Sinking in the cities

UK Priority Species: House sparrow

There are records of house sparrows from before the Stone age, they were used in Ancient Egyptian hieroglyphs, they were sacred to Aphrodite and her roman equivalent Venus and they were even included in some particularly fine Elizabethan recipes. Infamous throughout history, and across the globe, the house sparrow has had a big impact on human cultures everywhere, as the most widely dispersed wild bird in the world. They have followed humans out to sea on our boats, they have lived on the upper floors of the empire states building, and even bred down a 2000ft mine shaft, all in order to capitalize on their close ecological relationship with humans. Therefore, you would think, surely a booming human population could only mean good things for house sparrow populations? 

The secrets of spaggers (one of the colloquial names for sparrows)…
The gregarious house sparrow is perhaps the ultimate opportunitst, exploiting humans and our waste, for food and novel housing. Often seen roaming in gangs, these noisy, cheerful and quick-witted birds have been reported opening automatic doors to enter supermarkets! It would not seem possible that these extravert birds would have anything to hide…

Interestingly, due to the public nature of their copulation, sparrows have long had associations with sex. Shakespeare famously referred to their lecherous personality in several of his works. However, the sexual behaviour of the house sparrow is actually far more intriguing. Work undertaken by Denis Summers-Smith, a world expert on sparrows, found that from visual recording, it appeared most sparrow mating occurred between established couples. However, results from DNA analysis showed, that 15% of offspring were the result of copulations with different partners. Therefore, it appears that sparrows carry out these illicit unions in secret.

From pests to pies
Historically, house sparrows have been viewed as pests and nuisances. In the early 20th century, we were harvesting millions of birds and tens of thousands of eggs because they were considered an agricultural pest. Harvesting even became a sporting competition, with the record for the highest level of harvesting being over 4,500 birds for one person. Birds were netted, shot, eggs were collected, nests destroyed, and some birds were even eaten in pies. It seems incredible that despite this level of harvesting, the population was hardly affected and this provides a shocking comparison to the plight this species faces today.

Despite being protected by legislation, recognized as civilians of our towns, and being loved and fed by many members of the public, the greatest decline in house sparrow numbers has occurred in the last 2 decades. There are amazing tales of sparrow flocks, which included many thousands of individuals, and this makes me very envious. I was delighted a few weeks ago to see a group of 9 young sparrows, all sitting together in a long line on a willow branch, happily singing and looking very comical. Hearing of their comparative historical abundance is extremely sad and rather terrifying. And, as Mark Avery, the director of conservation for the RSPB has said "When even the common sparrow is declining, it shows the world is in a bad state."

So then, just how common is the world-renowned house sparrow in 2010, the international year of biodiversity?
Once with a population of over 25 million breeding birds, they were the commonest breeding bird in the UK, but now they’re struggling just to survive. House sparrows have clearly declined in both gardens and the wider countryside and their recent declines have been enough to earn them a place on the Red List. Numbers have dropped nationally over the last 25 years, and in London they declined by 66 % between 1995 and 2007, according to the Breeding Bird Survey. Sparrows are now absent from many areas of central London where they were once common. Populations have declined most in eastern England, which has seen a 90% decline since 1970.

Bird monitoring often provides an indication of the health of an ecosystem. With 90% decline in some areas, what does this say about the quality and health of the environments in which we live?

Where’s me spaggers?
Recent research has been undertaken by the RSPB and De Montfort University to identify which environmental factors (food, predators, competitors etc) are likely to have caused the decline of house sparrow populations in towns and cities. Research has shown that house sparrows in urban areas suffer during the breeding season from a lack of insects to feed their young. This leads to poor condition and death of young chicks.

What is the RSPB doing for house sparrows?
A large scale feeding experiment in London has demonstrated that insects are important for the survival of young chicks. Through a new London project, we hope to find more natural ways to increase the numbers of insects available to sparrows and other birds in our urban green spaces. The London House Sparrow Parks Project is trialling different habitat management types in London parks with the aim of boosting invertebrate numbers. The habitat plots should also provide seed during the winter, and could benefit a host of urban birds, insects and other wildlife.

The project aims to test whether long grass, native wildflower meadows or wildlife seed plots benefit house sparrows and other species the most. This will enable us to provide advice to green space managers across the country on positive management for those much loved, familiar birds that rely so much on sharing a healthy environment with people. There are currently 27 plots across London trialling these different management solutions.

What you can do to make a difference in the International Year of Biodiversity!
· There are many problems facing our urban wildlife, and you can make a huge difference to helping with the solutions. The power is in your hands! We need greener and healthier urban spaces. Gardens offer incredible oases for wildlife and there are really simple things you can do to make these spaces more suitable. Find out on our Homes for wildlife pages for some creative ideas. Also there is a cool blog on Gardening for wildlife which has good advice for all types of gardens.
· If you think living in the big smoke means you have to travel to find your space in nature think again. There are many interesting species associated with the built environment. Two-thirds of London consists of green space and water, making it the world’s greenest city. It is home to more than two hundred different bird species including magnificent peregrines and humble sparrows.  Check out our Greater London pages to find out what’s going on.