Egretta caerulea - (Linnaeus, 1758)
Little Blue Heron
Other English Common Names: little blue heron
Other Common Names: Garça-Azul
Synonym(s): Florida caerulea
Taxonomic Status: Accepted
Related ITIS Name(s): Egretta caerulea (Linnaeus, 1758) (TSN 174827)
French Common Names: Aigrette bleue
Spanish Common Names: Garceta Azul, Garza Azul
Unique Identifier: ELEMENT_GLOBAL.2.106018
Element Code: ABNGA06040
Informal Taxonomy: Animals, Vertebrates - Birds - Wading Birds
Image 11066

© Jeff Nadler

 
Kingdom Phylum Class Order Family Genus
Animalia Craniata Aves Pelecaniformes Ardeidae Egretta
Genus Size: C - Small genus (6-20 species)
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Concept Reference
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Concept Reference: American Ornithologists' Union (AOU). 1998. Check-list of North American birds. Seventh edition. American Ornithologists' Union, Washington, D.C. [as modified by subsequent supplements and corrections published in The Auk]. Also available online: http://www.aou.org/.
Concept Reference Code: B98AOU01NAUS
Name Used in Concept Reference: Egretta caerulea
Taxonomic Comments: Often placed in monotypic genus florida (AOU 1983).
Conservation Status
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NatureServe Status

Global Status: G5
Global Status Last Reviewed: 07Apr2016
Global Status Last Changed: 20Nov1996
Ranking Methodology Used: Ranked by inspection
Rounded Global Status: G5 - Secure
Reasons: Very large range. Globally secure, but regional trends are unknown for most areas.
Nation: United States
National Status: N5B,N5N (05Jan1997)

U.S. & Canada State/Province Status
Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
United States Alabama (S3N,S4B), Arizona (S1S2N), Arkansas (S2B), California (SNR), Colorado (SNA), Connecticut (S1B), Delaware (S1B), District of Columbia (S3N), Florida (S4), Georgia (S4), Illinois (S1), Indiana (SNA), Iowa (S2N), Kansas (S3B), Kentucky (S1B), Louisiana (S3N,S5B), Maine (S1B), Maryland (S3B), Massachusetts (S1B,S3N), Michigan (SNRN), Minnesota (SNA), Mississippi (S2B), Missouri (S3), Nebraska (SNRN), New Hampshire (SNA), New Jersey (S3B,S3N), New Mexico (S1B,S4N), New York (S2), North Carolina (S3B,S3N), Ohio (S1), Oklahoma (S5B), Pennsylvania (SNA), Rhode Island (S1B,S2N), South Carolina (SNRB,SNRN), South Dakota (S2B), Tennessee (S2B,S3N), Texas (S5B), Virginia (S2B,S3N), West Virginia (SNA)

Other Statuses

IUCN Red List Category: LC - Least concern

NatureServe Global Conservation Status Factors

Range Extent: >2,500,000 square km (greater than 1,000,000 square miles)
Range Extent Comments: BREEDS: southern California (casually, since 1979), southern Sonora, southeastern New Mexico, northern Texas, central Oklahoma, central Kansas, southwestern Kentucky, southern Georgia, and Atlantic coast north to Maine, south along both coasts of Mexico and Middle America, to the West Indies and South America (Colombia, Venezuela, and Guianas west of Andes to central Peru and east of Andes to eastern Peru, central Brazil, and Uruguay; sometimes in central Minnesota. See Spendelow and Patton (1988) for information on distribution and abundance of coastal U.S. breeding populations. NORTHERN WINTER: north to southern Baja California, southern Sonora, Gulf Coast, and Virginia, south through most of the breeding range. In the U.S., the highest winter densities occur in southern Louisiana bayous, around the mouth of the Mississippi River, especially the Delta NWR, and to a much lesser extent in Florida (Root 1988). Wanders irregularly outside usual range, especially after breeding. Accidental or casual in Hawaii.

Overall Threat Impact Comments: Vulnerable to disturbance and development of nesting and foraging areas; natural weather phenomena and shoreline dynamics sometimes have adverse effects (Byrd and Johnston 1991).

