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.
Dolphins ‘deliberately get high’ on puffer fish nerve toxins by carefully chewing and passing them around
Iberian lynx cubs born in the wild bring hope for the world's most endangered feline species
Water firms to pipe biomethane gas generated at sewage-treatment works into Britain's homes
Morne Hardenberg: 'Great white sharks have a softer side most people never get to see'
AeroFarms: Work starts to build world's largest vertical urban farm in Newark
- 1 If I were Prime Minister: I'd give tax cuts to the rich, keep Trident, and get my football team wrong
- 2 Italian police 'reveal' what Jesus looked like as a young boy
- 3 General Election 2015: 14-year-old boy asks Nick Clegg – 'can you kill Katie Hopkins?'
- 4 University student in court for allegedly covering housemates' food in window cleaner and spit
- 5 Ryan Gosling posts tribute to 'Ryan Gosling Won't Eat His Cereal' creator Ryan McHenry
In defence of liberal democracy
Over 50,000 families shipped out of London boroughs in the past three years due to welfare cuts and soaring rents
EU asylum policy is 'a direct threat to our civilisation', says Nigel Farage
The Rothschild Libel: Why has it taken 200 years for an anti-Semitic slur that emerged from the Battle of Waterloo to be dismissed?
General Election 2015: UK will be 'run for the wealthy and powerful' if Tories retain power, Labour warns
General election live: SNP suspends two members for disrupting Labour rally
£13676.46 - £16411.61 per annum + OTE: SThree: SThree Trainee Recruitment Cons...
£18000 - £22000 per annum + training: Ashdown Group: Business and Marketing Gr...
£20000 - £25000 per annum + Commission: SThree: Are you great at building rela...
£20000 - £22000 per annum + excellent benefits: Ashdown Group: Application Sup...