Naturalist’s Notebook: Yellow-rumped Warblers at a Sapwell

1 December 2010
Tillie Creek Campground
Kern County, California

Upon checking one of the many sapsucker trees, I found a wintering Yellow-rumped Warbler happily plundering some freshly drilled sap wells. But when two White-breasted Nuthatches arrived, the warbler immediately attempted to drive them away, which proved to be a futile endeavor. Unlike other dedicated sap-well raiders such as Ruby-crowned Kinglets and Anna’s Hummingbirds—which easily give way to the tyrannical warblers—the nuthatches would not be driven away.

For the next three or four minutes, the warbler would chase one and then the other of the nuthatches in fast pursuits that wound and whirled in and out of the blue oak’s canopy and through the neighboring gray pine.

Of course, every time the warbler pursued one nuthatch, the other nuthatch would casually visit the many rows of sap wells.

Inevitably, the warbler’s pursuits degraded to merely annoying, short, halfhearted chases with no hope of driving the nuthatches away from the contested sap wells.

But when the Red-naped Sapsucker returned to reclaim its sap wells, the raiders quickly retreated before its swift series of attacks, which swept all of them away.