Other NatureServe Conservation Status Information

Distribution
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Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) BREEDS: southern California (casually, since 1979), southern Sonora, southeastern New Mexico, northern Texas, central Oklahoma, central Kansas, southwestern Kentucky, southern Georgia, and Atlantic coast north to Maine, south along both coasts of Mexico and Middle America, to the West Indies and South America (Colombia, Venezuela, and Guianas west of Andes to central Peru and east of Andes to eastern Peru, central Brazil, and Uruguay; sometimes in central Minnesota. See Spendelow and Patton (1988) for information on distribution and abundance of coastal U.S. breeding populations. NORTHERN WINTER: north to southern Baja California, southern Sonora, Gulf Coast, and Virginia, south through most of the breeding range. In the U.S., the highest winter densities occur in southern Louisiana bayous, around the mouth of the Mississippi River, especially the Delta NWR, and to a much lesser extent in Florida (Root 1988). Wanders irregularly outside usual range, especially after breeding. Accidental or casual in Hawaii.

U.S. States and Canadian Provinces

Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
Color legend for Distribution Map
NOTE: The maps for birds represent the breeding status by state and province. In some jurisdictions, the subnational statuses for common species have not been assessed and the status is shown as not-assessed (SNR). In some jurisdictions, the subnational status refers to the status as a non-breeder; these errors will be corrected in future versions of these maps. A species is not shown in a jurisdiction if it is not known to breed in the jurisdiction or if it occurs only accidentally or casually in the jurisdiction. Thus, the species may occur in a jurisdiction as a seasonal non-breeding resident or as a migratory transient but this will not be indicated on these maps. See other maps on this web site that depict the Western Hemisphere ranges of these species at all seasons of the year.
Endemism: occurs (regularly, as a native taxon) in multiple nations

U.S. & Canada State/Province Distribution
United States AL, AR, AZ, CA, CO, CT, DC, DE, FL, GA, IA, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS, NC, NE, NH, NJ, NM, NY, OH, OK, PA, RI, SC, SD, TN, TX, VA, WV

Range Map
Note: Range depicted for New World only. The scale of the maps may cause narrow coastal ranges or ranges on small islands not to appear. Not all vagrant or small disjunct occurrences are depicted. For migratory birds, some individuals occur outside of the passage migrant range depicted. For information on how to obtain shapefiles of species ranges see our Species Mapping pages at www.natureserve.org/conservation-tools/data-maps-tools.

