Toutouwai can take down some of the world’s largest invertebrates, but if you’ve caught a 50 cm long earthworm, what do you do with it all? One answer is to shake it to pieces and hide it around your territory to snack on over the next day or so. This ‘caching’ strategy lets toutouwai make the most of temporarily abundant food by saving some for later.
Caching is widespread in the animal kingdom, yet there have been very few studies looking at how individuals develop caching behaviour. For her MSc thesis, Latu Clark investigated how juvenile toutouwai learn to make their caches. The results of her work have just been published in Behavioural Processes.
After young birds left the nest, Latu visited them a couple of times a week for up to 12 weeks. Each visit, she fed the birds several mealworms and documented their behaviour. If a bird cached, Latu monitored what happened to their cache (check out the image below of one of her juveniles inspecting the camera – if you look closely you might spot a cached mealworm in the log in the background). Her work demonstrated that it takes several weeks for juveniles to develop some aspects of adult-like caching behaviour, but that other components of caching appear spontaneously and do not change during development.
These results suggest that learning how to handle prey and hide it for later comes naturally to young toutouwai, but that they also require extensive experience to do it well. Interestingly, it also seems that toutouwai caching behaviour follows similar developmental trajectories to other, distantly related Northern hemisphere bird species.