Wednesday January 19, 2022
Native birds have protections in place that are not afforded to other wildlife species. Although several birds are listed under the federal Endangered Species Act or the California Endangered Species Act, most birds are also protected under the Fish and Game Code (sections 3503, 3503.5, 3513) and the Migratory Bird Treaty Act. In the United States, most native nongame birds have protections that make it unlawful to take, possess, or destroy nests or eggs. Many regulatory permits that offer protections for state or federally protected species require that nesting bird surveys be performed as part of project activities. Many permits also require more focused surveys with stricter protocols for special-status bird species that may possibly occur at a project location.
Typically, if a project plans to begin clearing vegetation or start groundwork within the nesting season, a qualified biologist will need to conduct a survey for active nests within or near the project area. California has a long bird nesting season that spans February 1–August 31 in most areas. Our wildlife team is often out conducting nesting bird surveys as well as pre-construction surveys for other protected wildlife species that may potentially occur at project sites. Nesting bird surveys include walking transects through a project area at intervals close enough to visually observe 100 percent of the habitat, and making stops to look and listen for birds around a buffer of the project area. Surveys also include searching for nesting hawks, which requires scanning a wider area, usually a half-mile buffer around the project area.
Bird nests are typically well camouflaged and not easy to find. The surveyor will watch the behavior of birds because they will often lead an observer to a nest. We watch for behaviors like courtship, nest building, copulations, mate feeding, carrying food to young, and carrying fecal sacks or eggshell from nests. We also listen for auditory clues like calls between mates and calls from chicks. Nesting bird surveys are best conducted during morning and evening hours when birds are most active.
Finding a nest doesn’t necessarily mean it is active – nests can also be completed, meaning the chicks have fledged, the nest has been abandoned, or the nest still remains from previous years. When a nest is discovered, additional observation periods may be required to determine if the nest is active or not. If an active nest is discovered, the state or federal permitting agency is notified and we prepare a nest protection plan that includes a species-specific buffer area around the nest. Swainson’s hawk and burrowing owl are two special-status species in the California Central Valley that often require more rigorous surveys to determine if there are active nests at or near a project location. These surveys involve multiple observation episodes at different stages of the nesting period to ensure no nests are present.
While conducting nesting bird surveys usually requires a lot of walking, patience, and focus, you will never hear a complaint from us because being in the field is why most of us got into this profession in the first place. Often, we are rewarded by a rare bird sighting, like spotting bald eagles nesting in a location where they haven’t been seen in a century, or observing interesting bird behavior like a loggerhead shrike impaling a western fence lizard on a twig like a reptilian shish kabob. While most of our work focuses on fish, we always appreciate our forays into the bird world.