相关背景内容： | Hawaii's diverse natural scenery, warm tropical climate, abundance of public beaches, oceanic surroundings, and active volcanoes make it a popular destination for tourists, (wind) surfers, biologists, and volcanologists alike. Due to its mid-Pacific location, Hawaii has many North American and Asian influences along with its own vibrant native culture. Hawaii has over a million permanent residents, along with many visitors and U.S. military personnel. Its capital is Honolulu on the island of Oʻahu.
The state encompasses nearly the entire volcanic Hawaiian Archipelago, which comprises hundreds of islands spread over 1,500 miles (2,400 km). At the southeastern end of the archipelago, the eight "main islands" are (from the northwest to southeast) Niʻihau, Kauaʻi, Oʻahu, Molokaʻi, Lānaʻi, Kahoʻolawe, Maui and the Island of Hawaiʻi. The last is the largest and is often called the "Big Island" to avoid confusing the island with the state or archipelago. The archipelago is physiographically and ethnologically part of the Polynesian subregion of Oceania.
Hawaii is the 8th-smallest, the 11th-least populous, but the 13th-most densely populated of the 50 U.S. states. Hawaii's ocean coastline is about 750 miles (1,210 km) long, which is fourth in the United States after those of Alaska, Florida and California.
Hawaii is the only U.S. state not located in the Americas and the only state with an Asian plurality. It and Arizona are the only two states that do not observe daylight saving time, and Hawaii and Alaska are the only two states that are not in the contiguous United States.
Flora and fauna
Because the islands are so far from other land habitats, life before human activity is said to have arrived by the “3 W’s”: wind (carried through the air), waves (brought by ocean currents), and wings (birds, insects, and whatever they brought with them). This isolation, and the wide range of environments (extreme altitude, tropical climate) produced a vast array of endemic flora and fauna (see Endemism in the Hawaiian Islands). Hawaii has more endangered species and has lost a higher percentage of its endemic species than any other U.S. state.[47] One endemic plant, Brighamia, now requires hand-pollination – its natural pollinator is presumed to be extinct.[48] The two species of Brighamia – B. rockii and B. insignis – are represented in the wild by perhaps 120 individual plants. In order to ensure that these plants set seed, biologists rappel down 3000-foot cliffs to brush pollen onto their stigmas.[49]
The relatively short time that the existing main islands of the archipelago have been above the surface of the ocean (less than 10 million years) is only a fraction of time span over which biological colonization and evolution have occurred in the archipelago.
The islands are well known for the environmental diversity that occurs on high mountains within a trade winds field. On a single island, the climate can differ around the coast from dry tropical (< 20 in or 500 mm annual rainfall) to wet tropical; and up the slopes from tropical rainforest (> 200 in or 5000 mm per year) through a temperate climate into alpine conditions of cold and dry climate. The rainy climate impacts soil development, which largely determines ground permeability, which affects the distribution of streams, wetlands, and wet places.
Protected areas
Silversword
Endemic Haleakalā Silversword near Haleakalā summit
Several areas in Hawaii are under the protection of the National Park Service.[50] Hawaii has two national parks: Haleakala National Park near Kula, on Maui, includes Haleakalā, the dormant volcano that formed east Maui; and Hawaii Volcanoes National Park in the southeast region of the Island of Hawaiʻi, which includes the active volcano Kīlauea and its various rift zones.
There are three national historical parks: Kalaupapa National Historical Park in Kalaupapa, Molokaʻi, the site of a former Hansen’s disease colony; Kaloko-Honokōhau National Historical Park in Kailua-Kona on the Island of Hawaiʻi; and Puʻuhonua o Hōnaunau National Historical Park, an ancient place of refuge. Other areas under the control of the National Park Service include Ala Kahakai National Historic Trail on the Big Island and the USS Arizona Memorial at Pearl Harbor on Oʻahu.
