Missouri Fish and Wildlife Information System

Navigation

Taxonomy

Common Name: BITTERN, LEAST

Phylum: CHORDATA

Class: AVES

Order: PELECANIFORMES

Family: ARDEIDAE

Genus: IXOBRYCHUS

Species: EXILIS

SubSpecies: EXILIS

Taxonomic Authority: (GMELIN)

Taxonomy References: 003 , 043

Status

NONGAME
STATE RANK S3
GLOBAL RANK G5

Status References: 036 , 028 , 017

Habitat Summary

"Occur in wetlands dominated by dense emergent vegetation and interspersed with open water. Marshes should be greater than 20 acres, and large wetland complexes are preferred. Stable summer water levels are required."

Primary Habitat: "Wetland - marsh"

References: 013 , 014 , 015 , 016

Distribution

General Occurrence in State:

"Uncommon summer resident (local) *01*. Nests mostly in north Missouri *02*."

County Occurance

County Occurence
Known	Likely	Unknown
ADAIR	ANDREW	BARRY
BOLLINGER	ATCHISON	BARTON
BOONE	AUDRAIN	BATES
BUCHANAN	DAVIESS	BENTON
BUTLER	DEKALB	CAMDEN
CALLAWAY	GENTRY	CARTER
CAPE GIRARDEAU	GRUNDY	CASS
CARROLL	HOWARD	CEDAR
CHARITON	KNOX	CHRISTIAN
CLARK	LINN	COLE
CLAY	LIVINGSTON	COOPER
CLINTON	MARION	CRAWFORD
HARRISON	MERCER	DADE
HOLT	MONROE	DALLAS
JACKSON	NODAWAY	DENT
LEWIS	PUTNAM	DOUGLAS
LINCOLN	RALLS	DUNKLIN
MACON	RANDOLPH	FRANKLIN
MONTGOMERY	RAY	GASCONADE
PERRY	SCOTLAND	GREENE
PIKE	SHELBY	HENRY
PLATTE	SULLIVAN	HICKORY
SCHUYLER	WARREN	HOWELL
SCOTT	WORTH	IRON
ST. CHARLES		JASPER
ST. LOUIS		JEFFERSON
STODDARD		JOHNSON
WAYNE		LACLEDE
		LAFAYETTE
		LAWRENCE
		MADISON
		MARIES
		MCDONALD
		MILLER
		MISSISSIPPI
		MONITEAU
		MORGAN
		NEW MADRID
		NEWTON
		OREGON
		OSAGE
		OZARK
		PEMISCOT
		PETTIS
		PHELPS
		POLK
		PULASKI
		REYNOLDS
		RIPLEY
		SALINE
		SHANNON
		ST. CLAIR
		ST. FRANCOIS
		STE. GENEVIEVE
		STONE
		TANEY
		TEXAS
		VERNON
		WASHINGTON
		WEBSTER
		WRIGHT

References for distribution: 027 , 034 , 001 , 002 , 004 , 005 , 006 , 008 , 009 , 010 , 011 , 007 , 012

Distribution by Watersheds

Des Moines R.
Wyaconda R.
North Fabius R. and Middle Fabius R.
South Fabius R.
Miss. R. from Des Moines R. to MO. R.; and North R.
North Fork from Headwaters to South Fork
South Fork from Headwaters to North Fork
Salt R.
Cuivre R.
Dardenne Creek
Miss. R. from St. Louis to River Aux Vases
Meramec R.
Miss. R. from River Aux Vases to Ohio R.
Castor R. and Castor R. Diversion Channel
St. John's Ditch and Blue Ditch
St. Francis R. from Headwaters to Wappapello Dam
St. Francis R. from Wappapello Dam to Arkansas Border
Little R.
Area Bordered by Black R. and St. Francis R. South of Quintan, MO
Mo. R. from Nishnabotna R. to Nodaway R.
Nodaway R.
Mo.R. from Nodaway to Kansas City
Platte R.
One Hundred and Two R.
Grand R. from Headwaters to Shoal Creek
Grand R. from Shoal Creek to MO. R.
Chariton R. from Headwaters to Shuteye Creek
Chariton R. from Shuteye Creek to Mo. R.
Little Chariton R.
South Grand R.
Mo. R. from Kansas City to Little Chariton R.
Mo. R. from Little Chariton R. to Gasconade R.
Mo. R. from Gasconade R. to Miss. R.
Black R.
Current R.

Comments: "Likely to occur in units listed, based on county occurrence."

