When we talk about bird migration, we tend to speak in terms of north and south (ie, north for the spring, south for the winter). But with every good rule, there are exceptions. And for us in California, some of those exceptions are huge. some birds don't migrate at all, some birds just go to different altitudes, some birds fly off in all kinds of different directions. As Andrea Jones, our Important Bird Areas director says, “On the East Coast, migration is so simple. When things freeze, the birds head south. When it thaws, the birds come back. Here on the West Coast, it’s just totally crazy.” Take the Mountain Plover, the so-called “Ghost of the Plains.” This shorebird that rarely if ever sees the seashore doesn’t head north in the spring. Instead, it heads east to breeding areas in Colorado, Montana and Wyoming. The photo of a Mountain Plover above was taken by Gary Woods recently in California. Note the band on the leg. That band indicated that the bird was actually banded at the bird's breeding ground in Colorado (larger version of the photo below) Look at the maps below to see this bird's migratory pattern illustrated a little more clearly.

Below is an eBird (you're using eBird, right?) map showing observations of Mountain Plover in January.

This distribution will look pretty consistent until the beginning of April, when the birds will all start heading west. Here's the map from April of last year, which shows where all the birds are headed:

The Mountain Plover is a key species for conservation. Due to a number of factors, including habitat loss, the bird's numbers have been dropping precipitously in recent year. A survey conducted by Audubon California and the U.S. Fish & Wildlife Service last year shows a steep decline, and a subsequent ruling not to place the bird on the Endangered Species List marked greater challenges ahead for the bird. This year, Audubon California was in the field again surveying for the bird. The results of that research will be available soon.