https://www.selleckchem.com/products/dcemm1.html The extent to which migratory bats forage at stopover sites or while in migratory flight is poorly understood. Endogenous fat stores have lower δ13C values relative to the dietary substrates from which they were synthesized, and so, the fed versus fasted state of bats should be discernable by comparing their breath δ13C at capture to that after a known period of fasting. We captured silver-haired bats (Lasionycteris noctivagans) at a stopover site at Long Point, Ontario, Canada, during spring and fall migration. We collected breath samples at capture and after fasting in captivity for 12 h, providing a fasted-state δ13C value corresponding to metabolism of fat stores. We also collected and weighed fecal pellets produced while in captivity. Breath δ13C values at capture were positively correlated with mass of feces produced. During spring migration, δ13C values of breath CO2 at capture were low and similar to fasting values, but increased with date consistent with increased foraging at stopover and reliance on exogenous dietary nutrients as the season progressed. The opposite temporal pattern was found during fall migration. Our findings suggest that bats forage during migratory stopover when environmental conditions permit despite potential time trade-offs between feeding and travel, and the energy savings resulting from torpor during roosting. This study provides insight into the eco-physiology of bat migration and shows the importance of foraging habitat for migratory bats.Ecologists have long wondered how plants and algae persist under constant herbivory, and studies have shown that factors like chemical defense and morphology can protect these species from consumption. However, grazers are also highly diverse and exert varying top-down control over primary producers depending on traits such as body size. Moreover, susceptibility of plants and algae to herbivory may vary across life stages and size classes, with ju