The Grasshopper Sparrow is a small, inconspicuous bird, known for its buzzy, grasshopper-like song. It spends most of its winter in Mexico, and come up in late April and May to breed. We’re starting to see a great deal more of them right about now. The bird is most noticeable when males perch on top of small shrubs or wildflower stalks in the spring and early summer, singing their high-pitched songs. Grasshopper Sparrows historically have been widespread throughout the United States, but their numbers have dropped dramatically in recent years in the west. Grasshopper Sparrows once thrived in the extensive native grasslands of California, but unfortunately they are increasingly rare, and are now listed as a California Species of Special Concern. The biggest reason for the decline of the Grasshopper Sparrow is loss of native grassland habitat. Agricultural and urban developments have reduced grasslands in California, and many of the remaining grassland patches are too small and dispersed for the birds, or no longer have suitable habitat structure for Grasshopper Sparrows. Conversion of native grasslands to other crops or European annual grasses, early-summer mowing, and intensive grazing have all reduced the amount of good habitat for this species. Check out the maps below the fold to see the progress of their migration into the United States this spring (photo by Greg Smith):

At the end of March, we were just starting to see Grasshopper Sparrows appear in its breeding range. As you can see, the larger number of birds were accumulating in the eastern United States:

In this map from yesterday, you can see the birds appearing is vastly greater numbers. And, of course, you can see the exploding population in the east: