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Garden Birds and Pesticides

February 6, 2023

University of Sussex researchers find pesticide use is linked to garden bird decline: Gardeners can help save British songbirds from extinction by stopping pesticide use

  • House sparrows (down 70% since the 1970s) are especially affected by herbicides containing glyphosate
  • Great tits, robins, chaffinches, dunnocks affected by pesticides in rural and urban gardens
  • SongBird Survival charity supported the study, has 5 tips for bird-loving gardeners 

 “Avoiding the use of pesticides really makes a measurable difference to the number of birds you will see in your garden.” Cannelle Tassin de Montaigu PhD study author

Pesticide use by British gardeners is playing a significant role in the populations of our songbirds, as shown by the first study of its kind, published today in ​​Science Of The Total Environment. The study conducted by researchers at the University of Sussex shows that gardeners who use pesticides can expect to see fewer birds, especially house sparrows, whose numbers were 25% lower in gardens where commonly-available glyphosate was used (known by their brand names such as Roundup or Gallup) However, the research confirms positive news that providing bird-friendly habitats in gardens increased the number of species recorded, and the abundance of individual species.

The study, supported by, SongBird Survival, drew on data gathered by the British Trust for Ornithology which organises Garden BirdWatch - a citizen science garden bird recording scheme. It examined information on pesticide use and garden management from 615 garden owners. The owners recorded which brands or products they used, revealing that 32% of gardens used pesticides, and that glyphosate-based herbicides made up over half of those applications (53%). In gardens where metaldehyde slug pellets were used, house sparrow numbers were down by almost 40%. (Whilst this chemical was banned in 2022, it is likely to exist in garden sheds, and in the environment, for some time.)

Professor of Biology at the University of Sussex, Dave Goulson, known for his work on bee ecology and insect-friendly gardening, supervised the research. Professor Goulson explains: “The UK has 22 million gardens, which collectively could be a fantastic refuge for wildlife, but not if they are overly tidy and sprayed with poisons. We just don’t need pesticides in our gardens. Many towns around the world are now pesticide free. We should simply ban use of these poisons in urban areas, following the example of France.” 

Author of the study, Cannelle Tassin de Montaigu PhD, says: “It’s encouraging to find that simple measures, such as planting native shrubs and trees and creating a pond, together with avoiding the use of pesticides, really makes a measurable difference to the number of birds you will see in your garden.” 

SongBird Survival funds high quality science to better understand why Britain’s Songbird numbers have fallen by around 50% in 50 years. As birds rely on the entire food chain for survival, gardeners concerned with biodiversity loss should rethink their use of pesticides and increase bird-friendly habitats in their gardens via the tips below. 

Susan Morgan (biography), the charity’s CEO, adds: “We’re still trying to understand the factors behind the tragic loss of British songbirds, so we are delighted this new study by Sussex University sheds light on why, and how we can help. Brits love their gardens, and as a nation of bird lovers, we must ‘think biodiversity’ and do our bit: Avoid using toxic chemicals or else we’ll continue to see house sparrows, robins, tits and other small birds continue to disappear, their songs silenced forever.”

Bird exposure to harmful pesticides comes in both direct and indirect forms, whether through consumption of contaminated food and/or water, absorbing pesticides through the skin or through a decline in numbers of their insect prey. Norwich-based entomologist, Ian Bedford, gives talks on how gardeners can support insects in environment-friendly ways. He says, “A common question I’m asked by gardeners at this time of year is, ‘How can we control plant pests such as aphids and vine weevils without using toxic pesticides in our gardens?’  The answer is to try using environmentally friendly products instead, that deter or block plant pests from susceptible plants instead of killing them.  And this will be important if we are going to use our gardens to help restore Britain’s rapidly declining biodiversity, since the creatures we call ‘the plant pests’ are also an essential food source for many other wildlife.  Nowadays, there are many non-toxic products that could be used as an alternative to chemicals, so I would certainly encourage Garden retailers to stock a selection of these in their stores and make a real difference in the choices gardeners make.”


  1. Ditch the pesticides! The study found that using pesticides is associated with ~12% lower house sparrow abundance. 
  2. Plant berry bushes to provide natural food and shelter, increasing garden ‘quality’.
  3. Have a water source in your garden e.g. bird bath or a pond (which encourages invertebrates).
  4. Hedges made up of different species which flower at different times of the year provide year-round food and shelter for our songbirds e.g. brambles, hazel, honeysuckle
  5. Plant flowers that encourage insect life and songbirds e.g. sunflowers, jasmine, fennel, teasel.


  • Overall, the UK breeding bird population has fallen by 19 million breeding birds since the late 1960s.
  • House sparrow populations have fallen by 70% since the 1970s, with the loss of 10.7 million pairs.
  • Gardens cover an area of about 400,000 ha, bigger than all of our National Parks.
  • Pesticide Action Network’s ‘Pesticide-Free Towns’ campaign:
  • Infographic above is available here.  


  • Professor Dave Goulson, University of Sussex
  • Cannelle Tassin de Montaigu, University of Sussex 
  • Susan Morgan, CEO, SongBird Survival
  • Charlotte Bartleet-Cross, Songbird Survival
  • Ian Bedford, Entomologist and Nature-friendly Gardening Expert 


For all enquiries, including interview requests and hi-res images, please contact:-

Sussex University
Press Office: Lauren Ellis, E:  T: 07587 063573

SongBird Survival / Ian Bedford:
Hannah Kapff:  E: 

T: 020 3397 9111 or M +44 (0)7747 794306  or Sophie Wesley: T: 020 3397 9111 or M +44 (0)7880 290702 |


SongBird Survival is the only charity in the UK solely dedicated to halting the alarming decline of songbirds – birds, such as corn bunting, willow tit, tree & house sparrow. It does so by funding independent scientific studies that aim to shed light on the reasons why around 50% of our songbirds have disappeared over the past 50 years. These studies will help determine how land can be managed more sustainably, with a view to restoring a rich, balanced, thriving and resilient population of birds to keep a healthy dawn chorus alive. @SongBirdSBS | Twitter @SongBirdSBS | Insta @songbirdsurvival

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