Weaver news

Weaver Wednesday 3 [244] - Range changes [7]: Lesser Masked Weaver

2017-02-15 (767)

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

Lesser Masked Weaver Ploceus intermedius

Lesser Masked 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).

Lesser Masked Weaver
Lesser Masked Weaver,
figure from Birdpix

Range changes in SA

Range change summary
More 4 lists 30 lists
increases n % n %
Decrease 90 28 54 29
Tiny change 56 17 37 20
Increase 183 55 96 51
Total 329 100 187 100
In South Africa the Lesser Masked Weaver 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. Greater Durban area, and inland, in KwaZulu-Natal.
2. Northwest of Gauteng.
3. Western edge of its range in Northwest Province; the souther grid is Barberspan where it has been regularly ringed over the last few years.

Large decreases appear to have occurred:
4. central Zululand, this decrease may be due to the drought in the region over the last few years.
5. Kruger National Park.

Range changes elsewhere

DR Congo: at Kinshasa, out of range (Punga 2015a).