Salewski V., Falk K.H., Bairlein F. & Leisler B. (2002) Numbers, body mass and fat scores of three Palearctic migrants at a constant effort mist netting site in Ivory Coast, West Africa. ARDEA 90 (3): 479-487

Constant effort mist netting sites are widely used along the Palearetic-African migration system in areas north of the Sahara to collect standardised migration data. However, in sub-Saharan Africa such sites are scarce. We present data collected at a constant effort site which we ran once about every ten days in the northern Guinea savannah zone in north-east Ivory Coast from 1994 to 1998 in four successive European winters. The species most frequently caught were Willow Warbler Phylloscopus trochilus, Melodious Warbler Hippolais polyglotta and Pied Flycatcher Ficedula hypoleuca. Phenology data showed that the three species were more frequently mist netted early and late in the winter which was presumed to coincide with times of migration through the area. However, care must be taken when interpreting the data because Pied Flycatchers were abundant in other habitats in times when none was mist netted and therefore the data do not reflect relative abundance in the area. In Willow Warbler and Melodious Warbler, the data indicate possible itinerant behaviour. All three species show highest median body mass and scores toward the end of the winter but this is not significant in Pied Flycatcher, possibly due to the low capture rate. Although there are individual birds with high mass and fat scores, there is no indication that the area serves as an important stopover area for premigratory fattening as some sites in the Sahel region