In what ways do European shags influence the vegetation and biodiversity on the rocky cliffs of Mallorca?

European shags, as resident seabirds of the rocky cliffs of Mallorca, play a significant ecological role in shaping the vegetation and biodiversity of these coastal areas. Their presence influences the environment primarily through nutrient enrichment. The birds deposit guano, which is rich in nitrogen and phosphorus, onto the cliffs and surrounding soil. This natural fertilizer promotes the growth of certain plant species, particularly those adapted to nutrient-poor conditions, leading to changes in the overall composition and density of the cliff vegetation.

This nutrient input can create microhabitats that support a diversity of plant life, which, in turn, provides shelter and resources for various invertebrates and smaller fauna. The interaction thus extends beyond plant communities, fostering a more complex and vibrant ecosystem. However, the concentration of guano can also inhibit the growth of some sensitive plant species due to its acidity and salinity, resulting in a distinctive pattern of vegetation around European shag colonies.

Moreover, the presence of shags influences the biodiversity not only through vegetation changes but also by attracting predator and scavenger species that rely on seabirds for food resources. This dynamic adds an additional layer of biodiversity to the cliffs, making them hotspots for ecological interactions. In essence, European shags contribute both directly and indirectly to the ecological character and biodiversity of Mallorca’s rocky cliffs, highlighting their role in the natural heritage of the island.