A University of So Paulo study published in Science (Thraupis Sayaca) shows that birds and plants are linked in seed dispersal networks. Credit: Rodrigo GusmoBirds are essential for the dispersal of seeds from more than 70% of flowering plant species. Birds eat fruit from many different plants. Bird-plant interactions create a complex web of interconnected networks.The University of So Paulo's Institute of Biosciences in Brazil found that each bird species' evolutionary stability is dependent on its position in these networks. This increases with the number of interactions it has with potential partners and the number of connections it maintains.The study was supported by So Paulo Research FoundationFAPESP, and published in Science.Gustavo Burin, the first author of this article, stated that bird species that are located in more central positions within a network and have more connections tend to be more stable in macroevolutionary terms.Burin says that establishing a correlation between species interactions, and their evolutionary dynamics, was a difficult task because it required the analysis of two processes: seed dispersal and evolution. These processes occur at completely different times. While seed dispersal occurs every year, evolution takes place over many years.He said that he worked for four years to integrate data from 468 species of birds belonging to 29 seed dispersal network. "We proved that the more bird species establishes links with other species, the better its evolutionary chances.""It is clear that the more stable a bird species evolves, the better our chances of observing its relative importance within a seed dispersal network. This is measured by the pattern and number of interactions it has."Species in central positions within a network have two important characteristics: they either live longer than others or they belong in groups that accumulate many species over a short period of time so that if one species dies, many similar species are replaced."The Rufous-bellied thrush, (Turdus rufiventris), and the Sayaca tanager, (Thraupis sayaca) are two examples of longevous birds that are native to Brazil."We are emphasizing the importance interaction with plants for the evolutionary success and viability of bird species. However, the reverse could also be true. Plants that have more bird species that can disperse their seeds are more likely survive and reproduce. Burin stated that seeds can be transported dozens of kilometers away from plants if a dispersing vertebrate is present.This mechanism works better in warmer, wetter regions that are less susceptible to seasonal fluctuations. It's no surprise that the Amazon region of Colombia and Southeast Asia are home to some of the most important areas for biodiversity and animal species in the world.The study combined ecological data with mathematical and computational modeling and analytical tools derived through complex network analysis. Paulo Guimares Jr., Tiago Quental are the other co-authors.Continue reading Bird species that are central to seed-dispersal systems have stable evolutionary linesGustavo Burin and colleagues, Macroevolutionary instability predicts interaction patterns between species in seed dispersal network, Science (2021). Information from Science Gustavo Burin and colleagues, Macroevolutionary instability predicts interaction patterns for species in seed dispersal network, (2021). DOI: 10.1126/science.abf0556
