One of the reasons why birdwatching is so popular is that it can be enjoyed all year round. There is always something going on throughout the seasons, but for many the special times are the peak periods of the incredible migration movements in spring and autumn.

In earlier years there were a limited number of places in Oxfordshire where birds might settle down for a while on their journeys. Exceptions were the old smelly sewage works at Cowley or Abingdon that brought in several species that sought water and mud habitats. Older birdwatchers recall the odour of these places with nostalgia.

Those attractions have now been removed, but the creation at Farmoor in 1965 of a large reservoir has more than compensated for the loss. Its wide stretch of open water and banks are magnets for a range of species passing over, including some new to the county.

The situation has been further improved by Thames Water creating new reserves near the Thames at Pink Hill and Shrike Meadow that have provided additional attractions for breeding and resting birds. Some 15 years ago the Oxford Ornithological Society, with the kind permission and support of Thames Water, began a series of open days in May and September to show the public the value of Farmoor. More than 70 visitors came on the most recent occasion. It has always been especially rewarding to welcome several family groups including some sharp-eyed youngsters anxious to learn.

The birds on show can never be precisely predicted as various species drop in and out according to the weather, but there are usually surprises. This time incoming swifts arrived on cue, but unexpected were a wood warbler and a redpoll passing through.

In addition, visitors on these occasions have the opportunity to examine ranges of binoculars and telescopes. Look out for dates of the next event in September.