 However, the handful or so subspecies in this complex are poorly differentiated even morphologically for the most part; a two-subspecies arrangement recognizing the rather distinctive "altivagans" (the northern form) as distinct from the southern populations ("schistacea") might be more reasonable (Rising & Beadle 1996).As with red and sooty fox sparrows, slate-coloreds also prefer to build their nests on the edges of wet habitat but are much less picky about in which plant they build.Their call note is sharp "klink" according to Rising & Beadle (1996), or "a sharp "smack", like Sooty and Red populations" according to Sibley (2000).