MONITORING GRASSLAND BIRD POPULATIONS ON FORT CAMPBELL MILITARY RESERVATION, KENTUCKY-TENNESSEE, WITH A SPECIAL EMPHASIS ON BACHMAN’S SPARROW (Peucaea aestivalis)

Grassland birds have declined more in the past four decades than any other group, primarily because of the suppression of ecological disturbance. Fort Campbell Military Reservation (FCMR) has maintained large amounts of grasslands and oak (Quercus spp.) savannas because of military training and prescribed fires, and supports many grassland bird populations. I established a survey route to investigate vegetation influencing occupancy of grassland birds with an emphasis on Bachman’s Sparrows (Peucaea aestivalis), and additionally described habitat selection of Bachman’s Sparrows on FCMR. Bachman’s Sparrow, Eastern Meadowlark (Sturnella magna), Henslow’s Sparrow (Ammodramus henslowii), and Orchard Oriole (Icterus spurius) occupancy were positively related to grass cover (β [beta] = 10.02 ± [plus-minus] 2.80 SE, β = 9.93 ± 2.05 SE, β = 7.09 ± 2.35 SE, β = 17.12 ± 5.81 SE), whereas Blue Grosbeak (Passerina caerulea) and Northern Bobwhite (Colinus virginianus) occupancy were related to grass cohesion (β = 0.08 ± 0.03 SE, β = 0.08 ± 0.02 SE). Blue-winged Warbler (Vermivora cyanoptera) occupancy was positively related to shrub cover (β = 4.90 ± 1.85 SE), Prairie Warbler (Setophaga discolor) occupancy was positively related to interspersion and juxtaposition (β = 0.05 ± 0.02 SE), and Dickcissel (Spiza americana) occupancy was negatively related to tree cover (β = -7.28 ± 0.48 SE). Bachman’s Sparrow territory size averaged 2.66 ha (± 0.57 SE); basal area was 2.25 m²/ha [meters squared per hectacre] (± 0.57 SE). Occupied territories had greater cover of forbs than unoccupied savannas (27% ± 1.55 SE vs 22% ± 1.02 SE, p = 0.0001) and greater variance in litter (0.71 ± 0.03 SE vs 0.6 ± 0.02 SE, p = 0.01). There was less variance between occupied and unoccupied territory points for bareground (0.58 ± 0.02 SE vs 0.66 ±0.03 SE, p = 0.02), forbs (0.47 ± 0.01 SE vs 0.53 ± 0.02 SE, p = 0.02), and woody species (0.85 ± 0.03 SE vs 0.96 ± 0.04, p = 0.03). Our goal is to use these data to develop a conservation strategy to monitor and enhance Bachman’s Sparrows and other high-priority species at FCMR and elsewhere in the region.