The stopover behaviour of the Garden Warbler Sylvia borin in Obudu, southeast Nigeria

Abstract

The Garden Warbler breeds in the Palaearctic and migrates to sub-Saharan Africa for the non-breeding season. We studied its passage, body mass and moult at the Obudu Plateau in southeast Nigeria in October–December 2005 and December 2007–January 2008. In Nigeria, Garden Warblers in the Guinea savanna have been shown to increase body mass in October–November, preparing for migration to wintering sites further south. They begin to arrive at Obudu from mid-October and the numbers gradually increase with time; median date of passage was 3 December. This influx is clearly different from that which has been recorded for other sites in West Africa. The patterns in wing length and size-corrected body mass of individuals suggest a difference in the migration time of individuals of different sizes in the two years. Average fuel loads were lower at Obudu than has been reported in Central Nigeria. This, and the capture of moulting individuals, suggests that Garden Warblers may not embark on a longer journey southwards in mid winter, and possibly may even winter at Obudu.

Autumn phenology and morphometrics in the Garden Warbler Sylvia borin at the Ottenby Bird Observatory, Sweden

“…The Garden Warbler Sylvia borin is a long-distance, trans-Saharan migrant that breeds in the Western Palaearctic region and winters over a wide range of areas in eastern, western and southern Africa (Cramp 1992). The migration of this species has been well documented in Europe (e.g., Fransson 1995, Totzke 1998, Grattarola 1999) and in sub-Saharan Africa (e.g., Ottosson et al 2005, Smith 2007, Bayly & Rumsey 2010, Iwajomo et al 2011. In Europe, ringing-recovery data indicate that the direction of migration is south to south-west in autumn, i.e., towards the Iberian Ornis Fennica 89:233-240.…”