Distribution by Ecoregions

Central Till Plains, Mississippi River Alluvial Plains, Ozark Highlands

Comments: ""

Distribution by Potential Natural Vegetation

Bluestem Prairie/Oak Hickory Forest
Oak-Hickory Forest
Oak-Hickory-Pine Forest
Southern Floodplain Forest

Distribution by Natural Divisions of Missouri

Glaciated Plains
Glaciated Plains: Western
Glaciated Plains: Grand River
Glaciated Plains: Eastern
Glaciated Plains: Lincoln Hills
Big Rivers
Big Rivers: Upper Missouri
Big Rivers: Lower Missouri
Big Rivers: Upper Mississippi
Big Rivers: Lower Mississippi
Ozark Border
Ozark Border: Missouri River
Ozark Border: Mississippi River
Ozark: St. Francois Mountains
Mississippi Lowlands
Mississippi Lowlands: Crowley's Ridge
Mississippi Lowlands: Lowlands

Habitat Associations

Species is associated with "Terrestrial/Aquatic" habitats.

National Wetlands Inventory Association:

Lacustrine
Palustrine

Aquatic Associations:

"See Comments"
"Lacustrine, littoral", "Emergent"
"Palustrine", "Emergent, persistent",
"Palustrine", "Emergent, persistent",
"Palustrine", "Scrub/shrub, broad-leaved deciduous"

References for Aquatic Associations: 035 , 026 , 031 , 013 , 014 , 015 , 016

Habitat Types:

Pond, Lake, Reservoir
Marsh

References for Habitat Types: 013 , 014 , 015 , 016 , 018

Terrestrial Natural Communities:

Wetland
Marshes
Freshwater Marsh
Pond Marsh
Swamps
Swamp
Pond Swamp
Shrub Swamp
Pond Shrub Swamp

References for Terrestrial Natural Communities: 013 , 014 , 015 , 016

Food Habits

Trophic Level:

"Carnivore"

Larval Food Habits

Comments for larval food habits:
""

References for larval food habits:

Juvenile Food Habits

Osteichthyes (bony fishes); Not Specified
Salientia (frogs, toads, peepers, tree frogs); Not Specified
Malacostraca (lobster, shrimp, crayfish, crabs); Not Specified

Comments for Juvenile Food Habits:
""

References Juvenile Food Habits 013 , 015

Adult Food Habits

Lepidoptera (butterflies); Larva stage
Salientia (frogs, toads, peepers, tree frogs); Larva stage
Hemiptera (water bugs, water boatmen, stink bugs); Not Specified
Diptera (flies, midges, mosquitos, gnats); Not Specified
Osteichthyes (bony fishes); Not Specified
Cypriniformes (minnows, carps, suckers); Not Specified
Perciformes (bass, sunfishes, perches, drums, sculpins); Not Specified
Amphibians; Not Specified
Crustaceans; Not Specified
Malacostraca (lobster, shrimp, crayfish, crabs); Not Specified
Insects Insects; Not Specified
Odonata (dragonflies, damselflies); Not Specified
Orthoptera (grasshoppers, crickets, mantids); Not Specified
Caudata (salamanders, newts, mudpuppies, sirens); Not Specified
Mammals; Not Specified
Aquatic Insects; Not Specified
Terrestrial Insects; Not Specified
Hirudineans (leeches); Not Specified
Snails; Not Specified
Salientia (frogs, toads, peepers, tree frogs); Adult Stage

Comments for Adult Food Habits:
""

References Adult Food Habits 013 , 014 , 015

Niche Requirements

Egg Niche Requirements

References for egg niches requirements:

Feeding Larvae Niche Requirements

References for feeding larvae niche requirements:

Resting Larvae Niche Requirements

References for resting Larvae niche requirements:

Feeding Juvenile Niche Requirements

Aquatic vegetation: cattail (Typha)
Aquatic vegetation: sedge (Carex)
Aquatic vegetation: buttonbush (Cephalanthus)
Aquatic vegetation specified in comments(00120)
Inland wetlands: marsh

References for feeding juvenile niche requirements: 013 , 014 , 015 , 016 , 020

Resting Juvenile Niche Requirements

Aquatic vegetation: cattail (Typha)
Aquatic vegetation: sedge (Carex)
Aquatic vegetation: buttonbush (Cephalanthus)
Aquatic vegetation specified in comments(00120)
Inland wetlands: marsh

