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Weaver Wednesday 3 [258] - Range changes [21]: Red-collared Widowbird

2017-05-24 (782)

gravit8 Weaver Wednesday 3: range changes in S Africa (species text)

Red-collared Widowbird Euplectes ardens

Red-collared 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).

Red-collared Widowbird
Red-collared Widowbird,
figure from Birdpix

Range changes in SA

Range change summary
More 4 lists 30 lists
increases n % n %
Decrease 234 38 115 32
Tiny change 152 24 104 29
Increase 230 37 140 39
Total 616 100 359 100
In South Africa the Red-collared Widowbird has slightly 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.

1. The core range of this widowbird in South Africa lies from eastern Mpumalanga to southern KwaZulu-Natal, excluding Zululand (this core has high reporting rates in SABAP2)
2. The Eastern Cape overall has slightly more decreases than increases between SABAP1 and SABAP2.

Overall the Red-collared Widowbird shows a fairly stable population between SABAP1 and SABAP2. There are many grids with large or small changes, but these are fairly patchy.

Range changes elsewhere

No major range changes known elsewhere, but it may wander in response to rainfall, eg. recorded 170km west of its known range at Selukwe, Zimbabwe, probably due to rainfall (Donnelly 1973a).