The past week has seen some more subtle changes of season. The warblers are slowly thinning out in number while the overhead passage is just starting to commence. The overhead passage has mainly consisted of the first trickle of siskins and meadow pipits, this will increase over the coming month.

The classic species have been showing well for the past week, just yesterday a bittern was showing very well from reception (a quick snap of the bird trying to blend in can be seen above), with another two seen flying at Tower Hide. Kingfishers have also been very evident from all parts of the fen, it would appear as though another brood has fledged. Two birds were present from reception yesterday with a further two at Tower Hide, with some visitors reporting up to four at once. Bearded tits are gathering now, with a flock of up to 40 birds present in the reedbed, at present they are roaming across the whole reedbed. The best area to see them is between Fen Hide and the riverbank, where very good views can be gained on calm sunny mornings.

The swallows, house and sand martins are lowing in number now, however when conditions are right, much like Saturday afternoon, up to 100 swallows and 50 house martins were seen over the fen and it appeared that a big movement south was occurring.

The woodland and scrubby areas are starting to show signs of autumn, by this I mean that the elder bushes are feeding migrant blackcaps, the fir trees are attracting many goldcrests and the tit flocks are building in number, with long tailed tits attracting blue, great, coal and marsh tits along with nuthatch and treecreepers in tow too.

Unfortunately the otters on the reserve are still keeping a relatively low profile with individuals being seen weekly but not particularly regularly. One of our regular photographers got some lovely shots of a young otter sunbathing on the path, so they are out there to be found.

Perhaps the most surprising sighting of last week came in the form of two swallowtail butterflies. The warm sun on Thursday and Friday must have triggered a mini emergence, one butterfly was seen from Tower Hide, while another was seen along the riverbank. These are unusual sightings as it is so late in the year so it will be interesting to see if they get seen again in the next period of warm weather.

The willow emerald damselflies are still currently on the wing with up to 15 being seen in the viewpoints between the railway and the fen boardwalk and another smaller population is using the newly dug pond between sandy wall and the meadows. Other dragonflies still very much in evidence are brown hawker, southern hawker and many migrant hawkers.

This week I hope to see the bearded tits become a more regular fixture along sandy wall and with the predicted rain in the mornings we may see small falls of warblers in the bushes feeding on fresh berries, meadow pipits should also increase as should flyover siskins with the outside chance of a crossbill or two.