References for resting juvenile niche requirements: 013 , 014 , 015 , 016 , 020

Breeding Adult Niche Requirements

Aquatic vegetation: cattail (Typha)
Aquatic vegetation: bulrush (Scirpus)
Aquatic vegetation: sedge (Carex)
Aquatic vegetation: pondweed (Potamogeton)
Aquatic vegetation: smartweed (Polygonum)
Aquatic vegetation: arrowhead (Sagittaria)
Aquatic vegetation: lotus (Nelumbo)
Aquatic vegetation: duckweed (Lemna)
Aquatic vegetation: spike rush (Eleocharis)
Aquatic vegetation: burreed (Sparganium)
Aquatic vegetation: buttonbush (Cephalanthus)
Aquatic vegetation: rushes (Juncus)
Aquatic vegetation specified in comments(00120)
Aquatic vegetation: pickerel weed (Pontederia)
Aquatic vegetation: spatterdock
Open water (%) specified in comments(00135)
Water depth specified in comments(00230)
Inland wetlands: marsh
Distance to open water (in wetland) specified in comments(00435)
Agricultural crops: rice
Agricultural crops specified in comments(00670)

References for feeding Adult niche requirements: 032 , 033 , 040 , 041 , 013 , 014 , 015 , 016 , 020

Feeding Adult Niche Requirements

Aquatic vegetation: cattail (Typha)
Aquatic vegetation: bulrush (Scirpus)
Aquatic vegetation: sedge (Carex)
Aquatic vegetation: buttonbush (Cephalanthus)
Aquatic vegetation specified in comments(00120)
Height of aquatic/emergent vegetation specified in comments(00125)
Density of aquatic vegetation specified in comments(00130)
Floodplain wetlands: remnant wetlands
Floodplain wetlands: unfarmed temporary
Water depth specified in comments(00230)
Inland wetlands: marsh
Inland wetlands: pond, lake, reservoir
Leaf litter/ground debris specified in comments(00460)
Herbaceous cover (%) specified in comments(00620) Herbaceous cover (%) specified in comments

References for feeding adult niche requirements: 037 , 038 , 039 , 042 , 013 , 014 , 015 , 016 , 020

Resting Adult Niche Requirements

References for resting adult niche requirements: 013 , 014 , 015 , 016 , 020

Niche Requirement Summary

Agricultural crops specified in comments(00670)
Agricultural crops: rice
Aquatic vegetation specified in comments(00120)
Aquatic vegetation: arrowhead (Sagittaria)
Aquatic vegetation: bulrush (Scirpus)
Aquatic vegetation: burreed (Sparganium)
Aquatic vegetation: buttonbush (Cephalanthus)
Aquatic vegetation: cattail (Typha)
Aquatic vegetation: duckweed (Lemna)
Aquatic vegetation: lotus (Nelumbo)
Aquatic vegetation: pickerel weed (Pontederia)
Aquatic vegetation: pondweed (Potamogeton)
Aquatic vegetation: rushes (Juncus)
Aquatic vegetation: sedge (Carex)
Aquatic vegetation: smartweed (Polygonum)
Aquatic vegetation: spatterdock
Aquatic vegetation: spike rush (Eleocharis)
Density of aquatic vegetation specified in comments(00130)
Distance to open water (in wetland) specified in comments(00435)
Floodplain specified in comments(00220)
Floodplain wetlands: remnant wetlands
Floodplain wetlands: unfarmed temporary
Height of aquatic/emergent vegetation specified in comments(00125)
Herbaceous cover (%) specified in comments(00620) Herbaceous cover (%) specified in comments
Inland wetlands: marsh
Inland wetlands: pond, lake, reservoir
Leaf litter/ground debris specified in comments(00460)
Open water (%) specified in comments(00135)
Water depth specified in comments(00230)

Comments about Life History:

