Camp Gruber

Migratory Bird Survey

Dan recording the results of a count.

Dan recording the results of a count.

Camp Gruber is an Oklahoma Army National Guard training center located near Muskogee, Oklahoma. A wide range of training activities takes place there for National Guardsmen and other military personnel as well as federal, state, and local law enforcement personnel. One task of the Environmental Section at Camp Gruber is to monitor and maintain environmental quality, including the health of wildlife populations and their habitats.

Over 60,000 acres (24,000 ha) of habitat are available at Camp Gruber, much of it undisturbed except for a network of rough, little used, one-lane dirt roads. About half of this total acreage is available for training use and the other half is set aside as a game management area with limited access by the public.

Partial map of Camp Gruber, showing roads, forests (blue), and grasslands(yellow).

Partial map of Camp Gruber, showing roads, forests (blue), and grasslands(yellow).

The Sutton Center was contracted to conduct bird surveys along 100 m transects at 89 randomly selected points distributed between the training portion of the site and the game management area. A comparison can then be made between species diversity on the training site and that off the training site in a largely undisturbed adjacent area. Occurrence of less common species can also be evaluated to determine any preference for one or the other areas.

The surveys took place in May and June, 1998, and again in 1999. On the 89 counts surveyed in 1998, we recorded 93 bird species and approximately 2,750 individuals, including year-round residents and wintering, transient, and breeding migrants. In 1999, we recorded 81 species and 3,289 individuals.


Survey Results

cgplotsThe survey of Neotropical migrant and other species of birds was carried out at Camp Gruber Training Center, Cherokee Public Hunting Area, and Cherokee Game Management Area, on 4 May to 5 June 1998, and again in 1999.The survey was made at 89 Land Condition Trend Analysis (LCTA) plots, red dots on map at left, each of which was visited twice (once in the morning and once in the evening). The observers counted all birds following the LCTA count methodology.

On this and the following maps, the green color indicates forested habitat, and the dark yellow indicates open habitat (grassland, urban / cantonment, and open woodland).



A total of 2750 individual birds of 93 species was recorded on the counts in 1998, with an additional ten species recorded at Camp Gruber, but not during the counts. The median number of species per plot was 15, with a range from six to 25. The average number of individual birds per plot was 30.9, with a range from ten to 75, but between 22 and 37 individuals were recorded on most plots.




Bird species were divided into five migratory status categories. The numbers of individuals in the wintering and transient categories were low. Of the three categories in which individuals also breed at Camp Gruber, the most frequently detected were resident species, followed by short-distance and then by long-distance migrants.

cghabitThe bird species were also divided by placing them in five habitat-use categories. The greatest number of individuals was recorded in the forest habitat, with the second greatest number in edge habitats, where forest and open habitats come together. Fewer birds were recorded in the aerial (swallows and swifts), aquatic (herons, ducks, and so forth), and grassland categories.





cgdickcWe present here a pair of maps of species showing their contrasting patterns of distribution at Camp Gruber. Dickcissels occurred only in the open habitat, specifically in the grassland.






cgreviRed-eyed Vireos, in contrast, were never found in the open habitat, but only in the forested habitats.Some other species, such as Yellow-billed Cuckoo and Indigo Bunting, were found about as often in the open habitat as in the forest.





Camp Gruber serves as a stopover site for Neotropical migrant birds, but transient migrants composed only about 3.3 % of the total number of birds recorded during the survey. This number may belie the actual importance of Camp Gruber to transients, because transients are less likely to be detected than species breeding in the area.

The habitat diversity at Camp Gruber seems to be generally good, providing large areas of moderately-mature forest, small open patches within that forest, open woodland, much edge, grassland, urban areas in the cantonment, plus marshes, ponds, wetlands, streamsides, and aquatic habitat. This diverse mosaic of habitats provides breeding and foraging areas for many species of birds. Although the entire area probably should not be allowed to return to mature, tall trees, the current trend toward maturing of the forest should be allowed to continue over some fairly large areas.

No threatened or endangered species were recorded at Camp Gruber during this survey. Two birds, the threatened Piping Plover and the endangered subspecies Interior Least Tern, may occur in migration on the Arkansas River that forms the northwestern boundary of Camp Gruber. Possibly the most unique and rare species encountered at Camp Gruber during this survey was Henslow’s Sparrow.

Species Observed

The following table is a list of all 103 species recorded during the counts in 1998 and 1999 at Camp Gruber.

