If it ain't broke don't fix it: Breeding success affects nest-building decisions

Observational studies in the wild suggest that birds select material to build their nests based on functional aspects of material that promote reproductive success. How birds select material for nest building from the variety of materials available in their environment is unclear. In the current laboratory experiment we manipulated breeding success (i.e. raising fledglings) of zebra finch (Taeniopygia guttata) pairs to test if this affects the subsequent selection of nest material between a familiar versus a novel material, that differ in structural properties. All birds experienced one breeding attempt using coconut fiber as nest material during which their breeding success was manipulated: half of the breeding pairs fledged their nestlings while the remaining pairs had their eggs removed to simulate nest failure. In a second nest-building attempt, all pairs were given access to both familiar nesting material (coconut fiber) and a novel nesting material (white cotton string). Pairs that were successful in their first breeding attempt built their second nest with significantly more familiar material compared to novel material. Pairs that were unsuccessful, however, incorporated similar amounts of familiar and novel material in their second attempt. Our results show that experiencing either a successful or an unsuccessful breeding attempt influences how birds select between familiar and novel material with different structural properties (e.g. flexibility, thickness) to build a second nest. Moreover, our experiment shows that learning from experience plays an important role for decision making in future structure-building endeavors.