What is animal mortality during fires?



by LORENZO CIOTTI

What is animal mortality during fires?

Wildfires represent and have always represented the greatest risk factor for human activities and therefore, over time, methodologies have been created to prevent them and tools to fight them. In particular, with the increase in concentrations of people in closed or otherwise limited spaces, typical of urban agglomerations and with the increase in potentially dangerous activities, the risk of fires has increased over time.

For what has been said, fire detection has become a primary necessity to avoid damage to people and infrastructures. But fires are also the cause of death among animals. The study, Animal mortality during fire, published on the Global change biology, try to give an answer: "Earth's rapidly warming climate is propelling us towards an increasingly fire-prone future.

Currently, knowledge of the extent and characteristics of animal mortality rates during fire remains rudimentary, hindering our ability to predict how animal populations may be impacted in the future. To address this knowledge gap, we conducted a global systematic review of the direct effects of fire on animal mortality rates, based on studies that unequivocally determined the fate of animals during fire.

From 31 studies spanning 1984-2020, we extracted data on the direct impacts of fire on the mortality of 31 species from 23 families. From these studies, there were 43 instances where direct effects were measured by reporting animal survival from pre- to post-fire.

Most studies were conducted in North America (52%) and Oceania (42%), focused largely on mammals (53%) and reptiles (30%), and reported mostly on animal survival in planned (82%) and/or low severity (70%) fires. We found no studies from Asia, Europe or South America.

Although there were insufficient data to conduct a formal meta-analysis, we tested the effect of fire type, fire severity, fire regime, animal body mass, ecological attributes and class on survival. Only fire severity affected animal mortality, with a higher proportion of animals being killed by high than low severity fires.

Recent catastrophic fires across the globe have drawn attention to the plight of animals exposed to wildfire. Yet, our systematic review suggests that a relatively low proportion of animals (mean predicted mortality [95% CI] = 3% [1%-9%]) are killed during fire.

However, our review also underscores how little we currently know about the direct effects of fire on animal mortality, and highlights the critical need to understand the effects of high severity fire on animal populations."