分类必应美图下的文章

Lauwersmeer国家公园上空的椋鸟群，荷兰 Starlings flock over Lauwersmeer National Park, Netherlands (© Frans Lemmens/Alamy)

Moving as one

After the nesting and breeding seasons of spring and summer have passed, starlings become highly social birds, often gathering in flocks that number in the thousands. These flocks sometimes take the form of a murmuration—when the birds form a group large and dense enough that they appear to move together as a single organism, even if the movements seem arbitrary. Though scientists still don't quite understand how the individual starlings in a murmuration coordinate their tight, fluid formations, the behavior is thought to be a way to confuse predators.

Imagine if you're a falcon on the hunt and you see a small group of starlings—an easy meal if you catch one. But if the starlings spot the predator first, they may form a murmuration, swooping and diving as one, making it difficult for the falcon to isolate and hunt an individual starling.

比弗湖自然中心内光秃秃的树和红盖鳞毛蕨，纽约 Bare trees and autumn ferns in Beaver Lake Nature Center, New York (© Chris Murray/Alamy)

Reflecting on fall

Some of the best things about fall in many parts of the country are the amazing colorful displays across the landscape. While the trees here in Beaver Lake Nature Center, near Syracuse, New York, are already bare, the autumn ferns here cast a radiant reflection on the water. This 661-acre natural area contains a 200-acre glacial lake that draws migrating Canadian geese to its shores. Visitors may also see more than 200 species of other birds and over 800 varieties of plants. The nature center is also a destination for cross-country skiing in the winter, as well as kayaking and canoeing in the summer months.

马蹄寺风景区内的马蹄寺和石窟，中国甘肃省 The Mati Si (Horse's Hoof Temple) and grottoes of Mati Si Scenic Area, Gansu province, China (© Ana Flašker/Alamy)

A cliff-hanging complex of temples

Feast your eyes on the colorful Mati Si (Horse's Hoof Temple) and its cliffside complex of sandstone grottoes and wooden pavilions. To understand the mythical origin of the Horse's Hoof Temple, you have to squint your eyes a bit. Then you might be able to see the hoof marks left by a frightened longma, the fabled winged dragon horse that purportedly landed here thousands of years ago. What you can't see is the claustrophobic network of tunnels connecting the seven floors and seven grottoes to the Mati Si pagoda, which itself is 200 feet high and holds hundreds of Buddha statues.

Mati Si lies within the grasslands of China's Gansu province along the Hexi Corridor of what was once China's Northern Silk Road. There's no bus service to the temple so you'll have to grab a taxi or, like the mythical dragon horse that left its imprint here, hoof it.

锡特卡的港口，阿拉斯加 View of the harbor in Sitka, Alaska (© Blaine Harrington III/Alamy)

Sitka shines on Alaska Day

In honor of Alaska Day, we're in the harbor of Sitka, Alaska, the former capital of Russian America in the early 19th century, when it was called Novo-Arkhangelsk. It was here on this day in 1867 that officials of the Russian Empire formally transferred the Territory of Alaska to the United States in a sale for $7.2 million, or just around 2 cents per acre. It seems an astonishingly small price today, but at the time, opponents called it 'Seward's Folly' after then-Secretary of State William H. Seward, who negotiated the deal. Few Americans moved to the 'Last Frontier' at first, but in the 1890s, when gold was discovered in the Yukon and Alaska, a rush of prospectors and others began a wave of settlers in the territory. Ever since, Alaska, with its vast natural resources and staggering beauty, has been a prized American domain and an enduring symbol of American wilderness.

布里瓦德附近的皮斯加国家森林，北卡罗来纳州 View of Pisgah National Forest near Brevard, North Carolina (© Adam Jones/Danita Delimont)

Fog above the forest

Today we're looking out over Pisgah National Forest, which was established on this day in 1916. One of the first national forests in the eastern United States, it's comprised of more than 500,000 acres of mountainous peaks, cascading waterfalls, and heavily forested slopes. With hundreds of miles of trails, Pisgah is a popular place for hiking, backpacking, road biking, mountain biking, fishing, and rock climbing.

The land here was first set aside as a public forest with approximately 86,700 acres that were previously part of the Biltmore Estate owned by George Vanderbilt II. But when he passed away in 1914, his wife, Edith Vanderbilt, sold the land to the federal government for $5 an acre, fulfilling her husband's wishes to create the core of the Pisgah National Forest.

田里的拖拉机和装载着卷心菜的拖车，奥地利圣珀尔滕 View of a tractor and trailers of cabbage in a field in Sankt Pölten, Austria (© Stephan Zirwes/Getty Images)

It's harvest time on World Food Day

This tractor is transporting trailers full of one of the world's most versatile veggies: cabbage. A stalwart in Slavic recipes, a key ingredient in Korean kimchi, and essential to that sauerkraut on your ballpark dog, it's the perfect cosmopolitan crop to represent World Food Day.

