This blog post is provided by Davide Baldan and tells the #StoryBehindThePaper for the paper “Songbird parents coordinate offspring provisioning at fine spatio-temporal scales“, which was recently published in the Journal of Animal Ecology.

Being a parent is certainly not an easy job. It takes a considerable amount of time and energy to successfully raise offspring. That is why each parent would like, if possible, to slack off and make its partner work harder. This desire generates a conflict of interest between the parents, commonly known as sexual conflict. Decades of research have suggested that parents do not work at their maximum capacity, and because of that, offspring and parents could suffer reduced fitness. To reduce the cost of parental conflict, researchers also point out that parents should constantly monitor each other and coordinate their activity, but we lack a clear understanding of the mechanisms by which parental coordination can occur.

In a recent paper in the Journal of Animal Ecology, we explored offspring provisioning behaviour of great tit (Parus major) pairs and investigated how parents coordinate their foraging movements. The great tit is a small passerine bird commonly breeding in European forests. Its breeding ecology has been studied for more than 50 years and it has become a model species to study parental care in the wild. Passerine birds, such as great tits, are hard working parents. Once chicks hatch, parents feed them with caterpillars and insects found in the territory near the nest. Great tit parents can visit the nest to feed the chicks once every 2 minutes and keep up with this rhythm for about 15-20 days until chicks fledge.

In this study, we monitored great tit reproduction in a woodland forest in the Netherlands during their breeding season. When chicks have hatched and are being fed, we captured parents at the nest and tagged them with a small-radio receiver. These tags are worn like a small backpack and transmit a radio pulse every 5 seconds, which is logged by small portable receivers. We placed receivers in a grid in the territory around the nest to triangulate the location of both parents during their provisioning activity. This allowed us to remotely monitor and collect undisturbed data of great tit foraging movements in their natural settings. We found that the foraging behaviour of great tit parents is highly coordinated in space and time, with parents changing their foraging locations in conjunction with their partners’ movements. This study represents the first detailed spatial and temporal description of foraging coordination in songbird parents in a natural context and opens a new avenue of research on breeding ecology of small birds.

These findings are also important for our understanding of how potential conflict between parents may be resolved. New evidence indicates that parental cooperation is more prevalent than we previously thought in animal families, and the more we investigate, the more we learn about the mechanisms that parents use to work together.

Read the paper

Read the full paper here: Baldan, D. & van Loon, E. E. (Early view). Songbird parents coordinate offspring provisioning at fine spatio-temporal scales. Journal of Animal Ecology. https://doi.org/10.1111/1365-2656.13702