Weaver Wednesday 3: range changes in S Africa
Sociable Weaver Philetairus socius
Range changes in SA
Range change summary
In South Africa the Sociable Weaver has more grid cells with decreases in reporting rate than cells showing increases, between SABAP1 (1987-1991) and SABAP2 (2007-). The points below match the points on the map above.
Areas with very large increases include:
1. the Springbok area,
2. the area north of the Carnarvon to Britstown road,
3. near Barkley West (this is on the southern edge of the Ghaap plateau),
4. and the northernmost part of the Kgalagadi Transfrontier Park.
Large decreases appear to have occurred:
5. along the lower Orange River,
6. in the area from Augrabies Falls National Park to Kakamas,
7. and the area south of Christiana.
8. Absent on the Ghaap plateau:
There is a large gap in range of the Sociable Weaver around the Ghaap plateau, between Danielskuil and Vryburg. The weaver appears to have been absent from here for at least 100 years. There are new records (SABAP2) in the southern part of this gap (point 3), indicating that the Sociable Weaver may be colonising this area northwards.
Range changes elsewhere
Botswana: range extension near Konkwe Pan (Tyler 2008c).