Weaver news

Weaver Wednesday 3 [250] - Range changes [13]: Southern Brown-throated Weaver

2017-03-29 (774)

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

Southern Brown-throated Weaver Ploceus xanthopterus

Southern Brown-throated 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).

Southern Brown-throated Weaver
Southern Brown-throated Weaver,
figure from Birdpix

Range changes in SA

Range change summary
More 4 lists 30 lists
decreases n % n %
Decrease 20 50 15 45
Tiny change 5 13 4 12
Increase 15 38 14 42
Total 40 100 33 100
In South Africa the Southern Brown-throated Weaver has many more grid cells with decreases in reporting rate than cells showing increases, between SABAP1 (1987-1991) and SABAP2 (2007-).

The points below match the points on the map above.

Areas with very large increases include:
1. SE Mpumalanga, especially around Komatipoort - this species was not recorded in Mpumalanga prior to 2002.

Areas with very large decreases:
2. Northern coastal Zululand in KwaZulu-Natal.
3. Coastal KwaZulu-Natal has many grids with decreases although a few have large increases.

4. Southernmost limit - the furthest south record for this species is from Illovo, south of Durban (Oatley 1973a), but has rarely been recorded south of Durban since.

Range changes elsewhere

Zimbabwe: range extension to Mashumbi Pools along Zambesi River (Masterson 1987a).