Persistence explains differences in innovation in Darwin’s finches with a different foraging ecology

The capacity to create new behaviors is influenced by environmental
factors such as foraging ecology, which can lead to phylogenetic variation
in innovativeness. Alternatively, these differences may arise due to the
selection of the underlying mechanisms, collaterally affecting
innovativeness. To understand the evolutionary pathways that might enhance
innovativeness, we examined the role of diet breadth and degree of
extractive foraging, as well as a range of intervening cognitive and
behavioral mechanisms (neophilia, neophobia, flexibility, motivation and
persistence). Darwin’s finches are very suitable for this purpose: the
clade is composed of closely related species that vary in their feeding
habits and capacity to develop food innovations. Using a multi-access box,
we conducted an interspecies comparison on innovative problem-solving
between two diet specialists, extractive foragers (woodpecker and cactus
finch), and two diet generalist, non-extractive foragers (small and medium
ground finch). We predicted that, if extractive foraging was
associated with high innovativeness, variation would be best explained by
species differences in persistence and motivation, whereas if diet
generalism was the main driver then variation would be due to differences
in flexibility and responses to novelty. We found a faster capacity to
innovate and a higher persistence for extractive foragers, suggesting that
persistence might be adaptive to extractive foraging and only secondarily
to innovation. Our findings also show that diet generalism and some
variables linking it to innovation were unrelated to innovativeness, and
call for the development of joint experimental approaches that capture the
diversity of factors giving rise to novel behaviors.