Variation in passerine use of burned and hayed planted grasslands

Abstract

ABSTRACTCreation of grassland communities is a popular approach to conserve grassland‐nesting waterfowl and songbirds. Much uncertainty remains regarding the most appropriate seed mixtures and the type and frequency of management. We conducted line‐transect songbird surveys in grasslands converted from cropland to native and tame grass‐forb mixtures and managed by burning (native only) or haying (native and tame) in Saskatchewan and Manitoba, Canada. Fields were 1–9 years post‐management (YPM). Our objective was to improve our understanding of the effects of management regime (native hayed, native burned and tame hayed fields) and frequency (YPM) on passerine density and occurrence in planted grassland. We found limited support for an effect of management regime on passerine density and occurrence in both provinces. Vesper sparrow (Pooecetes gramineus) occurrence in Saskatchewan was greatest in tame hayed fields, and clay‐colored sparrow (Spizella pallida) density in Manitoba was greater in tame hayed fields than in native burned fields up to 5 YPM. Years post‐management most strongly influenced the occurrence of vesper sparrows in Saskatchewan and sedge wrens (Cistothorus platensis); common yellowthroats (Geothlypis trichas); clay‐colored, Savannah (Passerculus sandwichensis), Le Conte's (Ammodramus leconteii), and Nelson's (A. nelsoni) sparrows; and bobolinks (Dolichonyx oryzivorus) in Manitoba. Five of the 8 species influenced by YPM exhibited a year‐dependent non‐linear response such that they reached their greatest density 4–5 YPM. Our results indicate that the type of stand (native or tame) or management (burning or haying) matters little to the grassland songbird community occupying planted cover fields and that the frequency of management will likely depend upon local environmental conditions in a given region or year. Some form of management of planted grasslands, however, should occur every 4–6 years to maintain habitat for a number of generalist grassland species. © 2017 The Wildlife Society.