Sylvia borin
Records: 42
Drafted by: Faansie Peacock
Draft Text Last Updated:
Distribution: There were widely scattered records (a typical dispersion pattern of migrants) throughout the region, including suburban areas. Virtually all records were from the moister east and south, but this is also an effect of more birding activity in those areas.
Gaps in Knowledge: Very few records exist for the W and SW. Occasionally newly arrived Garden Warblers will give the loud, striking and excited song that is uttered on the breeding grounds (pers. obs), but for the most part song in the non-breeding grounds is very subdued and soft – coupled with its cryptic plumage and unobtrusive nature, this results in Garden Warblers being widely under-recorded.
Habitat: Prefers moist, lush vegetation, where it keeps to the mid-stratum and canopy. Suburban gardens provide excellent habitat, as do riverine woodlands, moist, broadleaved woodlands, thickets on termitaria, wooded kloofs & dense vegetation on S facing slopes of koppies. Generally rare or absent in Acacia. Mostly insectivorous, but also fond of small, soft fruits, including those of the alien Lantana camara (SABAP 2:225), and often found foraging in fruiting shrubs and trees.
Status and movements: Non-breeding, Palearctic migrant. Recorded from 4 October (R. Geyser) to 30 March (L. Botha), although the first birds generally arrive around mid September (pers. obs) and depart for the boreal breeding grounds in April. Maximum numbers were recorded in February (16 records = 38%). A single record for 30 June is almost certainly erroneous, as this species is not known to overwinter in the region.
Population: Although widely under-recorded, this species does not reach the high densities of some other Palearctic migrant Sylviidae (e.g. Willow Warbler, Marsh Warbler), and records were mostly of single, well separated birds. The total population in the PCC/BiG region probably exceeds 1000 birds in some years, but due to the Garden Warbler’s unobtrusive nature and soft, indistinct song, exact estimates are difficult to make. One permanent territory in which Garden Warblers were recorded for at least 7 successive years in Elardus Park, Pretoria was 1.2 ha in extent (pers. obs), but densities are probably considerably higher in well-watered, lush suburban gardens than in natural vegetation.
Conservation: Not threatened. It has the ability to thrive in artificially created habitats, given that insecticides are used wisely.