The implications of habitat management on the population viability of the endangered Ohlone tiger beetle (Cicindela ohlone) metapopulation.
Despite their role in providing ecosystem services, insects remain overlooked in conservation planning, and insect management approaches often lack a rigorous scientific basis. The endangered Ohlone tiger beetle (Cicindela ohlone) occurs in a 24-km(2) area in Santa Cruz County, California. The once larger metapopulation now consists of subpopulations inhabiting five patches of coastal prairie where it depends on bare ground for mating, foraging, and oviposition. Human activities have eliminated natural disturbances and spread invasive grasses, reducing C. ohlone's bare-ground habitat. Management actions to restore critical beetle habitat consist of cattle and horse grazing, maintaining slow bicycle speeds on occupied public trails, and artificial creation of bare-ground plots. Recreational biking trails help maintain bare ground, but can cause beetle mortality if left unregulated. We tracked C. ohlone survivorship and estimated fecundity for three years. We then constructed a stage-structured population projection matrix model to estimate population viability among the five patches, and to evaluate the success of management interventions. We demonstrate that habitat creation, regulation of bicycle speed, and migration between patches increase C. ohlone survival and population viability. Our results can be directly applied to management actions for conservation outcomes that will reduce species extinction risk and promote recolonization of extirpated patches.
Environmental Studies Department, University of California Santa Cruz, Santa Cruz, California, USA. tara.cornelisse@gmail.com
Tara M
TM
Cornelisse
Michelle K
MK
Bennett
Deborah K
DK
Letourneau
D000818:Animals; D044822:Biodiversity; D002140:California; D001517:Coleoptera; D003247:Conservation of Natural Resources; D017753:Ecosystem; D056727:Endangered Species; D005260:Female; D008962:Models, Theoretical; D011156:Population Density; D011157:Population Dynamics