southern california biological services
cowbird trap
Welcome to TW Biological Services

TW Biological Services is a Southern California Environmental Consulting firm specializing in Brown-Headed Cowbird trapping and biological surveys and population monitoring of sensitive and endangered species, including the Least Bell's Vireo, California Gnatcatcher, and Southwestern Willow Flycatcher. In addition we also provide general wildlife species surveys, sensitive habitat assessment, habitat restoration monitoring, construction project compliance, and cowbird trap construction.

Established in 1994 by Jennifer Sexton (formerly Jennifer Turnbull) TW Biological Services provides biological consulting services throughout Southern California. Our clients include private companies, the United States Military, and public agencies at the federal, state, and local levels.

Services we Provide

brown headed cowbird trappingTW Biological Services specializes in native songbird conservation in Southern California through survey and monitoring, and Brown-headed Cowbird trapping.  Since 1997, we have routinely managed trapping projects ranging up to 40 traps on a single project.  We provide a full suite of related services including initial habitat assessment relative to trap location, interaction with local agencies and landowners, and coordination as necessary with other members of the environmental project team.  We can provide durable traps on either a temporary or permanent basis.

Click the “Services” link above for a more detailed discussion of the services we offer.

Experienced In...

southern ca habitat restoration
Habitat assessments, restoration monitoring, construction compliance. We maintain all of the necessary permits from the U.S. Fish and Wildlife Service and CA Department of Fish and Wildlife to survey and monitor wildlife and perform bird and Raptor surveys.  We conduct habitat assessments with an emphasis on sensitive species management.

We provide consulting biological services in support of restoration monitoring on construction projects to avoid and/or minimize impacts to sensitive natural resources.


usmc contractorOur impressive project list includes the U.S. Marine Corps Camp Pendleton, U.S. Army Corps of Engineers, U.S. Navy, U.S. Fish & Wildlife Service, U.S. Forest Service, City of San Diego, as well as many other businesses and organizations.

TW Biological Services routinely participates in the government contract and bidding process both as a prime contractor, and on a sub-contract basis as a member of a bidding team.  We pride ourselves on our efficiency in response, and our ability to work seamlessly as part of an environmental team.