Measuring the health of Mt. Tam

Maintaining a healthy, vibrant and diverse Mt. Tam begins with understanding how key ecological resources are faring, and how we can better care for this iconic and beloved place.

One Tam partners and Bay Area scientists have come together to try to answer the question: How healthy are Mt. Tam's natural resources?

Oak Woodland Birds

Oak Woodland Birds

Photo by Nagarajan Kanna

Summary

The overall condition of oak woodland-associated birds is Good.

Point Blue Conservation Science analyzed patterns of abundance from 1996 to 2013 to determine the trends for as many individual species as possible (see References below). We were able to determine trends for five of the eleven oak woodland-associated species. Trend for the American Kestrel was determined based on unpublished information from the Golden Gate Raptor Observatory and Audubon’s Christmas Bird Counts.

While the condition rating is Good, we lack sufficient information to determine trends for five species. Another species, the Western Scrub-Jay, showed significant declines. The reason for this decline is unknown but the timing corresponds with the emergence of West Nile Virus and Sudden Oak Death, to which this jay may be particularly susceptible. Because this species plays an important role in acorn dispersal, and hence overall condition of oak woodlands, continued ongoing monitoring is essential to determine when active management might be needed.

Condition, Trend, and Confidence for Oak Woodland Bird Species Included in This Analysis

Resources

Links
Point Blue Conservation ScienceGolden Gate Raptor ObservatoryMarin Audubon Christmas Bird Count
Downloads
Abundance Patterns of Landbirds in the Marin Municipal Water District: 1996 to 2013

Learn More

References:

Cormier, R.L., Seavy, N.E. & Humple. D.L. (2014). Abundance patterns of landbirds in the Marin Municipal Water District: 1996 to 2013. Point Blue Report. Available here.