Thirst protects cottonmouths from infection

2022 has been an extraordinarily dry year for some regions of the planet. Rivers are running low, reservoirs shrinking and animals going thirsty. However, drought is a routine part life cottonmouth (Agkistrodon conanti) population Snake Key, off Florida coast, USA. ‘The islands Cedar Keys recently formed relic sand dunes recent patterns sea level rise in northern Gulf Mexico suggest have isolated from mainland 3500–4500 years’, says Mark Sandfoss University Florida, With access only to rainfall, snakes often go Harvey Lillywhite, also had hunch that may gain benefit their dehydrated lifestyle. ‘Recent studies found as reptiles become dehydrated, ability immune system protect them disease improves’, Sandfoss. Could same hold true castaway cottonmouths?Sandfoss headed over Key search marooned vipers. ‘They conceal themselves under vegetation but gave away by attempting quick strike at passing boot. This both helpful unsettling’, chuckles He picked up each animal with snake hook before securing it bucket collecting tiny blood sample, ‘which requires incredible trust person holding venomous while I draw tail’, admits. sample hand, he transported back lab where offered drink find out how they were, weighing monitor mass took on water quench thirst. In addition, François Brischoux (La Rochelle Université, France) checked animals’ corticosterone levels – hormone which usually rises when thirsty stressed were.Sure enough, cottonmouths were more (with plasma concentration 344.1 mosmol kg−1) keener than well-hydrated (309.1 kg−1 concentration) nearby marshy wildlife reserve Paynes Prairie, FL, Prairie snakes. Yet, team tested well primed snakes’ was fight infection, island no better prepared cousins. But would immunity alter thirst changed?This time, 17 (eight nine mainland) providing unlimited supply ensure hydrated testing attacked fake infection. Then, removed reptiles’ bowls until lost one-fifth body thirsty, not dangerously so rechecking strength system. Finally, returned allowed slake retesting 48 h later.Both produced powerful responses after losing 20% water. Dehydration made resistant although response rapidly normal long drink. Even though routinely experience thirst, infection deprived And becoming increasingly essential we understand react waterholes climate continue shifting face greater environmental uncertainty.