Menu

Pumas on the Edge: The Effects of Human Activity and Development

Post submitted by Max Allen of the Santa Cruz Puma Project.

A puma family above the nighttime lights of San Jose (Photo courtesy of Chris Fust)
A puma family above the nighttime lights of San Jose (Photo courtesy of Chris Fust)

I currently work on the Santa Cruz Puma Project in California, studying pumas that live in the highly fragmented and human-dominated Santa Cruz Mountains. Pumas who live here must navigate through a landscape that is a mosaic of different levels of human activity and housing density alongside open spaces, entailing risk during run-ins with humans. The northeastern border of our study area is Silicon Valley, an area of a high density of humans and development, but human growth and development is accelerating throughout the Santa Cruz Mountains. Having previously studied pumas in a remote area in northern California, I am often surprised by the juxtaposition of a large carnivore living so close to so many people in our study area.

GPS locations of 20 pumas in our study area between Santa Cruz and San Jose (Figure courtesy of Wilmers et al. 2013)
GPS locations of 20 pumas in our study area between Santa Cruz and San Jose (Figure courtesy of Wilmers et al. 2013)

As you might expect, our research shows that pumas avoid areas with the most development (Wilmers et al. 2013), and areas with the most human activity (Wang et al. 2015). Juveniles seem to have the hardest time. When kittens are around 1.5 years old, they disperse, meaning that they leave their mother’s home range in search of territory of their own. Generally, the high quality territories are already occupied by adult resident pumas, and since juveniles are not ready to control prime habitat, they are often pushed by the resident animals into marginal, suboptimal habitat. In our case, this means areas closer to higher levels of human activity and development.

The yearling pumas in this video will disperse from their mother soon, and likely live in sub-optimal habitat along the edges of cities (Video by Max Allen)

Because juveniles often live along the edges of human development, they are susceptible to wildlife-human conflicts or other sometimes surprising incidents involving humans. We documented a foray into downtown San Jose by one of our juvenile male pumas, where he surprisingly slept outside of a parking garage during the busy day (Wilmers 2014). Sadly, this puma continued to spend the his time along the margins of development, and five months after his adventure in San Jose was killed by a collision with a vehicle on highway 280.

One key finding of our research is that not all puma behaviors are affected equally by human development (Wilmers et al. 2013). Pumas appear to be surprisingly adaptable to human development when hunting and moving across the landscape. On the other hand, nurseries and communication areas are heavily affected, and are only found in areas far removed from human development.

Nurseries and communication areas are incapable of coexisting near human development (Photo by Max Allen)
Nurseries and communication areas are incapable of coexisting near human development (Photo by Max Allen)

The location of dens suggests that young pumas dependent on their mothers have increased risk from human activity and development. This is the life stage that generally exhibits the lowest survival rates among pumas (Logan and Sweanor 2001), and their survival may be further compromised by human development. With the human population and development in the Santa Cruz Mountains predicted to grow, we don’t know what the future holds for the puma population in the Santa Cruz Mountains.

Our study area is noted for its progressive conservation mindset, highlighted by many preserved lands, which likely allows for a puma population to exist in this highly fragmented habitat. Many conservation projects are in the works as well, including a bypass underneath Highway 17 by the Santa Cruz Land Trust, and our research was used to determine optimal placement for puma movement. This is especially important as projections of future development suggest that habitat will become more fragmented in the future.

 

Data from our GPS collars on pumas identified Laurel Curve as the ideal place for an underpass on California Highway 17 (Photo courtesy of Steve Mandel)
Data from our GPS collars on pumas identified Laurel Curve as the ideal place for an underpass on California Highway 17 (Photo courtesy of Steve Mandel)

Understanding the effects of human development and activity on puma behavior and survival are one of my ongoing subjects of research. Keep up to date with my research and our project at https://www.facebook.com/santacruzpumas.

References:

Logan, K., and L. Sweanor. 2001. Desert puma: evolutionary ecology and conservation of an enduring carnivore. Island Press: Covelo, CA.

Wang, Y., M.L. Allen, and C.C. Wilmers. 2015. Mesopredator spatial and temporal responses to large predators and human development in the Santa Cruz Mountains of California. Biological Conservation 190: 23-33.

Wilmers, C.C. 2014 A detailed look at 46m’s journey from Big Basin to Mountain View. http://santacruzpumas.org/2014/05/08/a-detailed-look-at-46m-s-journey-from-big-basin-to-mountain-view-mvpuma/

Wilmers, C.C., Y. Wang, B. Nickel, P. Houghtaling, Y. Shakeri, M.L. Allen, J. Kermish-Wells, V. Yovovich, and T. Williams. 2013. Scale dependent behavioural responses to human development by a large predator, the puma. PLoS One 8: e60590.