Range Map Compilers: NatureServe, 2002


U.S. Distribution by County Help
State County Name (FIPS Code)
CT Fairfield (09001), Middlesex (09007), New Haven (09009), New London (09011)
DE New Castle (10003), Sussex (10005)
FL Alachua (12001), Baker (12003), Bay (12005), Bradford (12007), Brevard (12009), Broward (12011), Calhoun (12013), Charlotte (12015), Citrus (12017), Clay (12019), Collier (12021), Columbia (12023), DeSoto (12027), Dixie (12029), Duval (12031), Escambia (12033), Franklin (12037), Gadsden (12039), Gilchrist (12041), Glades (12043), Gulf (12045), Hamilton (12047), Hardee (12049), Hendry (12051), Hernando (12053), Highlands (12055), Hillsborough (12057), Holmes (12059), Indian River (12061), Jackson (12063), Jefferson (12065), Lafayette (12067), Lake (12069), Lee (12071), Leon (12073), Levy (12075), Madison (12079), Manatee (12081), Marion (12083), Martin (12085), Miami-Dade (12086), Monroe (12087), Nassau (12089), Okeechobee (12093), Orange (12095), Osceola (12097), Palm Beach (12099), Pasco (12101), Pinellas (12103), Polk (12105), Putnam (12107), Sarasota (12115), St. Johns (12109), St. Lucie (12111), Sumter (12119), Suwannee (12121), Taylor (12123), Volusia (12127), Wakulla (12129), Walton (12131), Washington (12133)
ID Minidoka (16067)
IL Alexander (17003), Cook (17031)*, DuPage (17043)*, Franklin (17055)*, Madison (17119), St. Clair (17163)
KS Barton (20009), Cherokee (20021), Linn (20107), Reno (20155), Sedgwick (20173), Stafford (20185)
KY Jefferson (21111)*, Lyon (21143), Trigg (21221)*
MD Somerset (24039), Talbot (24041), Worcester (24047)
MO Jackson (29095), Mississippi (29133), Pemiscot (29155), Pike (29163), Scott (29201), Vernon (29217)
MS Claiborne (28021), Coahoma (28027), George (28039), Hinds (28049), Holmes (28051), Issaquena (28055), Jackson (28059), Lawrence (28077), Madison (28089), Marion (28091), Newton (28101), Rankin (28121), Sharkey (28125), Tallahatchie (28135), Warren (28149), Washington (28151), Yazoo (28163)
NC Brunswick (37019), Carteret (37031), Columbus (37047), Cumberland (37051), Currituck (37053), Dare (37055), Hyde (37095), Jones (37103), New Hanover (37129), Pender (37141), Robeson (37155)
NJ Atlantic (34001), Bergen (34003), Cape May (34009), Hudson (34017), Middlesex (34023), Monmouth (34025), Ocean (34029)
NM Eddy (35015)*
NY Bronx (36005), Kings (36047), Nassau (36059), Richmond (36085), Suffolk (36103)
RI Newport (44005)
SC Barnwell (45011)*, Berkeley (45015)
SD Brown (46013), Charles Mix (46023)*, Codington (46029), Kingsbury (46077)
TN Benton (47005), Dyer (47045), Hardin (47071), Houston (47083), Lauderdale (47097)
VA Accomack (51001), Northampton (51131)
* Extirpated/possibly extirpated
U.S. Distribution by Watershed Help
Watershed Region Help Watershed Name (Watershed Code)
01 Narragansett (01090004)+
02 Bronx (02030102)+, Hackensack-Passaic (02030103)+, Sandy Hook-Staten Island (02030104)+, Raritan (02030105)+, Southern Long Island (02030202)+, Long Island Sound (02030203)+, Delaware Bay (02040204)+, Mullica-Toms (02040301)+, Great Egg Harbor (02040302)+, Chincoteague (02040303)+, Eastern Lower Delmarva (02040304)+, Upper Chesapeake Bay (02060001)+, Chester-Sassafras (02060002)+, Choptank (02060005)+, Lower Chesapeake Bay (02080101)+, Western Lower Delmarva (02080109)+, Eastern Lower Delmarva (02080110)+, Pokomoke-Western Lower Delmarva (02080111)+
03 Albemarle (03010205)+, Pamlico Sound (03020105)+, Lower Neuse (03020204)+, White Oak River (03020301)+, Lower Cape Fear (03030005)+, Black (03030006)+, Lumber (03040203)+, Waccamaw (03040206)+, Cooper (03050201)+, Middle Savannah (03060106)+*, St. Marys (03070204)+, Nassau (03070205)+, Upper St. Johns (03080101)+, Oklawaha (03080102)+, Lower St. Johns (03080103)+, Daytona - St. Augustine (03080201)+, Cape Canaveral (03080202)+, Vero Beach (03080203)+, Kissimmee (03090101)+, Western Okeechobee Inflow (03090103)+, Lake Okeechobee (03090201)+, Everglades (03090202)+, Florida Bay-Florida Keys (03090203)+, Big Cypress Swamp (03090204)+, Caloosahatchee (03090205)+, Florida Southeast Coast (03090206)+, Peace (03100101)+, Myakka (03100102)+, Charlotte Harbor (03100103)+, Sarasota Bay (03100201)+, Manatee (03100202)+, Alafia (03100204)+, Hillsborough (03100205)+, Tampa Bay (03100206)+, Crystal-Pithlachascotee (03100207)+, Withlacoochee (03100208)+, Waccasassa (03110101)+, Econfina-Steinhatchee (03110102)+, Aucilla (03110103)+, Upper Suwannee (03110201)+, Alapaha (03110202)+, withlacoochee (03110203)+, Lower Suwannee (03110205)+, Santa Fe (03110206)+, Apalachee Bay-St. Marks (03120001)+, Lower Ochlockonee (03120003)+, Lower Chattahoochee (03130004)+, Apalachicola (03130011)+, Chipola (03130012)+, New (03130013)+, Apalachicola Bay (03130014)+, St. Andrew-St. Joseph Bays (03140101)+, Yellow (03140103)+, Perdido Bay (03140107)+, Pea (03140202)+, Lower Choctawhatchee (03140203)+, Chunky-Okatibbee (03170001)+, Pascagoula (03170006)+, Mississippi Coastal (03170009)+, Middle Pearl-Strong (03180002)+, Middle Pearl-Silver (03180003)+, Lower Pearl. Mississippi (03180004)+
04 Little Calumet-Galien (04040001)+*
05 Lower Cumberland (05130205)+, Silver-Little Kentucky (05140101)+*
06 Lower Tennessee-Beech (06040001)+, Kentucky Lake (06040005)+
07 The Sny (07110004)+, Salt (07110007)+, Chicago (07120003)+*, Des Plaines (07120004)+*, Cahokia-Joachim (07140101)+, Upper Mississippi-Cape Girardeau (07140105)+, Big Muddy (07140106)+*
08 Lower Mississippi-Memphis (08010100)+, Obion (08010202)+, North Fork Forked Deer (08010204)+*, Lower Hatchie (08010208)+*, Lower Mississippi-Helena (08020100)+, New Madrid-St. Johns (08020201)+, Little River Ditches (08020204)+, Tallahatchie (08030202)+, Upper Yazoo (08030206)+, Big Sunflower (08030207)+, Lower Yazoo (08030208)+, Deer-Steele (08030209)+, Upper Big Black (08060201)+, Bayou Pierre (08060203)+
10 Fort Randall Reservoir (10140101)+*, Upper James (10160003)+, Lewis and Clark Lake (10170101)+*, South Big Sioux Coteau (10170103)+, Middle Big Sioux Coteau (10170201)+, Upper Big Sioux (10170202)+*, Lower Marais Des Cygnes (10290102)+, Little Osage (10290103)+, Lower Missouri-Crooked (10300101)+
11 Rattlesnake (11030009)+, Gar-Peace (11030010)+, Cow (11030011)+, Middle Arkansas-Slate (11030013)+, Spring (11070207)+
13 Upper Pecos-Black (13060011)+*
17 Lake Walcott (17040209)+
+ Natural heritage record(s) exist for this watershed
* Extirpated/possibly extirpated
Ecology & Life History
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General Description: See Kaufman (1991, Am. Birds 45:330-333) for detailed information on identification.
Reproduction Comments: Clutch size is 3-6 (usually 4-5) in north, 2-4 in Central America. Incubation lasts 22-24 days, by both sexes. Young are tended by both parents, can leave nest by 12 days, fledge within 4 weeks.
Ecology Comments: Usually alone or in scattered 2s or 3s (Hilty and Brown 1986). Forages singly, congregates to roost or loaf (Stiles and Skutch 1989).
Non-Migrant: Y
Locally Migrant: Y
Long Distance Migrant: Y
Mobility and Migration Comments: Northern populations are migratory. Individuals banded in North America have been recorded in Colombia November-March (Hilty and Brown 1986).
Estuarine Habitat(s): Herbaceous wetland, Lagoon, Scrub-shrub wetland, Tidal flat/shore
Riverine Habitat(s): Low gradient
Lacustrine Habitat(s): Shallow water
Palustrine Habitat(s): FORESTED WETLAND, HERBACEOUS WETLAND, Riparian, SCRUB-SHRUB WETLAND
Habitat Comments: Marshes, ponds, lakes, meadows, mudflats, lagoons, streams, mangrove lagoons, and other bodies of calm shallow water; primarily in freshwater habitats.

