Swallows are evolving to avoid cars and trucks, study finds
Monday 18 March 2013
Collisions with road vehicles are driving a population of swallows to evolve into faster, more agile fliers with shortened wings.
Natural selection has favoured birds that are better able to get out of the way of oncoming cars and trucks, scientists in the US have discovered.
Survivors tend to have shorter wings that make it easier to take off quickly and pivot out of the path of danger. As a result, the birds’ wings have reduced in length by as much as 4mm over the past 30 years, the researchers found.
This, in turn, has led to a sharp reduction in the number of swallows killed on the roads in Keith County, Nebraska, where the study was conducted.
The findings are an example of how urban environments can become evolutionary hotspots, according to the lead scientist Dr Charles Brown, of the University of Tulsa in Oklahoma.
“Evolution is an ongoing process, and all this – roads, SUVs, and all – is part of nature or ‘the wild’; they exert selection pressures in a way we don’t usually think about,” Dr Brown said. “Longer-winged swallows sitting on a road probably can’t take off as quickly, or gain altitude as quickly, as shorter-winged birds, and thus the former are more likely to collide with an oncoming vehicle.”
The study, published in the journal Current Biology, began in 1982 with researchers scouring the roads for dead cliff swallows, which attach their mud nests on vertical walls under bridges and overpasses. Monitoring the road kill every year showed a dramatic reduction in deaths due to collisions between 1983 and 2012.
Greenpeace comes to the aid of Britain's small fishing vessels
Frilled shark: Australian fishermen capture terrifying shark from the deep
Snowfalls are now just a thing of the past
Brazil drought: It's a really dry January in the South American country, with rainfall is at its lowest level since 1930
The 10 best folding bikes
- 1 Asteroid narrowly scrapes past Earth: how to watch the closest space rock for decades as it flies by
- 2 Saudi preacher who 'raped and tortured' his five -year-old daughter to death is released after paying 'blood money'
- 3 The enemy within: People who hear voices in their heads are being encouraged to talk back
- 4 British grandmother Lindsay Sandiford faces execution by firing squad in Indonesia
- 5 Watch Richard Dawkins read his own hatemail: 'I hope you do get sodomised by satanic monkeys in hell'
'We would evict Queen from Buckingham Palace and allocate her council house,' say Greens
French court convicts three over homophobic tweets, in case hailed as a 'significant victory' by LGBT rights campaigners
Greece elections: Syriza and EU on collision course after election win for left-wing party
British Muslim school children suffering a backlash of abuse following Paris attacks
Islamic history is full of free thinkers - but recent attempts to suppress critical thought are verging on the absurd
30,000 reasons why the rhetoric on immigrants claiming benefits can stop now
£38000 - £42000 per annum: Recruitment Genius: One of the UK's best performing...
£35000 - £43000 per annum: Recruitment Genius: Our award-winning client is one...
£15000 - £21000 per annum: Recruitment Genius: This leading provider of Atlas ...
£18000 - £20000 per annum: Recruitment Genius: Opportunity to join established...