Code	Comment
015	Nest made of dead vegetation around nest site 13,14,15
026	Male is territorial 14
027	Territory size is unknown 14
003	In SC, were frequently associated with colonies of boat-tailed grackles. Nested both within and outside grackle colonies. Those nesting in grackle colonies had higher nest success than those nesting outside 30
004	Forage by plunging into water 21. May construct feeding platforms of vegetation, that allow chicks and adults to forage without clinging to emergent vegetation; this allows foraging at deeper sites where dense, robust vegetation is lacking 42.
007	In IL, breed may - July, peak egg-laying in June 13. In MO, nested from mid-may to the end of July; in MN, nested June-August 41.
011	Occasionally nest on the ground. Nest may be built on top of old nests of other birds 14,15. A clump of dead vegetation usually forms base of nest 15. Nests in marsh 029.
014	Nest heights vary - 6-24" 15, less than 1 ft. 20, 30-91 cm. 13, 8-14" 14. In MO and MN, nests were built up to 72 cm above the water's surface (average 22-28 cm above water 41.
016	Nest usually 6-8" in diameter 14,15,41, 7-10" 16 nest platform 2-5" thick 14,41
017	Incubation 17-20 days 16, 13.5-19 days 41.
099	Young leave nest before they can fly, when 6-9 days old 13. In MO, 20/37 nests at mingo and 57/126 nests at Squaw Creek fledged young; 13/25 nests in MN fledged young 41. Nest throughout marsh, not just on edge 13. In IL, nests were both solitary and grouped. Grouped nests averaged 26.6 m to nearest neighbor (7.7-38.8 m) 40. In MO and MN, mean distance between nests was 5 and 70 m, respectively 41.
018	Clutch size varies: 1-8 13, 2-6 15,41, 2-5 24 3-6 16 usually 4-5 13,15,16
030	During the breeding season are most active in the evening 13
033	In MO study, spring migration late March to early June, fall migration early August to early November 39. Migration not well known in IL, probably arrive in April and leave between August and October 13.
034	Habitat is a limiting factor 13.

Life History Information

Territoriality specified in comments(026)
Territory size specified in comments(027)
Periodicity specified in comments(030)
Migration patterns specified in comments(033)
Limiting factors specified in comments(034)
Other life history information specified in comments(099)
Origin in state: native
Seasonal distribution in state: spring/summer/fall
Closely associated plant or animal species specified in comments(003)
Foraging strategy: stalking
Foraging strategy specified in comments(004)
Foraging sites: water
Breeding season specified in comments(007)
Mating system: monogamy
Nest/den site: emergent aquatic vegetation
Nest/den site specified in comments(011)
Nest height specified in comments(014)
Nest materials: sticks
Nest materials specified in comments(015)
Nest dimensions specified in comments(016)
Gestation/incubation period specified in comments(017)
Clutch/litter size specified in comments(018)
Number of broods/litter per year: two
Development of young at birth/hatching: altricial
Parental care of young: both parents

Comments about Life History:

Code	Comment
015	Nest made of dead vegetation around nest site 13,14,15
026	Male is territorial 14
027	Territory size is unknown 14
003	In SC, were frequently associated with colonies of boat-tailed grackles. Nested both within and outside grackle colonies. Those nesting in grackle colonies had higher nest success than those nesting outside 30
004	Forage by plunging into water 21. May construct feeding platforms of vegetation, that allow chicks and adults to forage without clinging to emergent vegetation; this allows foraging at deeper sites where dense, robust vegetation is lacking 42.
007	In IL, breed may - July, peak egg-laying in June 13. In MO, nested from mid-may to the end of July; in MN, nested June-August 41.
011	Occasionally nest on the ground. Nest may be built on top of old nests of other birds 14,15. A clump of dead vegetation usually forms base of nest 15. Nests in marsh 029.
014	Nest heights vary - 6-24" 15, less than 1 ft. 20, 30-91 cm. 13, 8-14" 14. In MO and MN, nests were built up to 72 cm above the water's surface (average 22-28 cm above water 41.
016	Nest usually 6-8" in diameter 14,15,41, 7-10" 16 nest platform 2-5" thick 14,41
017	Incubation 17-20 days 16, 13.5-19 days 41.
099	Young leave nest before they can fly, when 6-9 days old 13. In MO, 20/37 nests at mingo and 57/126 nests at Squaw Creek fledged young; 13/25 nests in MN fledged young 41. Nest throughout marsh, not just on edge 13. In IL, nests were both solitary and grouped. Grouped nests averaged 26.6 m to nearest neighbor (7.7-38.8 m) 40. In MO and MN, mean distance between nests was 5 and 70 m, respectively 41.
018	Clutch size varies: 1-8 13, 2-6 15,41, 2-5 24 3-6 16 usually 4-5 13,15,16
030	During the breeding season are most active in the evening 13
033	In MO study, spring migration late March to early June, fall migration early August to early November 39. Migration not well known in IL, probably arrive in April and leave between August and October 13.
034	Habitat is a limiting factor 13.

