Archives for February 2018

No new data

During the winter we have received almost daily transmissions from Jules’ satellite transmitter, but no recent data from Blue DF. Analysis of the engineering and diagnostic data from the transmitter indicates that this is due to battery failure. This is extremely frustrating but we are almost certain that the bird is still alive and well in the Casamance region. Chris Wood, Joanna Dailey, Junkung Jadama and Fansu Bojang went to look for him in December. They didn’t see him because access to his favoured daytime area was impossible due to high water levels but they did send these photos. They also saw a flock of close to 100 Black-crowned Cranes. Thanks very much to them all for trying. Like Jules we hope to see Blue DF back in Strathspey this spring. In the meantime we will update you should the transmitter begin sending data again.

Life’s a beach

In our last update on the latest movements of our satellite tagged osprey, Jules – who is wintering in the Casamance region of southern Senegal – we reported that he was dividing his time between favoured daytime perching and fishing spots on the coast and a regular roost site in mangroves 16 km inland. This is quite unusual given that most adult ospreys usually occupy a very small winter territory.

Jules has continued to favour the same stretch of coastline since the turn of the year, but over the past month he has also started roosting on the coast; usually among scattered trees about 800 metres from his favoured stretch of sand. Over the past month he has roosted on the coast more often than inland. Quite what has promoted this change of behaviour is unclear, but by doing so he is avoiding the necessity of a 32 km return flight each night.

Jules has been favouring a 1 km stretch of beach during the past two months.

Other than this change in roosting location, Jules’ behaviour has been much the same as the rest of the winter. He has favoured the same 1 km stretch of beach and continued to fish just offshore once or twice each day. Most of his fishing is done within 200 m of the shore, but on at least two occasions since 1st January he has flown further out to sea (1.5 km or more). When he roosts on the coast he is favouring an area of just over 1 km which is much more typical of the usual winter range of an adult osprey.

Jules’ latest movements – including a flight to the east on 16th February

Interestingly Jules roosted inland on the nights of 15th and 16th February and during the afternoon of 16th February flew 25 km to the east – perhaps flying around with other ospreys – and spent a few hours perched in creeks near Tionck Essil. Next day however he was back at his favoured spots on the coast and he roosted there that night.

Jules is likely to remain in Senegal until mid-late March before beginning his migration back to Strathspey.   You can check out all of his latest movements on our interactive map. Our other satellite tagged osprey, Blue DF is wintering 30 km ENE near the village of Baila, but unfortunately we have stopped receiving data from his transmitter due to a technical fault. There is more information here.

LS3 seen at the Sine-Saloum Delta

Last month we were thrilled that LS7, one of the eight juvenile ospreys that we translocated to Poole Harbour last summer, had been seen at Ile des Oiseaux in the Sine-Saloum Delta in Senegal. You can read more about the sighting here. The survival rate of juvenile ospreys in their first year is generally very low (only around 30% make it back to the UK as a two year-old) and so it was encouraging that LS7 had been seen at such a superb place for wintering ospreys.

Amazingly we now know that LS7 wasn’t the only Poole juvenile to be seen at the Sine-Saloum Delta in January. We have now been contacted by Jean-Louis Carlo to say that he photographed LS3 on New Year’s Day at Nema Bâ in the south of the delta. LS3 set-off from Poole Harbour two weeks after LS7, on 9th September but amazingly Jean-Louis’ sighting was just 21 km from the spot where LS7 was seen three weeks later! This really is fantastic news and proves that the two juveniles must have set-off from Poole in excellent condition; undoubtedly aided by the daily supply of fresh fish provided by the team at Poole before the juveniles departed. This is an essential requirement if a young osprey is to survive the perilous first migration to West Africa and then find somewhere safe to winter.  As we explained in the recent blog about LS7, LS3 may not have lingered at the Sine-Salum Delta, but Jean-Louis’ sighting is an extremely encouraging sign. This incredible place will now be on the young osprey’s radar, and may well become his future wintering site.

LS3 at the Sine-Salum Delta on 1st January 2018 – photo by Jean-Louis Carlo

LS3’s ring is clearly visible in the photo

Both LS3 and LS7 are likely to remain in West Africa for the whole of 2018, but the fact that they have both been seen alive means that there is every chance that we may see them back in Dorset in spring 2019. Here’s hoping!

Very many thanks to Jean-Louis for this fantastic news.

You can check out the location of the sightings of LS3, LS7 and other colour-ringed ospreys from the UK on our interactive map.

LS3 and LS7 were seen just 21 km apart in the space of three weeks