Migratory birds are bringing more disease-carrying ticks to the northern hemisphere, a new study suggests.

Scientists fear this could lead to a rise in Lyme disease in Britain, which causes flu-like symptoms and can make people very ill if not treated quickly.

Climate change is blamed for expanding the range of migratory birds and allowing ticks previously unable to survive in colder conditions to breed and thrive in northern Europe.

Ticks from warmer countries may carry pathogens not seen in colder regions, meaning people could become infected with new tick-borne diseases.

These can be transmitted to humans and pets like cats and dogs by parasites from migratory birds, which can travel up to 3,000 miles.

Scientists say changes in global temperatures caused by climate change now make it easier for some ticks to establish themselves as invasive species.

This can happen quickly, as in the case of the Asian longhorned tick which was first detected in New Jersey in the United States in 2017 and has since been found in 14 other states.

Dr Lorenza Beati of Georgia Southern University, co-author of the study, said: “The geographic distribution changes very rapidly in many tick species.

“For some migratory exotic ticks, global warming may create conditions in their northern destination similar to their usual range.

“If warmer climatic conditions are combined with the presence of vertebrate hosts suitable for all life stages of ticks, the chances of establishing their presence will increase.”

In studying the dispersal of ticks by migratory birds, scientists installed nets at six locations where birds stop to rest along the northern Gulf of Mexico.

When ticks were found, they were removed and saved for later DNA analysis to confirm the species and identify the microorganisms they carried.

Nearly 15,000 birds were sampled and 421 ticks were collected from 164 birds, representing 18 different tick species.

Dr Shahid Karim, of the University of Southern Mississippi, lead author of the study, said: “If conditions become more favorable for tropical tick species to establish themselves in areas where they would otherwise have been unable to before, then there is a chance that they could bring new diseases with them.