Comparative ecology of horned lark Eremophila alpestris flava Gm. and snow bunting Plectrophenax nivalis L. in subarctic and arctic zones

Abstract

The ecological features of snow buntings and horned lark have been discussed; their ecology has so much in common that they are the only representatives of the Passeriformes order in polar deserts and arctic tundra. Under the current climate conditions of the Arctic, there is no northern range limit for snow buntings. The limit of the horned lark northern range is determined by the minima of biotopic, food supply, and temperature factors; these factors allow the horned lark to penetrate the Arctic zone, though not to occupy a considerably large part of it. Southern limits of distribution of horned larks and snow buntings are probably determined by the light regime in the region, since outside the polar day zone the birds are unable to enter a state of reproductive activity. An additional requirement for the nesting habitat of snow buntings is an average July temperature below 10°C.