Survival and Mortality of Pumas (Puma concolor) in a Fragmented, Urbanizing Landscape

Abstract

Wide-ranging large carnivores pose myriad challenges for conservation, especially in highly fragmented landscapes.Over a 13-year period, we combined monitoring of radio collared pumas with complementary multi-generational genetic analyses to inform puma conservation in southern California. Our goals were to generate survivorship estimates, determine causes of mortality, identify barriers to movement, and determine the genetic and demographic challenges to puma persistence among >20,000,000 people and extensive urban, suburban, and exurban development. Despite protection from hunting, annual survival for radio collared pumas was surprisingly low (55.8%), and humans caused the majority of puma deaths. The most common sources of mortality were vehicle collisions (28% of deaths), and mortalities resulting from depredation permits issued after pumas killed domestic animals (17% of deaths). Other human-caused mortalities included illegal shootings, public safety removals, and human-caused wildfire. An interstate highway (I-15) bisecting this study area, and associated development, have created a nearly impermeable barrier to puma movements, resulting in severe genetic restriction and demographic isolation of the small puma population (~17-27 adults) in the Santa Ana Mountains west of I-15. Highways that bisect habitat or divide remaining "conserved" habitat, and associated ongoing development, threaten to further subdivide this already fragmented puma population and increase threats to survival. This study highlights the importance of combining demographic and genetic analyses, and illustrates that in the absence of effective measures to reduce mortality and enhance safe movement across highways, translocation of pumas, such as was done with the endangered Florida panther, may ultimately be necessary to prevent further genetic decline and ensure persistence of the Santa Ana Mountains population.

Densities and perceptions of jaguars in coastal Nayarit, Mexico

“…The ability of some large carnivores to inhabit heavily altered landscapes is widely recognized in many temperate ecosystems (Linnell et al , Basille et al , Vickers et al ), but is virtually undocumented in the Neotropics. Our results add to an increasing body of evidence demonstrating the value of multiuse landscapes as complements to protected areas for large carnivore conservation.…”

“…The projected route of the highway bisects our camera‐trap polygon, threatening the persistence of jaguars in the SBM. Jaguars, especially females, in southeastern Mexico displayed strong aversion to paved roads (Colchero et al ), which are one of the greatest threats to large carnivores because they increase mortality through vehicle collisions and cause demographic isolation by inhibiting movement between populations (Noss et al , Vickers et al ).…”

Puma response to the effects of fire and urbanization

“…These areas of moderate human population densities where adequate natural vegetative cover can burn have been correlated with the largest spikes in ignitions and fire frequencies (Syphard et al , ). As more of these habitats become degraded and fragmented, pumas will become more constrained in their movements and face the additive threats of mortality from roadways, depredation (Burdett et al , Vickers et al ), and further loss of genetic variability (Ernest et al ).…”

“…Pumas ( Puma concolor ) are the ecosystem's largest predator with wide‐ranging movement behaviors and a high level of sensitivity to habitat fragmentation (Crooks ), and they serve as an indicator species for ecosystem integrity (Ripple and Beschta , ; Thorne et al ). There is a growing concern that persistence of puma populations in southern California is uncertain with previous studies reporting pumas are becoming genetically isolated from each other (Ernest et al , ; Riley et al ; Vickers et al ), and immigration into these populations is necessary to prevent extirpation from the region within the next 100 years (Beier ). We focused on this region as development pressure threatens to transform nearly 10% of the study area from suitable to unsuitable puma habitat by 2030 (Burdett et al ).…”

Aligning mountain lion hunting seasons to mitigate orphaning dependent kittens

“…Harvest is the strongest driver of mountain lion population dynamics wherever hunting is practiced, and anthropogenic causes remain a significant source of mortality even where hunting is not allowed (Cooley et al , Thompson et al , Vickers et al ). Accordingly, conservation scientists and wildlife managers are beginning to address the indirect effects of hunting to improve management practices and expand our ability to predict the cascading effects of management decisions such as hunting quotas (Frank et al ).…”