In this task, you are given a text of many news articles seperated by special token "|||||". Your task is to summarize them.
Q: Oldest yew tree switches sex 
  
 The Fortingall Yew in Perthshire is a tree of international renown as potentially the oldest individual tree in Europe. It has been suggested that it could be as much as 5,000 years old, but this is not universally accepted and needs some qualification. For a start this is an estimate based on a girth measurement of 56 feet by Thomas Pennent in 1769. In old yews the definitive evidence in the form of annual growth rings has long since rotted away. The word ‘individual’ becomes important in qualifying this assertion as we now know certain trees clone themselves and can greatly exceed 5,000 years. Nevertheless, it is still a remarkable thought that this invidual yew tree could have been growing before the Great Pyramid of Giza or Stonehenge were even begun. 
  
 The first thing visitors notice about this ancient tree is that it is surrounded by a small enclosure built of stone with sections of iron railings giving glimpses of the ancient hulk within. The whole experience is reminiscent of a trip to the zoo. This unfortunate state of affairs came about as a way of putting off unscrupulous souvenir hunters who would help themselves to parts of the tree. 
  
 Closer examination reveales the Fortingall Yew is a male tree. Yews are normally either male or female and in autumn and winter sexing yews is generally easy. Males have small spherical structures that release clouds of pollen when they mature. Females hold bright red berries from autumn into winter. It was, therefore, quite a surprise to me to find a group of three ripe red berries on the Fortingal yew this October when the rest of the tree was clearly male. Odd as it may seem, yews, and many other conifers that have separate sexes, have been observed to switch sex. Normally this switch occurs on part of the crown rather than the entire tree changing sex. In the Fortingall Yew it seems that one small branch in the outer part of the crown has switched and now behaves as female. 
  
 Three seeds have been collected and will be included in an ambitious project to conserve the genetic diversity of yew trees across their geographic range including Europe, the Caucasus, Western Asia and North Africa. The project will see the exisitng perimeter hedges at the Botanics replaced by a conservation yew hedge grown from cuttings and seed collections made from wild populations and significant ancient trees like the Fortingall Yew. The first phases of planting went in the ground in 2014 and on completion the hedge will encircle the Garden with a remarkable genetic resource of over 2,000 individual trees, each of which will have a story and can be traced back to their origins in Britain or beyond. This hedge could well be the largest conservation hedge of its kind anywhere in the world. 
  
 As it matures the hedge will display a range of characteristics reflecting the genetic diversity of the many individual trees involved and as such it will not look like any existing yew hedge. The Fortingall Yew itself will be represented in the hedge and so too, all being well, will its offspring via the curious ability of yew trees to change sex. ||||| AFP / Karen Bleier 
  
 Botanists believe a delicate shift in the balance of hormone-like compounds can cause trees to change sex 
  
 A British tree thought to be up to 5,000-years-old has started to change sex, a "rare and unusual" phenomenon not fully understood by scientists, a botanist said Monday. 
  
 The Fortingall Yew, in Perthshire, central Scotland has for hundreds of years been recorded as male, but has recently begun sprouting berries, suggesting that at least part of the tree is changing gender. 
  
 "It's a rare occurence ... rare and unusual and not fully understood," said Max Coleman of Royal Botanic Garden Edinburgh, who spotted the berries. 
  
 "It's thought that there's a shift in the balance of hormone-like compounds that will cause this sex-change. One of the things that might be triggering it is environmental stress." 
  
 However, the tree appears healthy, Coleman said, adding that it would now be closely observed for further changes. 
  
 The gnarled tree is situated in an old church yard, and is difficult to age because its heartwood -- the wood in the centre of the tree -- has long rotted away. 
  
 Scientists have been able to estimate by comparing its current size with measurements taken in the 1700s. ||||| Image copyright Mogens Engelund Image caption The tree has been calculated to be anywhere from 2,000 to 5,000 years old 
  
 A Perthshire yew tree, believed to be one of the oldest in Europe, has started changing sex. 
  
 The Fortingall Yew, reputed to be up to 5,000 years old, has started sprouting berries on one of its upper branches - something only female trees do. 
  
 Scientists at the Royal Botanic Garden in Edinburgh, said it was "quite a surprise" to find berries on the tree, in the churchyard of Fortingall. 
  
 The berries have been collected for protection and to be studied. 
  
 Their seeds will be included in a project to conserve the genetic diversity of yew trees around the world. 
  
 The tree is said to be one of the oldest living organisms in Europe - according to local legend, Roman prefect Pontius Pilate was born in its shadow. 
  
 'Quite a surprise' 
  
 Dr Max Coleman, a science communicator at the Royal Botanic Garden Edinburgh, discovered the berries on the tree. 
  
 He said: "Yews are normally either male or female and in autumn and winter sexing yews is generally easy. 
  
 "Males have small spherical structures that release clouds of pollen when they mature. Females hold bright red berries from autumn into winter. 
  
 "It was, therefore, quite a surprise to me to find a group of three ripe red berries on the Fortingall Yew when the rest of the tree was clearly male." 
  
 Image copyright SALTIRE NEWS Image caption Dr Coleman said it was quite a surprise" to find the berries on the normally male tree 
  
 He added: "Odd as it may seem, yews, and many other conifers that have separate sexes, have been observed to switch sex. It's not fully understood - normally the switch occurs on part of the crown rather than the entire tree changing sex. 
  
 "In the Fortingall Yew it seems that one small branch in the outer part of the crown has switched and now behaves as female." 
  
 It is difficult to calculate the age of ancient yews, as their annual growth rings rot away. 
  
 A girth measurement in 1769 suggested the Fortingall Yew could be up to 5,000 years old, although more recent estimates suggest between 2,000 and 3,000 years. |||||
A: 
One of Europe's oldest surviving organisms is having a "sex change"—and growing pretty red berries to boot. A yew tree in Scotland that's thousands of years old has grown three seed-bearing berries, marking it as "female" for the first time on record, the Guardian reports. "Yews are normally either male or female and in autumn and winter sexing yews is generally easy," writes botanist Max Coleman in a blog for the Royal Botanic Garden Edinburgh, where the Fortingall Yew lives in a stone enclosure. "Males have small spherical structures that release clouds of pollen when they mature. Females hold bright red berries from autumn into winter." He says it was "quite a surprise to me" to discover the berries, each of which contains a single seed. Turns out it's not that strange: Yews and other conifers are known to change sex "on part of the crown," explains Coleman. "In the Fortingall Yew it seems that one small branch in the outer part of the crown" has changed after the tree was male "for hundreds of years." So why the switch? It's usually caused by "a shift in the balance of hormone-like compounds," he tells AFP, but "one of the things that might be triggering it is environmental stress." Now botanists have sown the three seeds in the botanic garden to preserve the genetic diversity of yew trees. As for the Fortingall Yew, it's hard to date exactly because its growth rings have rotted, but estimates put it between 2,000 and 5,000 years old, the BBC reports. It lives behind an enclosure to prevent "souvenir hunters" from "help[ing] themselves to parts of the tree," writes Coleman.