COS 25-6 - Beach Lions, Coyotes, and Bears, Oh My! The Role of Mammalian Consumers in Marine to Terrestrial Resource Subsidies

Abstract: Animal-vectored subsidies–the animal-mediated movement of resources across habitat boundaries–drive ecological processes in both donor and recipient ecosystems. However, human barriers to animal movement (e.g. roads) often alter the delivery and receipt of resource subsidies. The Southern California coastline once potentially benefited from marine to terrestrial subsidies, with nutrients from productive kelp forests flowing to relatively low productivity beach and coastal scrub habitats. However, 55% of the Southern California coast is developed, and the fauna historically responsible for vectoring such resources inland are potentially unable or unwilling to move freely across much of the coastal ecotone. We developed Project ECOTONE - Energetic Connectivity of Terrestrial and Oceanic Nearshore Ecosystems - to understand baseline movement of consumers between intertidal habitats (beaches, rocky intertidal, and marshes) and adjacent terrestrial ones by implementing an array of motion-triggered trail cameras along access-restricted coastlines in Santa Barbara County, CA (Vandenberg Space Force Base and the Jack and Laura Dangermond Preserve). These cameras captured evidence that, in the relative absence of human activity, terrestrial consumers–most commonly coyotes, deer, and feral pigs–regularly forage in intertidal habitats. Future aims of this study include determining the sensitivity of foraging to seasonal changes and to human activity. This research is expected to provide essential baselines for management of Southern California’s last remaining “wild coast”.