Weaver news

Weaver Wednesday 3 [248] - Range changes [11]: Eastern Golden Weaver

2017-03-15 (771)

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

Eastern Golden Weaver Ploceus subaureus

Eastern Golden Weaver, 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).

Eastern Golden Weaver
Eastern Golden Weaver,
figure from Birdpix

Range changes in SA

Range change summary
More 4 lists 30 lists
increases n % n %
Decrease 31 22 21 19
Tiny change 30 21 23 21
Increase 83 57 63 59
Total 144 100 107 100
In South Africa the Eastern Golden Weaver has many 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. The lowveld of Swaziland, with a recent range expansion north into Mpumalanga.
2. The KwaZulu-Natal midlands.

Areas with mixed changes:
3. KwaZulu-Natal coast - most grids show small changes (either increases or decreases), but some grids show large changes.

Areas with very large decreases:
4. Eastern Cape, on the interior edge of its range.

Range changes elsewhere

Tanzania: range extension to Tarangire NP (Demey 2007c).