References for life history: 024 , 029 , 030 , 039 , 040 , 041 , 042 , 001 , 004 , 013 , 014 , 015 , 016 , 020 , 021 , 022 , 023

Management

Beneficial Management Practices:

Water - develop/maintain lakes/ponds
Water - develop/maintain wetlands
Water - develop/maintain freshwater marsh
Water - control sedimentation
Water - control pollution (thermal, physical, chemical)
Water - control water levels
Water - maintain bogs
Water - restrict human disturbance

Beneficial Management References: 025 , 041 , 013 , 014

Adverse Managment Practices:

Water - application of herbicides
Water - application of pesticides
Water - application of insecticides
Water - dredging and filling
Water - control aquatic plants
Water - navigational improvements (channelization, dams, locks)
Water - burning marshes or wetlands
Water - stream channelization
Water - drainage of wetlands, marshes, ponds, lakes

Adverse Management References: 025 , 013 , 014

Comments on Management:
In MO, pools with successful nests had fairly stable water levels throughout the summer *41*.

References for Management Comments: 041

References

Reference Code	Citation
001	Easterla, D.A., M.B. Robbins and R.A. Anderson. 1992. Annotated Check-List Of Missouri Birds. The Audubon Society Of Missouri.
002	Unpb Rather, J. Mo Dept. Of Conservation, 1110 S. College Ave., Columbia, Mo 65201. (573-882-9880).
003	American Ornithologists Union. 1957. Checklist Of North American Birds, 5th Ed. Lord Baltimore Press. Baltimore, Md. 691 Pp.
004	Unpb Wilson, Jim D. Mo Dept. Conserv. P.O. Box 180. Jefferson City, Mo 65102. (573)751-4115.
005	Birds Of Squaw Creek National Wildife Refuge. 1975. U.S. Fish And Wildlife Service. Rf-663560-2.
006	Anderson, R. and P. Bauer. 1968. A Guide To Finding Birds In The St. Louis Area. Webster Groves Nature Study Society. 44 Pp.
007	Kelly, J. and C. Hobbs (Compilers). 1978. Bird Checklist, Greater Kansas City Area. Burroughs Audubon Society Of Kansas City (Publishers).
008	Duck Creek Bird Checklist. 1979. Missouri Dept. Of Conservation, Jefferson City, Mo.
009	Heye, P.L. 1975. A Preliminary List Of The Birds Of The Cape Girardeau, Missouri Area. S.E. Mo State Univ., Cape Girardeau, Mo.
010	Birds Of Mingo National Wildlife Refuge.1970.Department Of The Interior Fish And Wildlife Service.Bureau Of Sport Fisheries And Wildlife.Refuge Leaflet 179-R3.
011	Robbins, M. 1977. Spring Survey. Bluebird 44(2):14-18.
012	Anderson, D. 1974. Spring Survey. Bluebird 41(3):3-5.
013	Graber, J.W., R.R. Graber and E.L. Kirk 1978. Illinois Birds: Ciconiiformes. IL Nat. Hist. Survey Biol. Notes No. 109. 80 Pp.
014	Palmer, R.S. (Ed.) 1962. Handbook Of North American Birds, Vol. 1. Yale Univ. Press. New Haven and London. 567 Pp.
015	Weller, M.W. 1961. Breeding Biology Of The Least Bittern. Wilson Bull. 73:11-35.
016	Harrison, H.H. 1975. A Field Guide To Birds Nests In The United States East Of The Mississippi River. Houghton - Mifflin Co., Boston 257 Pp.
017	The Wildlife Code of Missouri. Missouri Department of Conservation, P.O. Box 180, Jefferson City, MO 65102. 573-751-4115.
018	Kelly, G. (Ed.) 1986. Animal Habitat Relations Handbook. Mo Dept. Of Conservation and U.S.D.A. Forest Service. Jefferson City, Mo. 293 Pp.
019	Thom, R.H. and J.H. Wilson. 1980 The Natural Divisions Of Missouri. Trans. Mo Acad. Sci. 14:9-24.
020	Provost, M.W. 1947. Nesting Birds In The Marshes Of Northwest Iowa. Amer. Midl. Nat. 38:485-503.
021	Kushlan, J.A. 1976. Feeding Behavior Of North American Herons. Auk 93:86-94.
022	Sutton, G.M. 1936. Food-Capturing Tactics Of The Least Bittern. Auk 53:74-75.
