The osprey has become something of enigma in Dorset! Once seen only as a passage migrant in spring and autumn a few years back (possibly c2014?) one bird stayed for the entire summer. Probably a young bird it set up home in Poole harbour but was never joined by a mate and so despite there being some anticipation there was no successful breeding. It seems that every summer since then there has been at least one in the harbour over the summer months but, despite the nesting platform put up at Arne for them, there is still no sign of a positive breeding outcome.
Poole harbour is undoubtedly prime habitat for ospreys with a large expanse of not over deep water with lots of fish, mainly mullet, and plenty of suitable perches and potential nest sites to be had along the southern and western flanks of the harbour and there is no doubt that ospreys like the look of it and yet none have taken the plunge and tried to raise young in the locality. That may be about to change, however, with the top brains in the field working on an introduction system of releasing young fledglings into the harbour in the hope that they will consider it 'home' and return to nest here in a year or so's time. Another site for ospreys in England would certainly be welcome and we can only wait in anticipation and hope that the scheme is successful.
As it stands ospreys can be seen on spring migration in Dorset from about week 12 (early April) through until the end of May during which time they may be seen anywhere along the coast as they arrive and carry on north towards the established nesting grounds in Wales, Rutland Water, northern England and in Scotland. They tend not to dwell here for too long as they have other things on their mind! On the return south they are more inclined to stick around and can be seen from late August and particularly in September but they are usually all gone by week 42 at the end of October. In between these migratory periods then there is now every chance of seeing one in summer around Poole harbour.
The distribution map shows how widely spread sightings are from around the county but, as mentioned above, many of these are casual migratory records, the vast majority of sightings are from Poole Harbour.
If you are setting out with the intention of seeing an osprey as your main objective then head for the RSPB reserve at Arne in September and take the raptor trail to the hide by the nesting platform. Take your lunch and be prepared to wait but there is every chance you will be rewarded with the best osprey action in the south of England!