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Weaver Wednesday 3 [260] - Range changes [23]: Fan-tailed Widowbird

2017-06-07 (784)

gravit8 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
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).