Mapping Roadkill Spots in California

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There are some parts of the United States where mapping roadkill is an important part of the scientific community. Volunteers and paid researchers map evidence of roadkill and log it in a database to track where wildlife are crossing roads, what species they are, how many are killed per year, and what kind of accidents occur around them.

For Californians, driving is a way of life. The highways are jam-packed with residents and visitors looking to get off at the next exit or escape into the hills for some much needed fresh air and time away from the city.

Unfortunately the encroaching suburbs are displacing a record number of animals out of their traditional habitats; as their ground is lost to subdivisions and roads, animals are (literally) taking to the streets with often disastrous consequences.

Road sign cautioning for the presence of  deer.
Deer sign. Photo: John Cleckler/USFWS

California Roadkill Observation System

The California Roadkill Observation System, or CROS, is a volunteer-run website that has documented over 30,000 instances of roadkill since its inception. The database is then used by researchers and conservationists looking to explore the effects of urbanization on California’s wildlife populations and where they are at increased risk of coming into contact with humans.

By tracking roadkill statistics they can find out where animals are the most likely to be killed, in what locations, and what species are most at risk. This data can lead to changes in conservation policy by the California state government to include more wildlife crossings over highways and a better perspective on how humans are influencing the ecological environment around them.

Unfortunately roadkill numbers don’t indicate some other important factors that policy makers need to know in order to enact change; for instance, what percentage of animals do make it across a road? Where have roads intersected animal habitats? How many animals would a wildlife corridor save?

The CROS database does provide everyday people with the tools to interact with the environment around them. The data collected covers as wide a range as volunteers are willing to go, and although some locations are missing consistent data, other places have abundance.

California Roadkill Observation System (CROS) - Map of Roadkill.
California Roadkill Observation System (CROS) – Map of Roadkill.

There are many benefits to the kind of volunteer-run research like the California Roadkill Observation System, among them the ability for researchers and conservationists to collect valuable data about the interactions between humans and animals in this highly trafficked part of the world.

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