Weaver news

Weaver Wednesday 3 [263] - Range changes [26]: Overview

2017-06-28 (787)

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

Overview of range changes in SA

Weaver Wednesday 3 showed the changes in distribution for the 25 South African weaver species, based on the changes between SABAP1 (1987-1991) and SABAP2 (2007-current).

All species show increases and decreases of varying magnitude in different grid cells, but most weavers showed more increases than decreases. A new species was added to the South African list, the Chestnut Weaver! As a result this species shows the highest percentage increase, although only in a few grid cells. Six species had slightly more cells with decreases than increases: two savanna species (Red-billed Buffalo-Weaver, Scaly-feathered Finch), a wetland species (Southern Brown-throated Weaver), and 3 Euplectes species (Yellow Bishop, Yellow-crowned Bishop, Long-tailed Widowbird).

The species with the largest area of large increases is the Red-billed Quelea. Range expansions and large increases (in parts of their range) are also shown by White-browed Sparrow-Weaver, Thick-billed Weaver, Red-headed Quelea, Fan-tailed Widowbird, and White-winged Widowbird.

Major changes in the Kruger National Park are decreases by Lesser Masked Weaver, Village Weaver (large decreases throughout), Thick-billed Weaver, and Southern Red Bishop. White-browed Sparrow-Weaver and Scaly-feathered Finch are gradually expanding into the Kruger National Park.

Species list of weavers, showing overall changes in South Africa, with links to the Weaver Wednesday story.

Species Very big incr Large incr Small incr Small decr
[1]: Red-billed Buffalo-Weaver      
[2]: White-browed Sparrow-Weaver      
[3]: Sociable Weaver      
[4]: Scaly-feathered Finch      
[5]: Dark-backed Weaver      
[6]: Spectacled Weaver      
[7]: Lesser Masked Weaver      
[8]: Red-headed Weaver      
[25]: Chestnut Weaver      
[9]: Village Weaver      
[10]: Cape Weaver      
[11]: Eastern Golden Weaver      
[12]: Holub's Golden Weaver      
[13]: Southern Brown-throated Weaver      
[14]: Southern Masked Weaver      
[15]: Thick-billed Weaver      
[16]: Red-billed Quelea      
[17]: Red-headed Quelea      
[18]: Southern Red Bishop      
[19]: Yellow Bishop      
[20]: Yellow-crowned Bishop      
[21]: Red-collared Widowbird      
[22]: White-winged Widowbird      
[23]: Fan-tailed Widowbird      
[24]: Long-tailed Widowbird      
Totals 1 9 9 6
Weaver range change maps (excluding Chestnut Weaver)