It’s been an exciting field season so far at Tswalu Kalahari Reserve for the Sparrow Weaver Project team, with a wave of new chicks arriving in our study population. Since the start of the field season in October, we have found around 82 clutches and broods, and the adults are still working hard to raise the new recruits.
Led by Dr Andy Young (University of Exeter, UK), the Sparrow Weaver Project has monitored a population of white-browed sparrow weavers in a 2km2 area of Tswalu every year since 2007. Sparrow weavers are social birds that live in groups of up to 14 individuals, which occupy distinct year-round territories. They are cooperative breeders, which means that breeding individuals within each group (the dominant male and female) are helped by other group members to raise offspring. We are currently monitoring around 40 sparrow weaver groups, with most of these now caring for eggs or chicks.
Sparrow weaver nests are highly conspicuous and are easy to locate in the Kalahari environment. Using a special nest camera, the Sparrow Weaver team regularly checks the inside of sparrow weaver nests for newly laid eggs. Once found, we monitor the eggs closely to determine their hatching date, and then monitor the progress of nestlings through to fledging. When nestlings have grown large enough, we fit a uniquely numbered metal ring to one of their legs. This allows us to easily identify and monitor individuals over the course of their lifetimes.
The long-term monitoring of this wild population of sparrow weavers provides us with a unique dataset, giving us an opportunity to ask fascinating evolutionary questions. For example, a current focus of our research is to understand how social behaviour impacts life histories and the causes and consequences of ageing in natural populations.
The Sparrow Weaver team are looking forward to the rest of the field season!
Images by Vanessa Schreiber and Mark Hase Click here for more information about the Sparrow Weaver Project