Effects of fire and grazing on grasshopper sparrow nest survival
Document Type: Journal Article
Author(s): Torre J. Hovick; James R. Miller; Stephen J. Dinsmore; David M. Engle; Diane M. Debinski; Samuel D. Fuhlendorf
Publication Year: 2012

Cataloging Information

  • Ammodramus savannarum
  • brown-headed cowbird
  • competition
  • cover
  • daily survival rate
  • fire management
  • fire suppression
  • grasshopper sparrow
  • grassland
  • grazing
  • Great Plains
  • Iowa
  • Molothrus ater
  • mosaic
  • nest success
  • nesting
  • nongame birds
  • patch burn grazing
  • range management
  • reproduction
  • season of fire
  • tallgrass prairie
  • wildlife habitat management
Record Maintained By:
Record Last Modified: June 1, 2018
FRAMES Record Number: 17972
Tall Timbers Record Number: 26337
TTRS Location Status: In-file
TTRS Call Number: Journals - J
TTRS Abstract Status: Okay, Fair use, Reproduced by permission

This bibliographic record was either created or modified by the Tall Timbers Research Station and Land Conservancy and is provided without charge to promote research and education in Fire Ecology. The E.V. Komarek Fire Ecology Database is the intellectual property of the Tall Timbers Research Station and Land Conservancy.


Patch-burn grazing is a management framework designed to promote heterogeneity in grasslands, creating more diverse grassland structure to accommodate the habitat requirements of many grassland species, particularly grassland birds. Published studies on the effects of patch-burn grazing on passerines have been conducted on relatively large (430-980 ha pastures), contiguous grasslands, and only 1 of these studies has investigated the reproductive success of grassland birds. We assessed the effects of the patch-burn grazing and a more traditional treatment on the nesting ecology of grasshopper sparrows (Ammodramus savannarum) in small (<37 ha pastures) grasslands located in southern Iowa from May to August of 2008 and 2009. The study pastures were grazed from May to September and prescribed burns were conducted in the spring. We investigated the effects of treatments on clutch size and modeled grasshopper sparrow nest survival as a function of multiple biological and ecological factors. We found no difference in clutch size between treatments; however, we did find a reduction in clutch size for nests that were parasitized by brown-headed cowbirds {Molothrus ater). Constant daily survival rates were greater in patch-burn grazed pastures than in grazed-and-burned pastures (patch-burn grazed rate (symbol) = 0.930 and grazed-and-burned rate (symbol) = 0.907). Competitive survival models included year, stage of nest, nest age, and cool-season grass (csg) abundance within 5 m of the nest. Overall, csg abundance had the greatest effect on survival and had a negative influence. Although survival rates were highest in patch-burn grazed pastures, multiple factors influenced grasshopper sparrow survival. Nest survival rates for both treatments were relatively low, and variables other than treatment were more instrumental in predicting grasshopper sparrow survival. We recommend decreasing overall vegetation cover if increasing nesting habitat for grasshopper sparrows is a management goal. In addition, we recommend further investigation of heterogeneity management in fragmented landscapes to better understand how it affects biodiversity in relatively small management units that typify grassland habitats in the Midwest.

Online Link(s):
Hovick, Torre J., Miller, James R.; Dinsmore, Stephen J.; Engle, David M.; Debinski, Diane M.; Fuhlendorf, Samuel D. 2012. Effects of fire and grazing on grasshopper sparrow nest survival. Journal of Wildlife Management 76(1):19-27.