaly stewards. But outside the park, conditions were brewing for the most dangerous invasion yet. Over the next 40 years, the exotic pet trade brought parakeets, iguanas, and relatives of piranhas to the region. In the 1990s, Burmese pythons became a cheap, popular pet for many Floridians. Some snake owners released their pets into the wild when they grew too large. But the python population really exploded in 1992 when a hurricane destroyed a breeding facility and released countless snakes into the wild. Since then, pythons have been connected to a 90% decrease in some local mammal populations, decimating the alligators’ food supply. And with help from other invasive reptiles like black and white tegus— giant lizards who devour alligator eggs— these snakes have made a serious play for the top of the local food chain.
因道格拉斯出書的驚醒 而設立了大沼澤地國家公園 開始正式地保護該地區景觀 及其有鱗的管家。 但在園區外面, 最危險的侵入行動正在慢慢成形。 那之後 40 年,與各國的動物交易 讓長尾鸚鵡、美洲鬣蜥 和食人魚進入了該地區。 1990 年代,便宜的緬甸蟒蛇 成了佛羅里達人的熱門寵物, 有些飼主在蟒蛇 長得太大後就將其野放。 但蟒蛇數量真正大爆炸的 時期是落在 1992 年, 颶風摧毀了一個蟒蛇養殖場, 讓無數隻蟒蛇脫離控制。 從那起事件之後,蟒蛇就導致 某些當地原生哺乳類數量 整整減少 90%, 間接影響到短吻鱷的食物供給。 藉由其他侵略性爬蟲類的幫忙, 如阿根廷黑白南美蜥, 也就是會吃短吻鱷的蛋的巨大爬蟲類, 這些蟒蛇確實地爬上當地食物鏈的頂端。
Today, Florida ranks among the regions with the most invasive species in the world. Some researchers suggest hunting these invaders down, while others recommend bringing in yet more creatures to balance the scales, such as releasing insects to eat invasive plants. It might seem absurd to try solving this problem with more foreign fauna. But perhaps a new arrival could fight invaders and feed the alligators— giving them the boost they need to reclaim their ancient home.
現在的佛羅里達是全世界 棲息物種的侵略性最高的地方。 有些學者提議消滅侵略過來的物種, 有些則提議引進更多種 生物來平衡衝擊, 比如說,引進昆蟲來吃掉具侵略性的植物。 用外來種制衡外來種看似荒謬, 但新來的物種也有可能 可以制衡入侵者並養活短吻鱷, 讓短吻鱷重整旗鼓, 奪回昔日的平常生活。