Gazing out across the Basin with binoculars often prompts people to ask "What are you looking at?" and you reply "Well, there are 10,000 birds out there and I am just checking for anything unusual". The expression on their faces is usually a mixture of disbelief ("this guy is pulling my leg") and amazement ("but I can't see anything"). The fundamental tenet of birdwatching is "The more you look; the more you see".
This is exemplified by my garden which contains several feeding, drinking and bathing stations for birds. We monitor the birds regularly and 99% of the time see just the usual garden species, but are rewarded by the other 1% of the time when we spot a stranger. This week two tree sparrows appeared at the seed feeder for the first time ever amongst the more usual house sparrows. This prompts the question "Why have they not come before?"
Compare this situation with the Wildlife Centre, where 5 years ago, house sparrows were very rare and tree sparrows were regular visitors. Nowadays, the situation is reversed, as groups of house sparrows appear every day and tree sparrows are virtually never seen.
So what is going on?
The Wildlife Centre Winter Garden Bird Survey shows that 30 of the 31 gardens surveyed last year were visited by house sparrows while only 7 were visited by tree sparrows. The house sparrow dropped from 4th to 8th in the ranking of most seen bird between 2001 and 2004. In that same period tree sparrows moved up from 32nd to 25th. This suggests that house sparrows are declining while tree sparrows are increasing
The national picture shows something different. Since the 1970's house sparrow numbers have dropped from 12,000,000 to around 3,000,000 and tree sparrows have dropped from 8,000,000 to 200,000. In some areas (London for instance) the loss has been even more dramatic with over 90% of house sparrows gone. This dramatic decline has put both species on the Red List of birds in danger.
The current thinking is that both sparrows are suffering from a lack of insects to feed their chicks during the summer and a lack of seed to feed on during the winter. So the appearance of tree sparrows in more gardens probably indicates a desperate search for food outside normal foraging areas.
Things look bleak for the two sparrows but there are things we can do to help. Providing food and water in our gardens is an obvious move, and clearly, if tree sparrows can make use of that supply, like the two in my garden, then all the better. We can also put up nest boxes to provide them with somewhere secure to raise their young. House sparrows, especially, like to nest in groups, so you can get special nest boxes that have 3 or 4 spaces in one to create a "sparrow terrace".
The Wildlife Centre has a supply of bird food and nest boxes in the shop and plenty of books to help you identify the birds in your garden.
All of us can help to track population changes by taking part in garden bird surveys. Simply by recording the birds we see in our gardens or nearby green spaces can help to build up a picture of bird populations. The Wildlife Centre survey runs from October to March and forms can be obtained from the Centre. The RSPB runs a Garden Birdwatch at different times in the year. Details can be found on the RSPB website (www.rspb.org.uk) and the results can be seen there as well.