Updates from our Cuckoos

New signals on the afternoon of 22 January show that PJ was continuing northwards and had made it 800km (just under 500 miles) north from Gabon to reach Cameroon. He is just north of the Mbam et Djerem National Park. 

Selborne has made a small movement north within Gabon of about 95km (60 miles) to an area he visited last year, just south of Waka National Park. Last year he moved north again towards the end of January and was in Ghana by January 31 so it might not be too long before we see some big northward movements from him and our other Cuckoos, into west Africa. 

PJ is already on the move northwards. From Angola on the 22 January, he travelled 755km (470 miles) in a north-easterly direction to get back to Gabon by the evening of 26 December. In 2016/17 his behaviour was similar, heading north from Angola to the centre of the Republic of Congo in the second week of January and moving on again north by the end of January. It's the beginning of his long journey home.

By the early morning of January 1, Peckham had arrived in Gabon, 570km (355 miles) south-west from his last location in the Central African Republic. His new location in the Haut-Ogooue region is just 55km (35 miles) away from PJ who has moved north from Angola, where he has spent some of this winter. Peckham has spent the last two winters in and and around this area in Gabon so we don't expect much further movement from him, now that he is in his wintering grounds.

Peckham has moved on from southern Chad where he has spent the last seven or so weeks and has journeyed 460km (295 miles). He is in the Mambere-Kadei region. In previous years he has continued on during December to the Congo Basin area and into Gabon. We are very pleased that despite his very late migration this year he is now close to the heart of the rainforest. Well done Peckham! 

Since 27 November Victor has journeyed 265km (170 miles) south within Gabon by the early hours of the 29 November.  He is now just south-east of Bongoville. 

As expected PJ has continued southwards. By 12 November he was just east of the Crystal Mountains in southern Congo and by 16 Nov he was in the Zaire region in northern Angola. Signals on 19 Nov revealed a further southerly movement of 160km (almost 100 miles) to the Coutada do Ambriz reserve. In total he has moved over 890km (590 miles) from his location on 14 November. He may still go a little further within Angola, as last year saw him venture to the Parc Nacional da Quicama, 170km (110 miles) further south. 

In 2017, we have been trialling the very latest satellite tracking technology - this year’s cohort were tagged with 2g tags from Microwave Telemetry.

We have, unfortunately, ‘lost’ contact with most of them already. It would seem that the smaller size of the new tag allows the solar panel, used to recharge the tiny battery, to become shaded by feathers, resulting in much less efficient charging of the battery, and consequently lower contact with the tag. Although some may have died, the lack of transmissions from the tags makes it impossible to assess this and in all cases, there were no indications that the birds were in trouble when we last heard from their tags.

This is exacerbated during the winter months by the birds spending more time under the canopy in the Congo rainforest. We don’t know how the batteries will fare when the birds begin their northward migration back to the UK. On leaving the rainforest the tags should receive more sunlight which might be enough to overcome feather shading, and if this happens some of the ‘lost birds’ could pop-up again in February or March, but it is possible that the prolonged shading will have caused irreversible damage to the much smaller batteries in the 2g model. We all have our fingers crossed.

As we move forward we are continuously looking for effective ways to continue gathering this important data for Cuckoos, and other species, to benefit our knowledge and ultimately wildlife conservation. We hope that next year we will be able to track a cohort of cuckoos without these issues arising. 

PJ has moved 290km (180 miles) south within Congo in the last week and is now in the Lekoumou region, 40 miles south of Bateke Plateau National Park. Last year he was in Angola by the 25 October and remained there until January so we expect him to continue moving south to reach the same area. 

Larry has continued south from Chad, where he's been since the beginning of September. By the 9 November he had covered 1175km (730 miles) to reach the Cuvette-Ouest region of Congo, not too far south-east from Victor in Gabon. He didn't stop here for long though and by the early afternoon of 11 November he was 760km (470 miles) further south in northern Angola.

Larry’s southward migration from the UK to Angola has been remarkable. Weather conditions during the stopover period in Italy were harsh, incredibly hot and dry conditions were experienced across the whole of the northern Mediterranean area with wildfires being a feature from Spain to Croatia. Presumably in response to these conditions, and the probable lack of invertebrate food, Larry moved north to Poland, undertaking a journey of around 1300km (800 miles), at a time when we would have expected him to head south across the Sahara. Larry spent several weeks in Poland, and it would seem a wise move, from here he was able to undertake his migration to sub-Saharan Africa via the Balkans, a part of the world we hadn’t seen him move through before. Even though his migration this autumn was unusual, he is right back at his wintering location in Angola.

In the previous two years we've been following him he has also ventured to Angola, but normally to a location in the north-east, where he has remained for a while before then heading west towards the coast. He appears to have gone directly to this area now and is north of Tomboco. It's likely that, as in previous years, he will remain here until at least mid-December or possibly even mid-January, depending on conditions.