An unexpected visitor

It is now two weeks since we released the first of the Poole ospreys and its been encouraging to see them becoming increasingly competent on the wing. All are now making longer exploratory flights; an essential part of the imprinting process when the birds start to learn that Poole is home.  Most young ospreys do not catch a fish before they set out on their first migration, but Poole Harbour provides the perfect conditions for the young ospreys to practice fishing and several of the birds have already been seen diving into the water.

Last Monday we released the final two birds, LS2 and LS4. Like their older compatriots they did not venture far from the release pens for the first few days after release, but they too are quickly growing in confidence and starting to explore further afield. The frequency and range of exploratory flights will increase over the coming days but all of the birds will return to the release site to feed, particularly in the early morning and evening. The team at Poole will continue to provide fresh fish twice daily on artificial nests; thereby replicating the situation at natural nests, where the male continues to feed his offspring until they depart on migration. This is an essential part of the post-release phase; helping to ensure that the young birds are in the best possible condition for when they set-off on their first migration. In some ways this puts the translocated ospreys at an advantage compared to birds at natural nests, because we can ensure that they receive as much fish as possible before they set-off on migration.

Fresh fish is placed on artificial nests twice daily (photo by Simon Kidner)

On Tuesday afternoon last week the juveniles were joined by an unexpected visitor. During a particularly long soaring flight over the harbour LS1 attracted the attention of an adult female osprey. She followed LS1 back to the release site and then landed on one of the T perches in the saltmarsh adjacent to the release pens. We immediately saw that she had a blue colour ring on her right leg and were able to read the inscription: CJ7. A quick phone call to Kayleigh Brookes confirmed our suspicions that this was a two year-old female ringed as a chick at a nest close to Rutland Water in 2015.

CJ7 appeared over the release site on Tuesday afternoon (photo by Simon Kidner)

After circling the marsh CJ7 attempted to land with two juveniles on one of the T perches (photo by Simon Kidner)

CJ7 (right) eventually landed next to one of the juvs, allowing us to read the inscription in her blue ring (photo by Simon Kidner)

CJ7 (left) spent the rest of the day with the juveniles, some of whom began food begging to her

This was the first time that CJ7 had been seen back in the UK since her first migration in September 2015 and so it was exciting to see her. Although clearly nervous at first, she spent the rest of the afternoon and evening with the juveniles. With food begging calls filling the air (normal behaviour for juvenile birds of this age, even when they are not hungry!) we wondered if the young female may even be persuaded to catch a fish for the translocated birds, as adult birds did at both Rutland Water and Urdaibai in the past. Although she didn’t do that, she did roost with them before heading off to another part of the harbour next morning.

On Saturday morning CJ7 returned again and, like her previous visit, perched with the juveniles on the saltmarsh. The presence of other ospreys in the harbour, and particularly food-begging juveniles, may well persuade CJ7 to stay in the area for longer than she might otherwise have done. We know from colour ringing and satellite tracking studies that two year-old ospreys wander widely when they first return to the UK, helping them to map the location of other nesting ospreys. We hoped that the presence of the translocated birds would act as a magnet to other young ospreys and it is very encouraging that it is happening already. Who knows, CJ7 may even return to breed at Poole Harbour in the future. For now it is just great to see the translocated ospreys exploring Poole for the first time.

If you would like to help us to undertaken more proactive projects like this, why not consider becoming one of our Conservation Champions? You can find out more here. We would greatly appreciate your support.