What’s An Avostilt?

(Recurvirostra americana) American Avocet nest at the Saltworks at South San Diego Bay NWR. San Diego County, California USA 2009-05-20.

I’ll never forget when in 2003 I first heard the expression “Avostilt”. The San Diego County Bird Atlas needed images of Elegant Terns and author Phil Unitt introduced me to the biology team monitoring the tern colonies at the south end of San Diego Bay. Elegant Terns had recently colonized the narrow dams separating the evaporation ponds. Joining their survey exposed me to intimate encounters with Elegant, Gull-Billed, Forster’s and Least Terns, with skimmers, cormorants, Belding’s Savannah Sparrows, Killdeer, American Avocets and Black-Necked Stilts; all species that nest at the area we call the Saltworks.

The walks were brisk while the team recorded observations about the nests we passed. Tern nests were important to document, but not so much the shorebirds who shared the nesting grounds. Tern nests were always at the highest places on the dams, with stilt and avocet nests lower and very near the waterline of these saline ponds. I carried my camera gear, walking the water’s edges, as to avoid the possibility of landing my big feet on the tern eggs. Black-Necked Stilt nests and eggs look very much like American Avocet nests and eggs. The biologist reported these nests in their logs, calling out “Avostilt”. They could have analysed the nests and rendered a precise ID, but it would have cost valuable time and not captured any useful scientific data. To this day, whenever it is my pleasure to spend time with these biologists, I try to bring up “Avostilt” in the conversation, with a wink in my eye.