Cheadle Center for Biodiversity and Ecological Restoration

This poster was presented at the UCSB EEMB research symposium in 2024.

Seed predation by granivores limits plant survival and recruitment of new germinates, especially of rare species limited by small populations and increasing pressure from nonnative invasives. The relationship between granivores and native flora at the Dune Protected Area in Callandar, CA is currently shifting away from historic patterns; Nipomo  mesa lupine (L. nipomensis) and other dune stabilizing plant species have been impacted by the habitat-wide colonization by the invasive perennial veldt grass (Ehrharta calycina). Current veldt management practices prevent the use of herbicide to control the grass within a 15-foot buffer of extant lupine populations. Understanding how dense stands of veldt grass may support increased populations of L. nipomensis seed predators can inform the management of veldt grass and the recovery of the endangered lupine. This study assessed seed predation through low profile boxes baited with L. nipomensis seeds and camera traps capturing both video and still images to compare seed predation rates relative to dense stands of veldt grass. Conservation implications were further assessed by considering the role of cages (fencing) in reducing seed predation.  We found that increased proximity to veldt grass modestly increased seed predation, and that uncaged bait stations lost the most seeds (~70% loss rates compared to ~15% in caged plots). The most common seed predators captured on camera were Heermann’s kangaroo rats, Dipodomys heermanni (found outside of cages and away from veldt grass), Deer mice, Peromyscus maniculatus (found outside of cages and adjacent to veldt grass), and California towhees (found within cages and away from veldt grass). Our results establish patterns of seed predation consistent with predicted results and emphasize potential vulnerability to seed predation in areas near veldt or areas unprotected by caging.