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Weaver Wednesday 3 [259] - Range changes [22]: White-winged Widowbird

2017-05-31 (783)

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

White-winged Widowbird Euplectes albonotatus

White-winged 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).

White-winged Widowbird
White-winged Widowbird,
figure from Birdpix

Range changes in SA

Range change summary
More 4 lists 30 lists
increases n % n %
Decrease 228 36 99 30
Tiny change 129 21 86 26
Increase 273 43 147 45
Total 630 100 332 100
In South Africa the White-winged 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.

Areas with very large increases include:
1. SW Mpumalanga and much of Free State - there has been a range expansion into these areas since SABAP1 due to higher rainfall.
2. Eastern Cape - scattered records of small wandering flocks.

Areas with very large decreases include:
3. Along the Limpopo River/Botswana border.
4. Most of KwaZulu-Natal.

Range changes elsewhere

Zimbabwe: increase due to increase in rank grass around Harare (Brooke 1963a).

Exotic populations established in Australia: Appendix of Dyer EE, Redding DW, Blackburn TM. 2017. The global avian invasions atlas, a database of alien bird distributions worldwide. Nature Scientific Data 4 no: 170041.