Monday, November 25, 2019

Catching Up With Our California Endemic: The Yellow-billed Magpie

I see them pretty much every day, so it's easy sometimes to forget that this is an exceedingly rare bird. There are less than 200,000 of them in the world, which is not all that many for a species that is faced with habitat loss, and an exotic disease. The Yellow-billed Magpie (Pica nuttalli) is also one of California's few endemic bird species.

If you are a non-Californian, you might look at this species and think it is just a magpie (the Black-billed Magpie), but it is a distinct species, and the ranges of the birds rarely overlap. The Sierra Nevada is the barrier that has provided the isolation allowing the species to diverge.
I live and work in prime magpie habitat. They range over the Coast Ranges and Central Valley of California, living off of bugs, grains, and pretty much any kind of food they can find. They are gregarious, often flying about in flocks, and engaging in boisterous arguments. A day at work would be lonely without their calls going on in the background.

The arrival of the West Nile Virus was nearly their undoing in the early 2000s. They were particularly susceptible to the viral infection because of their gregarious nature, and more than half of them were lost. The few birds with natural resistance have survived and have allowed the population to slowly rise again.
These pictures are some I've collected this year from the MJC West Campus and the along the Tuolumne Parkway Trail where I most often see the birds. I'm glad they survived their version of the bubonic plague. The state would be a less interesting place without them.

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