023	Eastwood, S.K. 1932. Notes On The Feeding Of The Least Bittern. Wilson Bull. 44:240.
024	Kent, T. 1951. The Least Bitterns Of Swan Lake. Iowa Bird Life 21:59-61.
025	Unpb Fredrickson, L.H. Univ. Of Missouri Gaylord Research Laboratory, Puxico, Mo 63960. (573-222-3203).
026	Unpb Smith, J.W. Mo Dept. Of Conservation, 1110 S. College Ave., Columbia, Mo 65201 (573-882-9880).
027	Unpb Wilson, J.D. and B. Jacobs. 1988. The Distribution And Breeding Status Of The Birds Of Missourii (Preliminary Report). Mo Dept. Of Conservation, P.O. Box 180, Jefferson City, Mo 65102.
028	The Checklist Of Rare And Endangered Species Of Missouri. 1991. Mo Dept. Of Conservation. Jefferson City, Mo. 44 Pp.
029	Smith, J.W. 1987. An Evaluation Of The Effects Of Wetland Management/Greentree Reservoir Management On Birds At The Ted Shanks Wildlife Management Area. Mo Dept. Conserv. P-R Proj. W-13-R-40, Study No. 50, Job No. 2 and 3.
030	Post, W. and C.A. Seals. 1993. Nesting Associations Of Least Bitterns And Boat-Tailed Grackles. Condor 95:139-144.
031	Gates, R.J. and A. Woolf. 1992. Ecology Of Waterfowl In Northeastern Illinois. Il Dept. Of Conservation. Final Report. Project W-102-R(Si). 206 Pp.
032	Hohman, W.L., J.L. Moore, T.M. Stark, G.A. Weisbrich and R.A. Coon. 1994. Breeding Waterbird Use Of Louisiana Rice Fields In Relation To Planting Practices. Proc. Ann. Conf. Southeast Assoc. Fish Wildl. Agencies 48:31-37.
033	Jacobs, K.J., J.P. Dunn, F.E. Hartman and A.J. Nastase. 1993. Effects Of Management Practices Upon Waterfowl Abundance, Usage, And Marsh Ecology In State Game Lands. Pa Game Comm., Final Report For Project 06510, Job 51005. 26 Pp
034	Jacobs, B. and J.D. Wilson. 1997. Missouri Breeding Bird Atlas 1986-1992. Mo Dept. Of Conservation. Natural History Series No. 6. Jefferson City, Mo. 430 Pp.
035	Anderson, J.T., T.C. Tacha, G.T. Muehl and D. Lobpries. 1996. Wetland Use By Waterbirds That Winter In Coastal Texas. Nat. Biol. Serv. Information and Technology Report 8. 40 Pp.
036	Missouri Natural Heritage Program. 2007. Missouri Species and Communities of Conservation Concern Checklist. Missouri Department Of Conservation. Jefferson City, Missouri. 51 Pp.
037	Unpb Ehrhardt, E. 1996. Abundance And Distribution Of Waterbirds On Three Habitats Of Missouri River Floodplain Following A Major Flood. M.S. Thesis, Univ. Of Missouri-Columbia. 126 Pp.
038	Humburg, D.D., K. Bataille, D.L. Helmers and D.A. Brunet. 1999. Wetland Ecology Studies In The Missouri River Floodplain: Evaluation Of Seasonal Habitat Use By Waterbirds On The Missouri River Floodplain Mo Dept. Conserv. Final Rept. Proj. W-13-R-53, Study 18, Job 4. 130 Pp.
039	Unpb Vogel, J. 1999. Migration Chronology And Habitat Use Of Webless Migratory Game Birds In Lower Missouri River Floodplain Wetlands. Ms Thesis, Univ. Of Missouri-Columbia. 92 Pp.
040	Bowyer, M.W., J.W. Walk and T.L. Esker. 2002. Use Of Moist Soil Units At Carlyle Lake Wildlife Management Area By Least Bitterns And Other Threatened Birds During The Breeding Season. Trans. Il State Acad. Sci. 95(2002):59-64.
041	Arnold, K. and F. Nelson. 2002. Nesting Ecology Of Least Bitterns At Agassiz, Mingo And Squaw Creek National Wildlife Refuges. Gaylord Memorial Laboratory Spec. Publ. No. 3. 16 Pp.
042	unpb Reid, F.A. 1989. Differential Habitat Use By Waterbirds In A Managed Wetland Complex. Ph.D. Diss., Univ. Of Missouri-Columbia. 270 Pp.
043	Chesser, R.T., R.C. Banks, F.K. Barker, C.Cicero, J.L. Dunn, A.W. Kratter, I.J. Lovette, P.C. Rasmussen, J.V. Remsen, Jr., J.D. Rising, D.F. Stotz and K.Winker. 2010. 51st Supplement to the American Ornithologists' Union Check-list of North American Birds. Auk 127(3):726-744.