The Northern Harrier is a slender, medium-sized raptor recognized by its distinctive white rump and its low, coursing flight behavior. Closely associated with grasslands and fresh- and salt-water marshes, Northern Harriers are common during the winter and spring/fall migration periods, but are relatively uncommon in the Central Valley during the breeding season. However, the Central Valley supports the largest breeding population in California (Davis and Niemela 2008). They nest on the ground and require adequate cover to conceal their nests from predators (MacWhirter and Bildstein 1996). Ricelands in the Central Valley provide an important wetland substitute for this species. Harriers often hunt for small shorebirds, songbirds, and rodents concentrated in flooded and disked rice fields, as well as in fallow fields that support high densities of voles and other prey (Wilkison and Debban 1980). One hundred seventy-five Northern Harriers were observed in rice fields and grasslands during the 2002 Lincoln Christmas Bird Count. This count was tied for the seventh highest of more than 1,900 counts conducted throughout the continent and, as such, highlights the importance of rice fields as winter foraging habitat.
The Northern Harrier is on the California Bird Species of Special Concern Priority 3 list, primarily due to loss or degradation of breeding habitat (Davis and Niemela 2008).
Northern Harrier 1,2,3: Leslie Morris