Climate change can alter the ecology of natural systems through various mechanisms, such as direct thermal effects on a consumer. However, consumers may employ behavioral mechanisms in response to warming. Among these may be spatial or temporal shifts in activity, making use of thermal heterogeneity on the landscape. Despite this, few studies consider the role of behavioral plasticity and spatial or temporal heterogeneity in the context of climate change. I conducted experiments to evaluate the importance of behavior in mediating the net effects of warming at the population and the individual level using captive white-tailed deer (Odocoileus virginianus). I created thermal heterogeneity over feeding stations using opaque and translucent roofing material. Feeding activity and consumption were monitored at these feeders. Activity patterns revealed deer disproportionally used the shaded feeder during the daytime and the unshaded feeder during crepuscular periods. I found that deer consumed less feed in group and individual experiments when feeders were unshaded. My results suggest that deer can use heterogeneity in the environment that may mediate the net effects of climate change. Furthermore, maintaining thermal heterogeneity may mitigate the direct effects of climate change on the consumer, but may lead to indirect effects at the community level.

As a unique habitat that encompasses steep environmental gradients, it is important to evaluate threats posed to the intertidal zone by rapid climate change. It is thought that intertidal ectotherms are living close to their physiological limit; therefore slight changes in temperature could result in high levels of mortality. Past studies on intertidal species measured thermal tolerance under constant temperatures, neglecting to consider the impacts of natural variation in field temperatures. I conducted a study on the barnacle, Balanus glandula, to assess if a variable thermal environment would alter thermal tolerance. Barnacles were acclimated in an intertidal mesocosm to either daily cold (maximum 20.4◦C), daily warm (maximum 26.5◦C), or variable (two days cold, two days warm) low-tide temperatures. I measured each barnacle’s critical thermal maximum (CTmax) by increasing air temperature 6◦C/hour and identifying the point at which the barnacle ceased to function. Barnacles exposed to any warm temperatures demonstrated an increased thermal tolerance, suggesting that this population of barnacles is capable of shifting their thermal maximum. Furthermore, acclimation to thermal heterogeneity raised thermal maximum, reinforcing the need for future thermal tolerance studies to incorporate biologically-relevant thermal regimes in laboratory experiments. These results demonstrate that B. glandula in the field are well-adapted for increasing air temperatures.