Nests in trees and shrubs to about 4 m above ground or water, primarily in freshwater situations; usually in mangroves in the tropics. Often nests with other herons, egrets, and/or ibises.

Adult Food Habits: Carnivore, Invertivore, Piscivore
Immature Food Habits: Carnivore, Invertivore, Piscivore
Food Comments: Eats various small aquatic animals, also grassland insects, especially when marshes and swamps dry; generally forages ashore or in mud or shallow water, seldom feeds in salt water (Palmer 1962).
Adult Phenology: Crepuscular, Diurnal
Immature Phenology: Crepuscular, Diurnal
Phenology Comments: Forages during daylight (Powell 1987).
Colonial Breeder: Y
Length: 61 centimeters
Weight: 364 grams
Economic Attributes Not yet assessed
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Management Summary Not yet assessed
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Population/Occurrence Delineation
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Group Name: Colonial Wading Birds

Use Class: Breeding
Subtype(s): Foraging Area, Breeding Colony
Minimum Criteria for an Occurrence: Evidence of historical breeding , or current and likely recurring breeding, at a given location, minimally a reliable observation of one or more breeding pairs in appropriate habitat. Small heron colonies (rookeries or heronries) are often ephemeral in nature; recommend tracking rookeries which maintain a minimum of 15 active nests over 2-3 years. Where concentrations of non-breeding individuals occur within the boundaries of a breeding occurrence (especially if augmented by migrants), consider creating a separate occurrence with Location Use Class 'Nonbreeding.'
Mapping Guidance: Map Foraging Areas in separate polygons from the breeding colony if they are separated from the colony by areas simply flown over on commuting routes.
Separation Barriers: None.
Separation Distance for Unsuitable Habitat: 5 km
Separation Distance for Suitable Habitat: 10 km
Separation Justification: Occurrences include breeding colonies and foraging areas, but the separation distance pertains to breediing colonies. Hence, difference occurrences may overlap. Unsuitable habitat: upland areas, except those known to be used regularly for foraging (e.g., meadows used by great egrets).

