Technical Memorandum: Patterns of Vehicle-Based Vertebrate Mortality in the Ballona Wetlands Ecological Reserve

Over the past decade, concerned stakeholders anecdotally noticed a high frequency of animal kills along the major roadways adjacent to the Ballona Wetlands Ecological Reserve (“BWER” or “Reserve”) (L. Fimiani, personal communication, 2011).

This memorandum was developed to quantify the vertebrate mortality along Reserve-adjacent roadways. Additionally, it will provide information and data to the ongoing CEQA process regarding wildlife-vehicle collisions and subsequent direct vertebrate mortality through surveys conducted along roads bisecting the BWER from 2010-2013.

City of Los Angeles traffic-count data across a 24-hour interval during the week calculated that approximately 20,000-60,000 cars travel along roadways bisecting and adjacent to the Reserve, including Culver Boulevard, West Jefferson Boulevard, and Lincoln Boulevard (CoLA 2014). High traffic volumes combined with 45 mile per hour (mph) speed limits may pose significant risks to wildlife within the BWER. Analyzing these data may help evaluate opportunities to minimize or reduce harm and impacts to fauna, as well as reducing hazards to drivers.

Specific survey goals included:

  1. Comparison of vertebrate mortality along three road transects bisecting the Reserve
  2. Identification of animal type most vulnerable to vehicle-based mortality
  3. Identification of locations demonstrating higher frequency wildlife-vehicle collisions (“hotspots”).