A new Swedish study has found that birds’ immune systems are linked to the climate in which they live. As climate change accelerates, some birds may struggle to cope with emerging diseases because their immune systems “can’t keep up” with them, and the problem may appear in other animals.
Researchers at Lund University in Sweden recently published a paper in the Proceedings of the Royal Society’s Division of Biology, where they studied 37 species of birds living in different climates, analyzing the genetic diversity of each bird’s immune system and the temperature and precipitation in the areas in which they lived between 1901 and 2017.
The study found that the diversity of genes associated with a species’ immune system is associated with the climate in which it is located. Over the long term, many birds’ immune systems have been precisely “tuned” to enable them to cope “with ease” against diseases in specific environments and climates. Species that live in tropical rain-fed areas and do not migrate have the highest degree of genetic diversity associated with their immune systems and are capable of coping with more pathogens.
The study also found that rapid climate change poses a challenge to these “tailored” immune systems, which may not evolve at a pace that can keep pace with climate change, leaving many animals unable to cope with changes in the number and type of pathogens they will be exposed to. Northern Europe, for example, is becoming warmer and wetter, with the possibility of pre-existing diseases that pose a threat to some animals.
Researcher Emily O’Connor said the impact was not necessarily limited to birds, and the findings could also be applied to other animals because the immune system-related genes they studied were common in vertebrates.