The savannah sparrow territorial system: can habitat features be related to breeding success?

Abstract

We studied the biology of the savannah sparrow (Passerculus sandwichensis) in a tidal marsh – abandoned fields ecotone at Isle Verte, Québec, from 1976 to 1981 in an attempt to relate habitat features of the territories (size, vegetation structure and height, food abundance, and an index of foraging opportunities) with breeding success (success in attracting a mate and in fledging at least one young). The height of plant cover did not influence the selection of nesting areas by females. The index of foraging opportunities was highly variable and could not be related to the age of the territory holder (yearling or older), his mating status (breeder or bachelor), or to his breeding success (success in fledging at least one young). Territory size was not consistently influenced by these factors. We propose several reasons for the lack of relation between breeding performance and those features of habitat quality that we studied.