Where would you go to bask in nature课件

1、Where would you go to find the most colourful wildlife?庞羽旋201528000206050n Where would you go to bask（晒太阳） in natures most dazzling（耀眼的） colours?n Many of us would head for the tropics（热带地区）. Since the 1800s, explorers have waxed lyrical about（津津乐道于） the dazzling colours of tropical wildlife. From p

2、arrots and butterflies to orchids and birds-of-paradise（天堂）, tropical animals display bold（大胆的） tapestries（挂毯上） of turquoise（绿松石） on red or blue on orange: an extreme richness of colour, according to the naturalist Alfred Russel Wallace.n But we might be wrong about this. A new study flies in the fa

3、ce of popular belief and concludes that temperate（温带） wildlife is more colourful than tropical.A rainbow lorikeet (Trichoglossus haematodus), Queensland (Credit: Konrad Wothe/NPL)nRhiannon Dalrymple compared the colours of different groups of wildlife during her PhD at the University of New South Wa

4、les in Sydney, Australia. She has since moved to Hamline University in Saint Paul, Minnesota.nWhen we started, I thought I would just be proving an old idea, says Dalrymple.nEarlier studies were contradictory（矛盾）, but each study only tested a narrow set of wildlife and only looked at colours that hu

5、mans see.A common green birdwing (Ornithoptera priamus), Queensland (Credit: Konrad Wothe/NPL)n Dalrymple and her colleagues compiled a list of 1,333 species of native birds, butterflies and flowers along the eastern coast of Australia, down as far as Tasmania. Their sample spans 34.5 of latitude（维度

6、） and includes tropical rainforests, temperate woodlands and shrublands（灌木丛）.n They recorded their colours of all the species, including ultraviolet light（紫外光）, and noted where they lived. Then they checked whether the colours were more intense（强烈的） in the tropical regions, if they were more contras

7、ting, or if there was a greater range of colours on display.Red-eyed tree frogs (Agalychnis callidryas) are tropical (Credit: Phil Savoie/NPL)n They found that colouration（对比） hardly changed at all from north to south.Both Dalrymple and Adams had to use museum collections to get enough specimens n B

8、ut there was weak evidence that wildlife further away from the tropics sported more colours, and that the colours were also more intense with bigger contrasts.n The result have been published in the journal Global Ecology and Biogeography.n We have flipped peoples views, says Dalrymple.n Not everyon

9、e is convinced. The study is focused on eastern Australia, and it is a big jump to assume that the patterns there apply to the rest of the world, says Jonathan Adams of Seoul National University in South Korea.A greater bird-of-paradise (Paradisaea apoda) displaying, Indonesia (Credit: Tim Laman/Nat

10、ional Geographic Creative)n In a study published in 2014, Adams examined 247 butterfly species and found that those in tropical Ecuador were more colourful than those in subtropical Florida and temperate Maine. He says that his study covered both ever-wet tropics and more severe temperate climates,

11、whereas Dalrymples Australian study only touches mild winters and the fringes of subtropics.Adams says he wants to keep an open mindn Both Dalrymple and Adams had to use museum collections to get enough specimens for their studies. But those collections might be biased towards more colourful organis

12、ms.n Thats because many came from professional collectors who made a living selling their specimens, and these collectors tended to ship more colourful specimens than drab ones. Thats understandable: a jambu fruit dove, with its plum-red head and jade-green plumage, brightens up a room more than a brownish-grey zebra dove.n Biases in collections could