|Jenner Headlands. Photo by Ryan DiGaudio / PRBO.|
With the cows behind me, I pause to appreciate the panoramic scene just as the sun crests the mountains to the east. Before me is a verdant slope of grass speckled with wildflowers, rolling down to the mouth of the Russian River and the Pacific Ocean 1,000 feet below. Scanning the rugged coastline miles to the south, past Goat Rock and Bodega Head, I can make out the silhouetted arm of Point Reyes reaching for the horizon. The dawn chorus of singing Savannah and Grasshopper sparrows remind me it’s time to start work!
Given this beautiful setting—and its proximity to private subdivision and ranchette developments—it’s easy to understand what motivated the Sonoma Land Trust1 to purchase the 5,630-acre Jenner Headlands property in 2009. The acquisition protected 12 habitat types, 8 watersheds, 8.5 miles of streams, 3,100 acres of redwood and Douglas fir forest, 1,500 acres of rare coastal prairie grassland, and many special-status species.
|Ryan DiGaudio. Photo by Khara Strum.|
My mission here is to collect data on the property’s grassland bird population. The two most common grassland birds nesting at Jenner Headlands are the “Bryant’s” Savannah Sparrow and the Grasshopper Sparrow, both listed as California Bird Species of Special Concern. Fortunately for these and other at-risk species, their habitat at the Jenner Headlands is now protected from private development. Protection alone, however does not guarantee the long-term ecological health of their habitat.
Management decisions, such as whether or not to continue livestock grazing, can have a significant impact on the property’s grassland birds. The data I’m collecting today can be used as a benchmark for gauging future population changes. With focused monitoring, we can evaluate how changes in management practices affect bird populations over time, thereby providing a feedback mechanism for informing management decisions—a process known as adaptive management. Preliminary results suggest that for this particular site some livestock grazing may benefit these grassland birds. However, without more study it’s impossible to identify an optimal grazing strategy, let alone accurately predict how changing the current grazing practices would impact these birds. So following adaptive management principles—namely, a strong feedback loop between on-the-ground practices and ecological monitoring to assess the results—will be key for maintaining or improving the habitat for grassland birds at Jenner Headlands.
At the end of the day, I trudge back to the top of the hill where I parked my car. Once again an obstinate herd of cows blocks my path. Rather than ask politely as I did in the morning, I assertively order the cows to step aside—and it works. Adaptive management on an entirely different level! I may become a cow whisperer yet.