The project

Our knowledge of ecology of migrants in their wintering grounds is extremely poor and severely hampers our ability to explain these declines and conserve this group of species. We lack even basic information about when birds arrive, the habitats they use and how they move around Africa.

The aim is to understand how Palearctic-African migrants use and move around the different vegetation zones found in West Africa, ranging from the semi-desert Sahelian region in Burkina Faso to the lush tropical rainforest in southern Ghana, and whether habitat change may impact them on their wintering grounds.

During the temperate winter of 2009/2010, using point count methodology and mist-netting, we recorded migrants along a degradation gradient at five different stations on a north-south transect. In 2010/2011 we plan to re-visit these sites as well as roving further afield to get a broader picture of migrant habitat use.

14th November - 26th November

The evening of 14th November saw my (Chris Hewson, BTO team co-leader) arrival from the UK for a month’s fieldwork before Christmas. This coincided precisely with the remnants of the existing team (Chris O, Tina and driver Abraham with Mohamed having returned north to Burkina) arriving back in Accra to regroup and have the car repaired before returning to the field. Unfortunately the latter turned into something of a saga – when we took the car to the Toyota dealership on Monday morning we were told that fixing the source of the leaking oil was not a simple task and that although work would begin later that day, the following day was a public holiday so we shouldn’t expect it to be finished until the end of Wednesday. A Thursday morning start didn’t seem too bad a proposition but Wednesday afternoon became Thursday and Thursday became Friday morning before we were told the car was ready for collection. Our patience was tested to the limit upon arriving at Toyota on the morning of Friday 19th to be told that in fact the car wasn’t ready and not only that, its completion required a part that the dealership didn’t have! To cut a long story short, we were promised the car would be ready if we came back after the weekend and Monday afternoon was agreed.

Taking pity on our plight, GWS kindly loaned the team a car for the weekend so we could at last get some fieldwork done and we headed down to Brenu Beach, west of Cape Coast, where we had arranged to meet Justus Deikumah, a PhD candidate from University of Cape Coast, so that he could train us in blood sampling techniques as part of a project looking at chronic stress in birds in forest fragments. Upon arrival the whole area appeared much greener than at even a month earlier the previous year. Despite being rained off on two of the three mornings we tried to ring here, we did catch an array of Afrotropical species as well as two migrants – a Garden Warbler and a Nightingale. A quick look around the hill immediately behind our accommodation produced 3 Nightingales calling, 3 Spotted Flycatchers and about 8 Yellow Wagtails. Other birds in the area included Slender-billed and Orange Weavers (two species restricted to the coastal zone in West Africa - an active colony of the latter with nests hanging from mangroves over a nearby lagoon providing pleasant distraction), Brown-headed Tchagra and a Snowy-crowned Robin-chat seen repeatedly chasing a Spotted Flycatcher from one particular woodland edge – the territorial behaviour of the intra-African migrant has previously been well documented but we were surprised to witness a Spot Fly rather than the expected Nightingale being on the receiving end!

Above: Tina (GWS) juggling yams on our way to Bia NP.

The team returned to Accra and finally collected the car late on the afternoon of Monday 22nd. With tyre changing / balancing / wheel alignment still to come, as well as packing our equipment and doing our food shopping, it wasn’t until Tuesday late-morning that we left Accra behind and were off on the next phase of our field mission. We made good progress along the coast but wouldn’t make our destination that day. However, after refuelling and resting overnight in Takoradi, on Wednesday morning the team headed on to the Bia NP with only one thing on their minds: Phylloscopus sibilitrix.
Given that the Wood Warbler has declined by 61% on the last 13 years alone in Britain and by 26% in 17 years in Europe, it was with hope rather than expectation of finding this species that the team set up camp at New Debiso, at the northern end of Bia NP. The winter habits of this species are not well-known and although they had been reported as fairly common at this site 5-6 years ago, they had not been found by the same team last winter. Our first morning excursion in the forest on 25th reminded us why we knew we would do well to find any, even if they were around: birds of any species are not easy to spot, let alone identify, in the forest canopy. Armed with the knowledge that we were most likely to find Wood Warblers around flowering trees (where like other species they feed on insects attracted to the flowers) we set off looking for clearings from which we could view the canopy. We didn’t find any sign of Wood Warblers at all but did record a good selection of forest-zone birds including Usher’s Flycatcher, Blue Cuckoo-shrike, African Emerald Cuckoo and African Goshawk. Whether Wood Warblers were present and we failed to find them, whether we were too early in the winter or whether they don’t occur in Bia in significant any numbers any more we just didn’t know….

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