Populations of some uncommon and small-bodied birds in Britain, such as meadow pipits and lapwings, suffer disproportionately when near a road, a study has found.
Researchers from the University of Cambridge say this may be caused by a dislike of grass verges as they prefer arable land.
Another factor could be heightened sensitivity to road noise and air pollution.
However, common species such as robins, blackbirds and bullfinches benefit from increased asphalt because they don’t mind the raucous.
Grass verges also provide warmth, ample food and habitat for the birds, scientists say.
Conservationists warn that Britain could see a less diverse range of avians as rarer species struggle to cope with Britain’s sprawling road network.
Pictured, a meadow pipit . This species is one of the birds struggling to adapt to encroaching roads. A study found a 31 per cent decrease in abundance of this bird due to increased roads in the UK
Increased asphalt brings with it an increase in verges, which provide heat, food sources and habitat for birds, and some common species ar thriving, such as the Eurasian bullfinch (pictured) which experienced a 28 per cent increase when road exposure was taken into account
‘In general, nationally common species are found in higher relative abundance around roads, while nationally rarer species are found in relatively low abundance around roads,’ said Sophia Cooke at the University of Cambridge.
‘Around roads it isn’t just individual bird populations that differ but entire communities.
‘This could be leading to something called simplification, or homogenisation of bird communities, where although high numbers of some species are maintained, diversity decreases.
‘We see this in urban areas – you aren’t likely to spot many rare species in cities, but you will find lots of pigeons and corvids.’
Britain has one of the densest road networks in the world, with 80 per cent of land found within a kilometre of a road.
In the past 50 years, traffic on British roads has increased by more than 160 per cent and over the same period there have been large declines in many bird species.
As a result, Ms Cooke says it ‘makes sense to question whether there could be a link between the two’.
Using data from the UK Breeding Bird Survey, Cooke and colleagues assessed the abundance of 75 bird species in relation to roads across Britain.
The authors found 58 species affected by the presence of roads, with 33 types of birds being negatively impacted.
A common blackbird. The study suggests that road networks create environmental conditions that benefit common bird species (including rooks, blackbirds and robins) at the expense of others
Northern Lapwing (Vanellus vanellus) immature at the water’s edge in Cley Marshes Nature Reserve, Cley-next-the-Sea, Norfolk, UK August
A stunning male Blackbird (Turdus merula) perched on a fence. The ‘compression’ of vulnerable species into areas of low road density may lead to declines and extinctions in countries with high road densities in the future
As exposure to roads increased, rarer species decreased in numbers. The opposite trend was seen in common species.
For example, the meadow pipit experienced a 31 per cent decrease in abundance, whereas the Eurasian bullfinch experienced a 28 per cent increase when road exposure was taken into account.
The compression of vulnerable species into areas of low road density may lead to declines and extinctions in countries with high road densities in the future, researchers warn.
Cooke said more research is needed on the severity of the effect of roads on species, not just in the UK, but globally.
The Royal Society for the Protection of Birds (RSPB) told MailOnline that the research shows how Britain’s infrastructure network forces nature into ‘smaller and smaller spaces or expecting it to fit in with our needs’.
‘In planning a new road we can look at the loss of habitat and damage to existing wildlife, and assess whether this cost to nature of this is too high before any concrete is poured,’ said an RSPB spokesperson.
‘Once a road is constructed many of us will be familiar with the sad sight of hedgehogs, badgers and other mammals that have been injured or killed by traffic.
‘Smaller animals like birds are less easy to see, which makes this report really valuable in highlighting the impact a new road might have on local wildlife and how we might solve this.’
The study has been published in Nature.
Carrion crow perches on a wooden fence. Species with smaller national populations generally have lower relative abundance with increasing road exposure, whereas the opposite is true for more common species
A tree pipit stands proudly on the trunk of a tree. The study found the meadow pipit experienced a 31 per cent decrease in abundance near roads
Photograph taken off Great Cross Avenue in Blackheath, South East London, in the London Borough of Greenwich. Here we see a European robin (Erithacus rubecula), also known as the Robin,
A Close up of a juvenile Rook (Corvus frugilegus) asking its parent for food. Picture taken in Swindon, Wiltshire, England in June this year
A Skylark (Alauda arvensis) perched on a fence post singing. Picture taken at Swindon, Wiltshire, England in June last year