Distribution and Habitat Associations of Three Endemic Grassland Songbirds in Southern Saskatchewan
Year: 1999
Type: article
Abstract: We conducted 1675 point counts on 93 survey routes to determine the distribution and habitat associations of three endemic grassland songbirds across the four prairie ecoregions of southern Saskatchewan, Canada. Within the four habitat types surveyed, Sprague's Pipits (Anthus spragueii) and Chestnut-collared Longspurs (Calcarius ornatus) occurred more frequently in native and seeded pastures than in hayland and cropland, whereas Baird's Sparrows (Ammodramus bairdii) occurred as frequently in hayland as in native and seeded pastures. The occurrence of Baird's Sparrows and Chestnut-collared Longspurs did not differ significantly between lightly, moderately, and heavily grazed native pastures, whereas Sprague's Pipits occurred less frequently in heavily grazed pastures. Sprague's Pipits and Chestnut-collared Longspurs occurred more often in the drier prairies of the southern portion of the province, but Chestnut-collared Longspurs were virtually absent from the cypress upland ecoregion. In contrast, Baird's Sparrows occurred most frequently in the semi-arid grasslands of the moist-mixed grassland ecoregion. In native pastures, Chestnut-collared Longspurs were associated with a lower density of short grasses and lesser amounts of litter whereas Baird's Sparrows were associated with a higher density of taller grasses and sparse shrub cover. Our results suggest that conservation programs that convert annually tilled cropland to perennial forage could provide additional habitat for endemic grassland birds. Received 2 Nov. 1998, accepted 2 April 1999. Land settlement and agriculture have greatly altered the landscape of southern Saskatchewan. Only 17% of the province's original native prairie remains (Samson and Knopf 1994) and is currently threatened by cultivation, over-grazing by livestock, invasion by exotic plant species, and urban development. In areas of Saskatchewan where soils and landscapes are particularly suited for crop production, less than 0.1I% of the original native prairie remains (Riemer et al. 1997). Despite the loss of native grassland, Saskatchewan supports a diverse grassland avifauna (Smith 1996), including 11 of the 12 primary endemic, and 17 of the 25 secondary endemic grassland bird species as outlined by Knopf (1994). Primary endemic species generally have more restricted breeding ranges (Sauer et al. 1997) and are less flexible in their habitat requirements than more broadly distributed species (Owens and Myres 1973, Knopf 1996, Davis and Duncan in press). Consequently, continental populations of 7 of the 1 1 primary endemic species are currently in decline (Sauer et al. 1997), possibly as a result of loss and degradation of native prairie habitat. Information on the habitat associations of endemic songbirds can provide insight into population declines by identifying habitat features that correlate with their occurrence. This information may be used in making management decisions and formulating land-use policies. Although many researchers have examined habitat selection by grassland songbirds (Cody 1968, Owens and Myres 1973, Whitmore 1979, Rotenberry and Wiens 1980, Johnson and Temple 1986, Mahon 1995), little research has been focused on birds of the northern mixed-grass prairie. Furthermore, most studies in the mixed-grass prairie region have been conducted on intensively managed sites (Dale 1983, Winter 1994, Madden 1996, Dale et al. 1997) or were located within a small geographic area (Arnold and Higgins 1986, Sutter 1996; but see Johnson and Schwartz 1993, Davis and Duncan in press). We examined habitat associations and the distribution of three endemic songbird species of the northern mixed-grass prairie across the entire Prairie Ecozone of southern Saskatchewan. The objectives of the study were (1) to determine whether the frequencies of occurI Saskatchewan Wetiand Conservation Corporation, 202-2050 Cornwall St., Regina SK, Canada, S4P 2K5. 2 Present address: Canadian Wildlife Service, 2004999-981h Ave., Edmonton AB, Canada, T6B 2X3. I Present address: Nature Saskatchewan, 206-1860 Lorne St., Regina SK, Canada, S4P 2L7. 4 Corresponding author; E-mail: [email protected]
Authors: Davis, S K, Duncan, David C., Skeel, M
Language: English
Topic: Avian ecology and behavior
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
SDGs: Life on land, Zero hunger
Open Access status: green
OpenAlex ID: W2499759986