The 2017 Big Garden Birdwatch was held at the beginning of this month. This annual survey gives a snapshot of our garden bird population and an idea of which species are doing well. This huge annual citizen science event allows scientists to tap the vast resources of an interested public, by asking them to act as the observers of nature. It also provides a critical evidence base of the changing health of the environment by monitoring numbers and distribution of previously common species.
The house sparrow (Passer domesticus) is a real city bird, living in close proximity to humans and exploiting our buildings for their nest sites. House sparrows are noisy, social and are what people think of as the typical British “small brown bird.” These small birds have a big personality and, for many people, are the closest they come to “nature” in their urban environment.
Popularity does not however protect the species. For a species which was so abundant that rewards were paid for killing them in the 18th to 19th century, the house sparrow is now Red listed in the Birds of Conservation Concern (Eaton et al. 2015) – population numbers declined nationally by 71% between 1977-2008 in both rural and urban habitats. The decline is evident in Bristol too.
Having once been abundant throughout the city, their distribution is now largely focussed on the suburbs and outskirts.
There are numerous causes of decline. Many nest sites are lost to house renovation and new build houses are often impregnatable to wildlife. Loss of urban green space, use of herbicides and pesticides, and gardens converted to decking and car parking all reduce the supply of invertebrate prey for house sparrows, which is directly linked to chick survival and fledging rates. Inevitably, high populations of domestic and feral cats also take their toll, as do increasingly high levels of pollution.
In rural areas changes in farming practices, such as the loss of over-wintered stubble and improved hygiene around grain stores on farms, is thought to have exacerbated the decline.
Like all wild birds house sparrows are protected under the Wildlife and Countryside Act 1981, which makes it illegal to intentionally kill, injure or take a house sparrow, or to take, damage or destroy an active nest or its contents. This means they should be considered when completing roof or soffit box repairs during the breeding season (March-September).
House sparrows usually nest in close proximity to other pairs, living in colonies, and it is not unusual for them to rear three clutches of chicks over the breeding season. The availability of insect prey is key when rearing chicks but, once they fledge, the youngsters will move to a diet of seeds. They are cared for by the male for about two weeks after leaving the nest, as the female will already be preparing to lay the next brood of eggs.
Can we help this declining species?
A variety of simple garden activities can help the house sparrow.
Give a home
By putting up a nest box you can provide them with a place to raise their chicks and, as they like to nest in close proximity to one another, if you put up several boxes you could create a colony. You can find nest box designs, or buy them ready made, on the RSPB website.
It’s best to fix the nest boxes high up, near the eves of your house (avoid nest site competition between different bird species by siting new boxes away from any existing bird boxes if already used).
Attract insects to your garden
Help the sparrows when they are rearing their chicks, by inviting their insect prey into your garden. This is easily achieved by choosing plants such as apple, oak, birch, willow and alder which provide food for caterpillars and insects. Choose insect attracting seed mixes, which are labelled at the garden centre. Or set aside some of your garden to “go wild” (let the grass grow long and leave it unmanaged, you’ll be surprised at the species it attracts). This type of gardening not only helps sparrows but other wildlife such as hedgehogs, amphibians and bats.
Give extra food
Offering food helps at any time of year, in the winter when food is scarce and in the spring/summer when they are rearing chicks. A seed mix containing sunflower hearts will attract sparrows, with a summer supplement of mealworms helping to raise chicks. It’s best to avoid offering loose peanuts, large chunks of bread or hard/dry food which can choke the chicks.
Good hygiene is critical when feeding garden birds to avoid the spread of any diseases. Make sure you clean the bird table or feeder with a mild disinfectant regularly, and ensure they are dry before replacing the food so it doesn’t go mouldy. Cleaning up under your feeding station will also keep rodents away. Providing a simple water bath will help the sparrows to keep their plumage in good condition, as well as giving somewhere to a drink. Again, this should be regularly cleaned.
If you are lucky enough to already have this species visiting your garden, you’ll know that they are an interesting, lively and boisterous addition to any patch. By following the steps above you could make a real difference to this species’ survival in Bristol, as well as increasing your own enjoyment of your garden, an all-round win!
For more information, please contact Pippa Cope at: Pippa.Cope@thelandmarkpractice.com