A framework for understanding how and why animals die

Roxanne Beltran , Scott Yanco, Ruth Y. Oliver, Marm Kilpatrick

Mortality is a fundamental demographic process that shapes both populations and ecological communities. Yet, how and why animals die is just as important as the simple fact of whether or not they do. A richer understanding about drivers of death across taxa is needed to advance ecological theory and to improve conservation practice. Both require identifying the causal pathways that lead to death; misattributing mortality sources, such as emphasizing predator control when declines are actually driven by food limitation or habitat loss, can lead to ineffective interventions and incorrect inference. We argue that there is a need to conceptually distinguish and identify upstream drivers (whys) from downstream mortality events (hows) and to examine their interaction in causal pathways. We provide a conceptual framework for mapping these linkages across space and time. Together, the framework and associated approaches will clarify the mechanisms that shape mortality in wild animals and strengthen our ability to detect vulnerability early enough to intervene effectively. These gaps are especially important as climate change and human disturbance alter both vulnerability drivers and mortality outcomes.