USF: Stressed-out birds attractive to mosquitoes, increasing spread of diseases

Humans have the same "stress hormone" as birds
Posted at 5:30 PM, Aug 10, 2016
and last updated 2016-08-10 18:02:53-04
Researchers at the University of South Florida have made a discovery that could reveal a big problem in our fight to stop the spread of mosquito-borne diseases.
A new study from USF shows that "stressed" birds are twice as likely to be bitten by mosquitos.
When stressed, some birds release a hormone that makes them attractive to the mosquitos, say USF scientists.
Birds can be stressed by road noise, pesticides, and light pollution and that could be indirectly increasing the spread of mosquito-borne diseases.
Researchers also say people release that same "stress hormone" and might also be attractive to mosquitoes for the same reasons. USF's lead researcher tells ABC Action News they have not yet studied this possibility.
"The hormone causes changes in birds such as more activity, higher metabolic rate, and alterations in body temperature, all of which are probably perceived by the mosquitoes," explains Dr. Lynn Martin to ABC Action News. 
"It would be premature to claim that our results definitely transfer to people," says Dr. Martin, adding, "given the similar effects of the hormone birds and people, there are great reasons to do the research."
A paper describing Dr. Martin's research was published Wednesday in the Proceedings of the Royal Society B.
"Few studies have considered how stress hormone effects on individuals might influence population dynamics," said study lead author Dr. Stephanie Gervasi, who conducted the studies while carrying out her postdoctoral work at USF and is now at the Monell Chemical Senses Center in Philadelphia.  "For vector-borne diseases such as West Nile virus, the presence of [the hormone] corticosterone could influence pathogen spread through effects on contact rates with the mosquitoes that transmit it. In addition, stress hormones have negative effects on animals including immunosuppression and increased susceptibility to infections, which is why we are now also studying how corticosterone affects the birds' immune response to the virus."