The evergreen forests in the highest reaches of Western Ghats, known as shola sky islands, hold clues on how infectious diseases spread in wild birds.Latest research on the wild birds in the shola sky islands shows that some malarial parasites are more likely to invade avifauna communities than others.Climate change is likely to hasten the spread of infectious diseases among wild bird in the tropics, and better knowledge of disease dynamics will help us prepare for the future. The shola sky islands are a biologist’s delight. Surrounded by lowlands, these highest reaches of Western Ghats in peninsular India host radically different habitats and species. Covered in montane evergreen forests, the shola mountains rise from a ‘sea’ of low-elevation habitats, much like oceanic islands such as New Zealand that are surrounded by a sea of water. In both cases, the isolation limits the dispersal of species, making them ideal for studying the flora, fauna and avifauna. The latest in such research, conducted by scientists from India and the United States in the shola sky islands, may hold clues on how malaria-causing parasites in birds co-evolved with their hosts. This, in turn, might help understand how patterns of the disease emerge in natural wildlife or human communities. The new research, published in the Proceedings of the Royal Society journal, provides insights into why some parasites can rapidly establish themselves in novel places and impact native wildlife health, while others are less capable. It might help in checking the spread of infectious diseases that kill wild birds in large numbers. Some malarial parasites in birds, such as the unicellular Plasmodium species, are what scientists call generalists, which can rapidly invade a wide range of birds and cause large-scale infections and deaths. Whereas there are some so-called specialists parasites such as Haemoproteus species that can infect only a few bird hosts. Scientists from the Indian Institute of Science Education and Research (IISER) at Tirupati, the National Centre for Biological Sciences at Bangalore and the University of Georgia in the U.S. studied avian malaria (malaria in birds) caused by Plasmodium and Haemoproteus in the shola sky islands. “We demonstrate that some parasites are generalists and some are specialists, and that the generalist parasites like Plasmodium can rapidly invade novel communities, while specialists like Haemoproteus are less capable of doing so,” said Guha Dharmarajan, associate research scientist at the Savannah River Ecology Laboratory at the University of Georgia, and one of the authors of the paper. Thus, generalist parasites are more likely to be associated with disease emergence in natural communities, Dharmarajan’s team reported.