Each year the RSPB ask people of the UK to pick one hour over the weekend of 30-31st of January and record the highest number of each type of birds they see at any one time in their garden (or in their allotment of course). It doesn't includes birds flying over. By doing this every year the RSPB get a great snapshot of the state of the UK's bird population, what's doing well and what is struggling. If you need any help identifying the birds the RSPB site has a useful tool to help.
At the end of the hour just go online and submit your answers