Previous reproductive success informs nest-building decisions

Behavioral outcomes, including foraging efficiency and reproductive success, often improve with age and with repeated breeding attempts. Here we examined the role of previous experience on the nest-building behavior of wild blue tits Cyanistes caeruleus. In particular, we focused on how previous success or failure in rearing nestlings shapes nest-building decisions in subsequent years. We found that previous breeding outcome is important for predicting nest building decisions in blue tits: birds that had previously raised fledglings added insulating material at a similar rate as they had when they built their first nest. Some birds that had been previously unsuccessful changed their rate of adding insulating material and then were more likely to produce fledglings. These responses indicate that at least some of the decisions made by wild nest-building birds are based on their own experience of past breeding seasons. We investigated how past reproductive experience influenced the nest-building behavior of wild blue tits. Previously successful birds built their next nest the same way as they had their first, whereas previously unsuccessful birds did not. Some previously unsuccessful birds changed their nest-building strategy and were more likely to produce live young from their next nest. These observations support previous experiments that showed birds use their experience of past success when they build their subsequent nest.