Updates from our Cuckoos

Thomas is on the southern edge of the Sahara but he didn't get there via a long flight out into the Atlantic, as his map suggests. The satellite passing over the Cuckoo tags will sometimes receive a series of poor locations, and the coding behind the automatic map updates is such that it usually ignores these, sometimes we do get one of these slip through and this is the case with Thomas in the Atlantic. His journey across the desert will have seen him moving along the western edge of the desert before heading southeast into Senegal.

Having spent the last three weeks in northern France Sherwood is finally on his way south. On 21 July we recieved a series of locations from his tag that showed he had crossed the Pyrenees and was in Spain. He is just to the west of Olmedillas and around 100km (60 miles) northeast of Madrid.

In 2017 Selborne moved east from his post-desert crossing stopover site on 23 July, this year he made the same move on 22 July. He is now 570km (354 miles) east of his last location and has crossed the border into Burkina Faso.

Selborne left Spain on 11 July this year, heading almost due south into Morocco before drifting east into Algeria and then heading  west and on to southeastern Mali. He his in the same location, north of the capital, Bamoko, that he used as his post-desert stopover site in 2016. He moved west from this location on 23 July in 2016 but had arrived there six days earlier than this year. It will be interesting to see how long he remains here this year.

Locations received from Cameron's tag during the early hours of 17 July showed that he was on the move, heading south and east into Nigeria. By breakfast he had reached the Sokoto River and was just south of the town of Kalgo. This will show on his map when it automatically updates.

During the last couple of days Bowie has moved south and east and is now in Chad and just to the northwest of Manda National Park. Since leaving the New Forest on 12 June he has flown 4,893km (3,040 miles). He has averaged 139km (86 miles) per day during his travels so far.

Sylvester has crossed the Pyrenees and is in central Spain. He is to the west of the medieval town of Avila. He has Selborne, a New Forest Cuckoo about 70km (45 miles) to his west and Raymond, a Knepp Estate Cuckoo 200km (128 miles) to his east. It will be interesting to see which of these is the first to head south from here.

Having spent the last 6 days on the southern edge of the Pyrenees, PJ has moved. He is now 195km (121 miles) southwest of his previous location, and is to the west of Zaragoza. Might this be the start of his big push south?

The winds do seem to have helped Cameron across the desert. During the afternoon of 12 July his tag showed that he was in the very southeast corner of Niger, close to the border with Burkina Faso. He is 19km (11 miles) north of the Niger River in an area of acacia forest and on the southern edge of the desert.

It seems Victor might have had an interesting flight over the desert. He started his crossing in a southeasterly direction but about a third of the way into the desert he began heading west and continued on this track all the way to Burkina Faso and the southern edge of the desert. Burkina Faso has been his staging area for the last two years, in 2017 he arrived here on 19 Jul and on 1 August in 2016.

It is interesting to look at the winds during his crossing. For the first part, when he was heading east, he was flying into a light headwind coming from the southeast, roughly at the point he started heading west he met a light headwind coming from the southwest. We know that birds prefer to fly into light headwinds, doing so gives them a greater degree of control over their flight than a tailwind would, but it is great to see this in action. Of course if the headwind is too strong birds will sit it out until conditions improve.