They prefer areas with sparser vegetation than those chosen by the chestnut-collared longspur. Plectrophenax is a small genus of passerine birds of the longspur family Calcariidae. The species also mated with a Lapland Longspur creating a hybrid. McKay's bunting ("Plectrophenax hyperboreus") is a passerine bird in the longspur family Calcariidae. During the winter, the longspur feeds on seeds. Smith's and the chestnut-collared longspur were each other's closest relatives (sister taxa). The chestnut-collared longspur ("Calcarius ornatus") is a species of bird in the family Calcariidae. The Lapland longspur is a robust bird, with a thick yellow seed-eater's bill.