The Papahānaumokuākea Marine National Monument was proclaimed by President George W. Bush on June 15, 2006. The monument covers roughly 140,000 square miles (360,000 km2) of reefs, atolls and shallow and deep sea out to 50 miles (80 km) offshore in the Pacific Ocean, larger than all of America’s National Parks combined.[51]
Climate
See also: List of Hawaii tornadoes and Climate of Hawaii
Road to Hana through rainforest
Hawaii’s climate is typical for the tropics, although temperatures and humidity tend to be a bit less extreme due to near-constant trade winds from the east. Summer highs are usually in the upper 80s °F, (around 31 °C) during the day and mid 70s, (around 24 °C) at night. Winter day temperatures are usually in the low to mid 80s, (around 28 °C) and (at low elevation) seldom dipping below the mid 60s (18 °C) at night. Snow, not usually associated with the tropics, falls at 4,205 metres (13,796 ft) on Mauna Kea and Mauna Loa on the Big Island in some winter months. Snow rarely falls on Haleakala. Mount Waiʻaleʻale, on Kauaʻi, has the second-highest average annual rainfall on Earth, about 460 inches (11,684.0 mm). Most of Hawaii has only two seasons: the dry season from May to October, and the wet season from October to April.[52]
The warmest temperature recorded in the state is 100 °F (38 °C) (making it tied with Alaska as the lowest high temperature recorded in a U.S. state) in Pahala on April 27, 1931. Hawaii's all-time record low temperature is 12 °F (−11 °C) observed in May 1979 on the summit of Mauna Kea. Hawaii is the only state to have never recorded sub-zero Fahrenheit temperatures.
Local climates vary considerably on each island, grossly divisible into windward (Koʻolau) and leeward (Kona) areas based upon location relative to the higher mountains. Windward sides face cloud cover, so resorts concentrate on sunny leeward coasts. |
相关背景内容： | Flightless birds are birds that have evolved the inability to fly.[1] There are about 40 species in existence today,[2] the best known being the ratites (ostrich, emu, cassowary, rhea and kiwi) and the penguins.
The smallest flightless bird is the Inaccessible Island Rail (length 12.5 cm, weight 34.7 g). The largest (both heaviest and tallest) flightless bird, which is also the largest living bird, is the ostrich (2.7 m, 156 kg).
Flightless birds are the easiest to take care of in captivity because they do not have to be caged. Ostriches were once farmed for their decorative feathers. Today they are raised for meat and for their skins, which are used to make leather.
There were also other families of flightless birds, such as the now extinct Phorusrhacidae, that evolved to be powerful terrestrial predators.
Many domesticated birds, such as the domestic chicken, and domestic duck, have lost the ability to fly, though their wild ancestors, the red junglefowl and mallard, respectively, are perfectly capable of flight.
Flightlessness has evolved in many different birds independently. However, taking this to a greater extreme, the terror birds, Gastornithiformes and dromornithids (all extinct) all evolved the similar body shapes: flightlessness, long legs, long necks, big heads, yet none of them were closely related. They also share the trait of being giant, flightless birds with vestigial wings, long legs, and long necks with the ratites, although they are not related.[3][4]
Divergences and losses of flight within ratite lineage occurred after the K/T[clarification needed] boundary’s mass extinction wiped out all non-avian dinosaurs and large vertebrates 65 Ma [5] The immediate evacuation of niches following the mass extinction provided opportunities for Palaeognathes to distribute and occupy novel environments. New ecological influences selectively pressured different taxon to converge on flightless modes of existence by altering them morphologically and behaviorally. The successful acquisition and protection of a claimed territory selected for large size and cursoriality in Tertiary ancestors of ratites [6] Temperate rainforests dried out throughout the Miocene and transformed into semi arid deserts causing habitats to be widely spread across the growingly disparate landmasses. Cursoriality was an economic means of traveling long distances to acquire food that was usually low laying vegetation and more easily accessed by walking [6] Traces of these events are reflected in ratite distribution throughout semi-arid grasslands and deserts today [7]
Gigantism and flightlessness are almost exclusively correlated[clarification needed]. This is mostly observed in islands lacking predators and competition. However, ratites occupy environments that are mostly occupied by a diverse amount of mammals.[8] It is thought that they first originated through allopatric speciation caused by breakup of the supercontinent Gondwana.[9] However recent evidence suggests this hypothesis first proposed by Joel Cracraft in 1974 is incorrect.[10] Rather ratites arrived in their respective locations via a flighted ancestor and lost the ability to fly multiple times within the lineage.
Gigantism is not a requirement for flightlessness. The kiwi does not exhibit gigantism along with tinamous, even though they co-occur with the moa and rhea that both exhibit gigantism. This could be the result of ancestral flighted birds arrival or because of competitive exclusion.[11] The first flightless bird to arrive in each environment utilized the large flightless herbivore or omnivore niche, forcing the later arrivals to remain smaller. In environments where flightless birds are not present, it is possible that after the K/T Boundary there were no niches for them to fill. They were pushed out by other herbivorous mammals.[8]
New Zealand has more species of flightless birds (including the kiwis, several species of penguins, and the takahe) than any other country. One reason is that until the arrival of humans roughly a thousand years ago, there were no large land predators in New Zealand; the main predators of flightless birds were larger birds.[12]
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