Species Scientific Name Family
Great Egret Ardea alba Ardeidae
Cattle Egret Bubulcus ibis Ardeidae
Little Blue Heron Egretta caerulea Ardeidae
Black Vulture Coragyps atratus Cathartidae
Turkey Vulture Cathartes aura Cathartidae
Northern Harrier Circus cyaneus Accipitridae
Cooper’s Hawk Accipiter cooperii Accipitridae
Red-shouldered Hawk Buteo lineatus Accipitridae
Broad-winged Hawk Buteo platypterus Accipitridae
Red-tailed Hawk Buteo jamaicensis Accipitridae
Wild Turkey Meleagris gallopavo Phasianidae
Northern Bobwhite Colinus virginianus Odontophoridae
Killdeer Charadrius vociferus Charadriidae
Rock Dove Columba livia Columbidae
Mourning Dove Zenaida macroura Columbidae
Yellow-billed Cuckoo Coccyzus americanus Cuculidae
Eastern Screech-Owl Otus asio Strigidae
Great Horned Owl Bubo virginianus Strigidae
Barred Owl Strix varia Strigidae
Common Nighthawk Chordeiles minor Caprimulgidae
Chuck-will’s-widow Caprimulgus carolinensis Caprimulgidae
Chimney Swift Chaetura pelagica Apodidae
Ruby-throated Hummingbird Archilochus colubris Trochilidae
Red-headed Woodpecker Melanerpes erythrocephalus Picidae
Red-bellied Woodpecker Melanerpes carolinus Picidae
Downy Woodpecker Picoides pubescens Picidae
Hairy Woodpecker Picoides villosus Picidae
Northern Flicker Colaptes auratus Picidae
Pileated Woodpecker Dryocopus pileatus Picidae
Olive-sided Flycatcher Contopus cooperi Tyrannidae
Eastern Wood-Pewee Contopus virens Tyrannidae
Acadian Flycatcher Empidonax virescens Tyrannidae
Least Flycatcher Empidonax minimus Tyrannidae
Unidentified Empidonax Empidonax sp. Tyrannidae
Eastern Phoebe Sayornis phoebe Tyrannidae
Great Crested Flycatcher Myiarchus crinitus Tyrannidae
Eastern Kingbird Tyrannus tyrannus Tyrannidae
Scissor-tailed Flycatcher Tyrannus forficatus Tyrannidae
White-eyed Vireo Vireo griseus Vireonidae
Bell’s Vireo Vireo bellii Vireonidae
Yellow-throated Vireo Vireo flavifrons Vireonidae
Blue-headed Vireo Vireo solitarius Vireonidae
Warbling Vireo Vireo gilvus Vireonidae
Red-eyed Vireo Vireo olivaceus Vireonidae
Blue Jay Cyanocitta cristata Corvidae
American Crow Corvus brachyrhynchos Corvidae
Fish Crow Corvus ossifragus Corvidae
Purple Martin Progne subis Hirundinidae
Northern Rough-winged Swallow Stelgidopteryx serripennis Hirundinidae
Barn Swallow Hirundo rustica Hirundinidae
Carolina Chickadee Poecile carolinensis Paridae
Tufted Titmouse Baeolophus bicolor Paridae
White-breasted Nuthatch Sitta carolinensis Sittidae
Carolina Wren Thryothorus ludovicianus Troglodytidae
Marsh Wren Cistothorus palustris Troglodytidae
Sedge Wren Cistothorus platensis Troglodytidae
Blue-gray Gnatcatcher Polioptila caerulea Sylviidae
Eastern Bluebird Sialia sialis Turdidae
Gray-cheeked Thrush Catharus minimus Turdidae
Swainson’s Thrush Catharus ustulatus Turdidae
Wood Thrush Hylocichla mustelina Turdidae
Gray Catbird Dumetella carolinensis Mimidae
Northern Mockingbird Mimus polyglottos Mimidae
Brown Thrasher Toxostoma rufum Mimidae
European Starling Sturnus vulgaris Sturnidae
Cedar Waxwing Bombycilla cedrorum Bombycillidae
Tennessee Warbler Vermivora peregrina Parulidae
Nashville Warbler Vermivora ruficapilla Parulidae
Northern Parula Parula americana Parulidae
Yellow Warbler Dendroica petechia Parulidae
Yellow-rumped Warbler Dendroica coronata Parulidae
Yellow-throated Warbler Dendroica dominica Parulidae
Prairie Warbler Dendroica discolor Parulidae
Black-and-white Warbler Mniotilta varia Parulidae
American Redstart Setophaga ruticilla Parulidae
Prothonotary Warbler Protonotaria citrea Parulidae
Ovenbird Seiurus aurocapillus Parulidae
Louisiana Waterthrush Seiurus motacilla Parulidae
Kentucky Warbler Oporornis formosus Parulidae
Common Yellowthroat Geothlypis trichas Parulidae
Yellow-breasted Chat Icteria virens Parulidae
Summer Tanager Piranga rubra Thraupidae
Field Sparrow Spizella pusilla Emberizidae
Savannah Sparrow Passerculus sandwichensis Emberizidae
Grasshopper Sparrow Ammodramus savannarum Emberizidae
Henslow’s Sparrow Ammodramus henslowii Emberizidae
Lincoln’s Sparrow Melospiza lincolnii Emberizidae
Chipping Sparrow Spizella passerina Emberizidae
Lark Sparrow Chondestes grammacus Emberizidae
White-crowned Sparrow Zonotrichia leucophrys Emberizidae
Northern Cardinal Cardinalis cardinalis Cardinalidae
Rose-breasted Grosbeak Pheucticus ludovicianus Cardinalidae
Blue Grosbeak Guiraca caerulea Cardinalidae
Indigo Bunting Passerina cyanea Cardinalidae
Painted Bunting Passerina ciris Cardinalidae
Dickcissel Spiza americana Cardinalidae
Red-winged Blackbird Agelaius phoeniceus Icteridae
Eastern Meadowlark Sturnella magna Icteridae
Common Grackle Quiscalus quiscula Icteridae
Brown-headed Cowbird Molothrus ater Icteridae
Orchard Oriole Icterus spurius Icteridae
Baltimore Oriole Icterus galbula Icteridae
American Goldfinch Carduelis tristis Fringillidae


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