This study will look at the behavioural thermoregulatory strategies that different species of larks and chats use under extreme temperatures. The study is divided into two parts: measuring the thermal landscape (i.e. range of temperatures available in the open, under bushes etc at any given air temperature) and understanding how the body mass of different species of larks affects their use of the thermal landscape at different air temperatures, and what the consequences are for foraging and activity patterns, and ultimately their vulnerability at extremely hot temperatures. To measure the available thermal landscape black-globe thermometers fitted with iButton temperature dataloggers will be deployed in representative microsites: under and on top of bushes of differences species and sizes, in the open. To investigate the impact of temperature on behaviour of the larks and chats, repeated focal observation and scan sample techniques will be used to collect behavioural data (time-activity budgets, microsite use and where possible foraging success) for four species of larks across different time-of-day and temperature periods.