Monitoring Results
Temperature
The effects of extremely high temperatures on monarch survival have also been studied. Zalucki (1982) and Malcolm et al. (1987) showed that temperatures greater than 29°C can be detrimental to larval development. Heather York, working in the U of MN Monarch Lab, did a detailed study of heat stress on monarchs and found that they could stand short periods of exposure to even 36°C, but that long periods of exposure resulted in high mortality (York and Oberhauser 2002).