The implications of habitat management on the population viability of the endangered Ohlone tiger beetle (Cicindela ohlone) metapopulation

PLoS One. 2013 Aug 12;8(8):e71005. doi: 10.1371/journal.pone.0071005. eCollection 2013.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Biodiversity*
  • California
  • Coleoptera*
  • Conservation of Natural Resources
  • Ecosystem
  • Endangered Species*
  • Female
  • Models, Theoretical
  • Population Density
  • Population Dynamics

Grants and funding

Full funding for Open Access was provided by the University of California Santa Cruz Open Access Fund. TMC was supported by The Robert and Patricia Switzer Foundation (http://switzernetwork.org/) and NSFGK-12 DGE-0947923 (to G. Gilbert, I. Parker, D. Ash) (http://scwibles.ucsc.edu/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.