Interspecific interactions among two resident breeding Sylvia warblers, S. melanothorax and S. conspicillata, and a recent invader to Cyprus, S. melanocephala. (#870)
There has been much interest of late in how interspecific interactions shape species distributions. One aspect that has been difficult to account for is how long interactions between related species have been going to be able to estimate when species initially came into contact and how their ranges have been affected by the length of the interaction. Sardinian warbler S. melanocephala has only recently become a breeding bird on the island of Cyprus, allowing us to better understand the impact of its competition with the other breeding Sylvia warblers, spectacled warbler S. conspicillata and Cyprus warbler S. melanothorax, which breeds only in Cyprus. In 25 years Sardinian warbler has spread to breed on approximately half the island, displacing Cyprus warbler from some of its former breeding range. We use a combination of surveys, playback experiments, and habitat preference analyses to determine the effects the new arrival has on its congeners. Furthermore, a new melanistic morph of Sardinian warbler has evolved on the island, having appeared over the last few years. We explore the factors that could lead to the new morph expanding its population.