Organized annually by the Food and Agriculture Organization of the UN, World Food Day puts a spotlight on the issue of food security: The ability of individuals or communities to readily access nutritious food. This year, food security is of extra concern as the COVID-19 pandemic has further threatened already vulnerable communities. But the FAO says these threats could be turned into opportunities to rebuild food supply chains in more targeted, cooperative, and efficient ways—so they've given 2020's World Food Day the theme 'Grow, Nourish, Sustain. Together.'

堡垒山上的珀纳里城堡，法加拉斯山，罗马尼亚 Poenari Castle on Mount Cetatea, Făgăraș Mountains, Romania (© porojnicu/Getty Images)

A castle fit for a count

Peeking out above the trees in the Făgăraș Mountains of Romania is Poenari Castle, an ancient structure whose reputation is steeped in history and legend. In the 15th century this castle was occupied by the notoriously ruthless ruler Vlad III, aka Vlad the Impaler, aka Vlad Dracula. Vlad wasn't a vampire, but he was known for treating his enemies with particular cruelty. His bloody resistance to Ottoman encroachment would make him a national hero and the subject of much folklore, some of it gruesome. These tales are likely what inspired author Bram Stoker to name his fictional vampire Count Dracula.

Poenari Castle continued to be used following Vlad's death in 1476 but was abandoned decades later. It fell into ruin over the centuries, as earthquakes and landslides sent parts of the building down the cliff and into the Argeș River below. Visiting the ruins today requires determination and stamina—it's a 1,480-step climb to the citadel walls, unless you're able to take the form of a bat and fly to the top.

A monastery in the mountain

Built into the side of a mountain in the Azat Valley of Armenia, Geghard Monastery is one of the most-visited tourist destinations in the country. The location of the monastery has been inhabited for millennia and venerated by locals since the pre-Christian era due to the spring which emanates from one of the caves in the mountainside. The monastery was originally founded in the 4th century by Saint Gregory the Illuminator—the patron saint of the Armenian church—though none of the original buildings survive.

The buildings comprising the existing complex were begun in the 13th century and are now regarded as some of the best-preserved examples of medieval Armenian architecture. But what really makes the complex unique are the monastic cells and chapels hewn directly into the mountain itself, with elaborate bas relief ornamentations and multiple exquisite examples of Armenian stone crosses, or 'khachkar,' throughout. Designated a UNESCO World Heritage Site, protections extend to both the monastery complex and the surrounding countryside, making a trip there an opportunity to step back into the medieval world.

俯瞰正在飞越洛斯罗克斯群岛国家公园的美洲红鹳，委内瑞拉 Aerial view of American flamingos flying over Los Roques Archipelago National Park, Venezuela (© Cristian Lourenco/Getty Images)

Birds of a feather

Today is World Migratory Bird Day in Latin and South America, so to honor the occasion we've chosen these flamingos, rising above the Caribbean Sea off the coast of Venezuela. Changes in daylight hours and food availability can trigger seasonal migrations in many bird species, including flamingos. American flamingos like these will migrate relatively short distances, usually to ensure a steady food supply. Found mainly throughout the Caribbean, their range extends as far north as southern Florida.

The nonprofit sponsor of World Migratory Bird Day, Environment for the Americas, focuses its efforts on conserving habitats for the hundreds of bird species that migrate along north-south routes in the Americas, from Alaska and Canada to Argentina and Chile and places in between. Most of these migratory birds use established flight paths called flyways to travel between their breeding grounds and overwintering areas. These aerial highways tend to avoid obstacles such as mountain ranges and oceans, running parallel to topographical barriers and following routes along coasts or major river valleys. Birds migrating through North America follow four main flyways, the Atlantic, Mississippi, Central, and Pacific. Because the birds need adequate food and shelter at stopover points along the way, conservation of habitats through these corridors is especially important to the birds' survival. This year, with wildfires raging across the American West, the Pacific flyway has been especially peril

While October 10 is World Migratory Bird Day in Mexico, Central, and South America, bird lovers in the US and Canada observe this conservation event on the second day in May. But wherever you live, every day is a good day to pick up some binoculars and watch the birdlife outside your own window.

Falling for Tennessee

Although it might not look like it in this image of a tranquil fall day, Roaring Fork in the Great Smoky Mountains National Park has earned its ferocious name. The stream descends 2,500 feet over just 2 miles—a steep drop. After heavy rains, Roaring Fork transforms into a whitewater rush, the sound echoing off the mountainsides. But during drier spells, the stream quiets to more of a babbling brook, as seen here along the Roaring Fork Motor Nature Trail. The 5.5-mile popular loop drive passes waterfalls, well-preserved historic log cabins, and scenic overlooks of a forest that during this time of year reaches its fall color peak, exploding in bold yellows, oranges, and reds. These are just some of the things that make Great Smoky Mountains the most popular national park in the country.

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