Comparative influence of anthropogenic landscape pressures on cause-specific mortality of mammals

The Human Influence Index (HII) quantifies anthropogenic landscape pressures by combining eight measures of human influence: human population density, built environments, crop lands, pasture lands, lights, roads, railways and navigable waterways. The comparative influence of the HII components on cause-specific mammal mortality remains unexplored. Using a database of North American mammal cause-specific mortality, we compared the influence of these components on proportion of mammal mortality resulting from harvest, vehicle collision, predation, and overall anthropogenic mortality. Our dataset consisted of 487 studies that monitored the fates of 48,551 individuals across 70 species with 17,837 mortalities of known cause. For both adults and juveniles, human population density best explained proportion of mortality from anthropogenic causes and showed a positive relationship. Human population density also provided best model fit for adult harvest mortality at low HII values. Lights, built environments, and human population density explained similar variation in adult vehicle mortality, whereas human population density provided best fit for vehicle mortality of juveniles. Predation was negatively associated with human population density and provided best model fit for both age classes. Our work indicates that the effectiveness of conservation programs for North American mammals could be enhanced by reducing the negative consequences of human population density. (c) 2021 Associaca tilde o Brasileira de Cie circumflex accent ncia Ecol ogica e Conservaca tilde o. Published by Elsevier B.V.

Automated summary

This study examined the influence of human influence factors on cause-specific mammal mortality using the Human Influence Index (HII) and a database of North American mammal mortality. The results showed that human population density was the most important factor, positively related to anthropogenic mortality but negatively related to vehicle collision and predation mortality. The findings suggest that reducing the negative impacts of human population density can enhance conservation efforts for North American mammals.