Land use change and habitat fragmentation are widespread and ongoing processes worldwide and are key threats to large carnivore populations. Living in a human-dominated landscape often comes with increased risk of anthropogenic mortality as well as indirect behavioral and energetic costs, which may impact individual survival and population dynamics. The puma (Puma concolor) population in the Santa Cruz Mountains presents an ideal study system to investigate how habitat fragmentation impacts large carnivore survival, as animals occupy a range of different levels of human use or development in this variegated landscape. In this poster, I will present preliminary results from a survival analysis aiming to characterize the impacts of habitat fragmentation on adult puma survival. I have integrated spatial data from collared pumas into a Cox proportional hazards model to investigate whether housing density within an animal’s home range impacts both overall and cause-specific survival probabilities after controlling for demographic factors, and how temporal scale in home range calculation influences that relationship. I will also consider how individual variation in behavioral avoidance to housing density impacts mortality risk.
Results/Conclusions
Surprisingly, housing density within an animal’s home range alone is not a significant predictor of mortality risk. However, the change in housing density that an animal has experienced over the past month, together with housing density in their home range over the previous three months, are strongly predictive of mortality risk. In other words, animals who have experienced a recent shift in housing density towards more human-dominated areas are at higher risk for mortality, and the relationship between mortality risk and recent change in housing density within a home range is stronger for animals who are living in more remote areas.