Separation distance is an arbitrary compromise between the high mobility of these birds and the need for occurrences of practical size for conservation planning. Occurrences do not necessarily represent discrete populations or metapopulations.

Colony fidelity low in some species (e.g. Roseate Spoonbill, Dumas 2000; Glossy Ibis, Davis and Kricher 2000).

Feeding areas associated with a breeding colony (i.e. different features of the same occurrence) may be a number of kilometers away from the colony: averaging 12 kilometers for Roseate Spoonbill (Dumas 2000); 7.3 kilometers for Glossy Ibis (Davis and Kricher 2000); 2.8 to more than 5 kilometers for Snowy Egrets (Smith 1995).

Inferred Minimum Extent of Habitat Use (when actual extent is unknown): 3 km
Inferred Minimum Extent Justification: A low mean foraging range size for this group.
Date: 28Oct2004
Author: Cannings, S., and G. Hammerson

Use Class: Nonbreeding
Subtype(s): Roost, Foraging area
Minimum Criteria for an Occurrence: Evidence of recurring presence of flocks of non-breeding birds (including historical), including non-breeding birds within the breeding season and breeding individuals outside the breeding season; and potential recurring presence at a given location. Normally only areas where concentrations greater than 10 birds occur regularly for at least 20 days per year would be deemed occurrences. Be cautious about creating occurrences for observations that may represent single events.
Separation Barriers: None.
Separation Distance for Unsuitable Habitat: 10 km
Separation Distance for Suitable Habitat: 10 km
Separation Justification: Separation distance arbitrary, set at 10 kilometers to define occurrences of manageable size for conservation purposes. Occurrences defined primarily on the basis of areas supporting concentrations of foraging birds, rather than on the basis of distinct populations.
Inferred Minimum Extent of Habitat Use (when actual extent is unknown): 3 km
Inferred Minimum Extent Justification: Based on foraging ranges from breeding rookeries.
Date: 19Apr2002
Author: Cannings, S.
Population/Occurrence Viability
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U.S. Invasive Species Impact Rank (I-Rank) Not yet assessed
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Authors/Contributors
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NatureServe Conservation Status Factors Edition Date: 22Dec1994
Element Ecology & Life History Edition Date: 22Dec1994
Element Ecology & Life History Author(s): HAMMERSON, G.

Zoological data developed by NatureServe and its network of natural heritage programs (see Local Programs) and other contributors and cooperators (see Sources).

References
Help
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  • Sauer, J.R., J.E. Hines, and J. Fallon. 2007. The North American breeding bird survey, results and analysis 1966-2006. Version 10.13.2007. US Geological Survey, Patuxent Wildlife Research Center, Laurel, MD.

  • See SERO listing

  • Sibley, D. A. 2000a. The Sibley guide to birds. Alfred A. Knopf, New York.

  • Smith, J. P. 1995. Foraging flights and habitat use of nesting wading birds (Ciconiiformes) at Lake Okeechobee, Florida. Colonial Waterbirds 18:139-158.

  • Spendelow, J. A. and S. R. Patton. 1988. National Atlas of Coastal Waterbird Colonies in the Contiguous United States: 1976-1982. U.S. Fish and Wildlife Service, Biological Report 88(5). x + 326 pp.

  • Stiles, F. G. and A. F. Skutch. 1989. A guide to the birds of Costa Rica. Cornell University Press, Ithaca, New York, USA. 511 pp.

  • Stokes, D. W., and L. Q. Stokes. 1996. Stokes field guide to birds: western region. Little, Brown & Company Limited, Boston.

  • Terres, J. K. 1980. The Audubon Society encyclopedia of North American birds. Alfred A. Knopf, New York.

  • Willard, D. E. 1977. The feeding ecology and behavior of five species of herons in southeastern New Jersey. Condor: Vol. 79, No. 4.

  • Zook, J. L. 2002. Distribution maps of the birds of Nicaragua, Costa Rica, and Panama. Unpublished.

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