The Impacts of Recreational Infrastructure on Mammal Use of Riparian Zones in Northern California Regional Parks
Abstract
Public lands have been important for the protection of riparian habitats; however, many public lands are also used for recreation, which can reduce mammal habitat use. Understanding how mammals are affected by recreation in riparian areas can help guide management decisions. The goal of this research is to understand the effect of recreation on mammal use of riparian habitats in two popular East Bay Regional Parks, Charles Lee Tilden and Wildcat Canyon, and to map the extent of that impact. Cameras were deployed in the riparian areas of a high, moderate, and low development site (Alvarado, Tilden, and Wildcat Canyon) for two seasons to observe mammal activity. GIS was used to map the distribution and impacts of recreational infrastructure. Human activity was greatest at Alvarado and then Tilden and was very low at Wildcat Canyon. Mule deer and bobcats were seen less frequently at sites with more recreation. Observations mule deer higher at night in busy parks and negatively correlated with people. The observation frequencies of coyotes and urban adapted species were highest at Tilden and Alvarado, respectively. The maps showed that infrastructure was concentrated around creeks, resulting in 21.48% of the riparian zone impacted by non-trail features and 70.02% was impacted by trail. To protect sensitive species, managers should reduce trail density and refrain from expanding infrastructure into undeveloped areas like Wildcat Canyon.
