ABSTRACT
Grasshopper sparrows arrive on their breeding grounds, usually short to mid-grass prairie, but also on agricultural areas and recently reclaimed surface mines, in late March to mid April where, after a few days, they become territorial and conspicuously sing from exposed perches. They depart for wintering grounds during mid September to late October. In southwestern North America several species of grassland sparrows may remain year-round, although they are not territorial in the winter. The most accepted method for censusing breeding grasshopper sparrows is "territory flush" technique. Censusing grasshopper sparrows during the nonbreeding season is more challenging and usually either a belt transect or line transect is used. The major strength of the technique is that, while it is time consuming, an accurate description of the number of territorial males on a site can be determined and an absolute density can be derived.
