Tracking data reveals egret’s 98-mile nighttime flight to Sierra Nevada foothills

Tracking data reveals egret’s 98-mile nighttime flight to Sierra Nevada foothills

Map above shows GPS location points gathered from a female Great Egret from 8/14/17 through 8/17/17.

Since outfitted with GPS tracking devices in mid June, the three Great Egrets (one male and two females) tagged near Toms Point on Tomales Bay have remained in northern Marin and southern Sonoma counties. But on the evening of August 14, at around 7:20 p.m., a female identified as GREG 3 lifted off from Chileno Valley and started flying east. She stopped for about a half hour in some cypress trees southeast of Petaluma, then, just as darkness fell, she took flight again. She flew east through pre-moon darkness, skirting the San Pablo Bay, then crossing the Sacramento-San Joaquin Delta and the Central Valley. At around 11:00 p.m. she landed along Dry Creek, between the towns of Galt and Ione.

GREG 3 spent the next day (August 15) foraging along the creek and also visiting some nearby agricultural fields.

This flight covered approximately 98 miles, and took a bit over 3.5 hours to complete, for an average flight speed of around 28 miles per hour. It is really interesting that this flight took place at night, and that she took such a direct route, suggesting very intentional use of a large landscape and perhaps indicating that she has made this same trip before.

This fascinating new information about how these iconic birds use the varied habitats throughout central California will help us guide conservation of these species and the ecosystems they rely on.

ACR’s Heron and Egret Telemetry Project is the first GPS tracking study of its kind in the Western U.S. Learn more:

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