Weaver Wednesday 3: range changes in S Africa
(species text)
Fan-tailed Widowbird Euplectes axillaris
Fan-tailed Widowbird, Range-change map between SABAP1 (1987-1991) and SABAP2 (2007-current).
Red, orange and yellow = cells with very large, large, and small relative decreases
Blue, dark green and light green = cells with very large, large and small relative increases.
Cells = quarter-degree grid cells; Only cells with at least 4 checklists in both SABAP1&2 shown. All cells had this species recorded in SABAP1 or in SABAP2 or in both (more about interpretation at Biodiversity Observations 7.62: 1-13).
Fan-tailed Widowbird, figure from Birdpix
Range changes in SA
Range change summary
More
4 lists
30 lists
increases
n
%
n
%
Decrease
109
25
34
13
Tiny change
117
27
73
29
Increase
213
48
144
58
Total
439
100
251
100
In South Africa the Fan-tailed Widowbird has more grid cells with increases in reporting rate than cells showing decreases, between SABAP1 (1987-1991) and SABAP2 (2007-).
The points below match the points on the map above.
Areas with very large increases include:
1. Gauteng, western Mpumalanga and eastern Free State - there has been a range expansion into these areas since SABAP1, probably due to higher rainfall.
Areas with very large decreases include:
2. Northern parts of the Eastern Cape, although the reporting rate here is low.
Areas with small changes include:
3. KwaZulu-Natal - this is the core of its range in South Africa, and its population appears to be fairly stable here.
Range changes elsewhere
Mozambique: increasing on Inhaca Island (de Boer 1999a).
