Weaver news

SESAW update

2011-12-05 (168)

SESAW (Survival Estimates in Southern African Weavers) is a project to study survival rates in weavers as these are often the most caught birds during general ringing. The project started in August 2009 and will run for at least three years before starting to analyse the data. A critical aspect of the project is recording if females have brrod patches or not, and recording males in full or partial breeding plumage - this will allow the analysis of definite adult males and females in addition to a general analysis.

After the first 10 months over 3500 weavers had been ringed and 9.4% of these had been retrapped (see news item here). Currently over 8000 weavers have been ringed with a retrap rate of 11.6% - the slight increase in retrap rate is encouraging, since survival analyses need retraps! Not included in the summaries are several thousand Cape Peninsula weaver records, which will be included in the final analyses.

The most ringed species is Southern Masked Weaver (4069 birds, 8.7% retraps), followed by Southern Red Bishop (2517, with a high 17% retrap rate). See summaries for each weaver species here.

Thanks to the ringers who have been ringing (mostly) every month at the same sites, to obtain data for this project!

Photo: male Spectacled Weaver, one of the SESAW species.