Assessing the thermoregulatory capacity of forest-dependent tropical birds living in forest fragments

Climate change is rapidly altering ecosystems, threatening biodiversity and ecosystem services. Forest fragmentation exacerbates these challenges by altering microclimatic conditions, such as through increased exposure to solar radiation, which contributes to harsher thermal environments, particularly in tropical regions. Diurnal active birds are particularly vulnerable to heat stress due to their high surface-to-volume ratio, which causes them to rapidly absorb heat, and their limited heat dissipation mechanisms. Examining thermal physiology is essential for understanding how species cope with the combined impacts of climate change and forest fragmentation, yet this perspective remains underexplored, especially for tropical forest species. This study aims to assess the thermoregulatory capacity of tropical forest birds in the fragmented forests of the Taita Hills, Kenya. We will assess their thermoneutral zone (TNZ), evaporative cooling capacity, and heat tolerance limits (HTL). We hypothesize that smaller species will be more susceptible to heat stress, with narrower thermoneutral zones and more restricted HTL than larger species. This research will fill critical gaps in understanding the thermal biology of tropical forest-dependent species and their vulnerability to climate change.