Figure 2:

Differences in attribution of causal relationships between conservation (A and B) and conservation physiology studies (B and C). Physiological knowledge of a species (or other system of interest) can increase the precision with which mechanisms for responses are identified. Here, climate warming is causing a species of conservation concern to experience gradual decline, when taken as an average across all populations (A). However, an examination of distinct populations for this species (B) shows that population 3 is declining rapidly, while populations 1 and 2 are not. Knowledge of the thermal tolerance of this species can help to explain this pattern (C); individuals from population 1 are at the optimal temperature for the species and, therefore, the population has not experienced temperature-related declines. Individuals of population 2 are experiencing temperatures that are not optimal, and their function is not maximized; however, they are within the tolerable range of temperature for the species and, therefore, are not experiencing significant population decline. Population 2 is at risk of accelerating decline due to climate change in the near future. Individuals of population 3 are experiencing temperatures warmer than the optimal tolerable range for the species (shaded in beige), leading to deterioration of function at the individual level, which extrapolates to population-level decline. These individuals are experiencing sub-lethal effects and are approaching the critical temperature at which mortality occurs. Population 3 is at risk of local extinction, which could increase endangerment risk for the species. Active management of the population is warranted, and could involve translocation, removal of dispersal barriers, etc.