We must protect our bird populations from the damaging effects of roads

7 July 2020 

Over the past few months, as an avid birdwatcher and citizen scientist, I have recorded a plethora of bird species on my daily walks, partly thanks to the absence of noise pollution from cars. 

Indeed, birdsong has been one of the few pleasures afforded to many of us during the Covid-19 pandemic. 

For many people, lockdown has instilled a renewed sense of appreciation for nature and all the delights it has to offer. What we, as a society, choose to do with this awareness, is up to us.

We already know the devastating effects noise pollution has on a wide range of species, including our own. Roads, as a major source of noise, air and light pollution, affect populations of many species, including birds.  

A study published this week in Nature Communications by Sophia Cooke and co-authors reports that, in Great Britain, more common bird species, such as woodpigeons, rooks, blackbirds and robins, are associated with greater exposure to roads.

However, rarer and smaller migrant bird species, such as meadow pipits, chiffchaffs and lapwings, decrease in abundance when exposure to road networks increases. 

In other words, roads seem to be creating environmental conditions that benefit more common species at the expense of other, rarer species. Ultimately, this and other human-induced factors could lead to a large scale drop in diversity of bird communities. 

Noise from roads disturbs birds’ communication, making them less able to detect predators and prey, explained Ms. Cooke. 

“In terms of mitigation, tackling noise is going to be one of the most important things. Most of the noise from roads comes from the interaction between the tire and the road surface and not from the engines, particularly at higher speeds,” Ms. Cooke said, noting that measures to reduce this noise will be “particularly important”, one of which is the addition of rubber to road surfaces. 

A barn owl perched atop a post photo: British Wildlife Centre

These findings should act as stark warning signs for Ireland, where bird populations, including lapwings and curlews, are declining at alarming rates. Ireland’s barn owl population, which has been declining for the last 40 years, is particularly vulnerable to the proximity to roads. 

For these birds, the main negative effects of roads seem to be direct mortality through vehicle collisions, rather than disturbance or reduction of breeding habitat. Indeed, this iconic bird’s low flight and hunting behaviour, and poor peripheral vision, make it suffer the effects of traffic while hunting close to road verges. 

Vehicle collisions result in an estimated 50-60 barn owl deaths each year per 100 kilometres on major roads, according to recent research by BirdWatch Ireland and Transport Infrastructure Ireland on sections of the M8 Motorway and Tralee Bypass. 

These estimates are comparable to other European figures, which is concerning given Ireland’s relatively small barn owl population, says John Lusby, raptor conservation officer at BirdWatch Ireland, writing in Birdwatch Ireland’s magazine Wings

Plenty can be done to reduce the risk of collision, from identifying high risk areas on new roads, to enhancing the quality of habitats in the landscape surrounding roads, to inserting screens of trees and wood to deter the birds away from high-risk road sections. 

The formation of a new government brings with it the chance to act to protect our natural capital. But, when it comes to conservation, we are lagging behind. 

Just last week, Ireland has been referred to the European Court of Justice over its failure to designate special areas of conservation, more than five years after the deadline for doing so expired. Ireland has failed to establish conservation measures for a staggering 423 areas. Out of these, 154 areas have not yet been designated as special areas of conservation. 

Senator Pippa Hackett and Deputy Malcolm Noonan have recently been appointed as Minister for Land Use and Biodiversity and Minister of State for Heritage and Electoral Reform respectively. They must now ensure conservation measures are adopted for all environmentally sensitive areas and we, as citizens, must hold our new government to account. 

Studies such as the ones above highlight that a greater focus on mitigating the impacts of roads on wildlife will be important for biodiversity in the future, alongside better planning and development regulations. 

We must not allow our new ministers to fall prey to the ‘Build, build, build‘ rhetoric recently exploited by our nearest neighbour’s leader, much to the detriment of local wildlife. 

According to the UN’s environment chief, Inger Andersen, the Covid-19 pandemic, coupled with the climate crisis, are nature’s way of sending a stark ‘message’ to humanity. If we continue with business as usual, we risk creating an impoverished world, highly vulnerable to future pandemics, which, this time, will not bring with them the solace of bird song. 

Anthea Lacchia is a freelance science journalist and postdoctoral researcher in UCD in geoscience. Her writing has appeared in The Guardian, Nature Index, RTE’s Brainstorm and Science Spin Magazine.