Illinois Natural History Survey - University of Illinois

Least tern
Sterna antillarum

 

Taxonomy
Occurence in Illinois
Status
Habitat associations
Guilds
Food-habits
Environmental associations
Life history
Management practices
References


TAXONOMY

 

  • Phylum: Chordata
  • Class: Aves
  • Order: Charadriiformes
  • Family: Laridae
  • Genus: Sterna
  • Species: Sterna antillarum
  • Authority: Lesson

Comments on taxonomy:
Least tern, Sterna antillarum is split from the little tern, S. albifrons which is confined to the old world *15,18*. The interior least tern, S.a. anthalassos, is found in Illinois *05,18*. Mengel (1965) did not recognize S.a. anthalassos at Bell I *12*. For other common names see *03*.

 


OCCURENCE IN ILLINOIS

Mid May-early Sept.; uncommon local migrant and summer resident in south, rare migrant and post-breeding wanderer in remainder of state. No evidence of nesting in Illinois since 1974 at Cairo, Ill., Even these were probably post-breeding wanderers (see 21-28). Two historical nesting colonies: 1 on Bell I, in Ohio River near Shawnee Town, Galatin Co.; 1 on Mosenthein I, in Mississippi River near E. St. Louis, Madison Co. *02*.

 


STATUS

Items in bold indicate applicable categories
Forest Service Categories: S = recommended for regional sensitive status, F = forest listed species, M = management indicator species

Federal Status:

Endangered Threatened Proposed for listing
Candidate for proposal Recovery plan approved Recovery plan received (USFWS)
Recovery plan in preparation Under notice of review Delisted
Migratory EPA indicator Forest Serv.- Shawnee species

State Status:

Endangered Threatened Proposed

Other:

Game Furbearer Nongame protected
Sportfish Commercial Pest None of the above

Comments on status:
Named on Illinois endangered species list in 1977. See *02*. Also protected under Illinois Wildlife Code 1971 *29* and Migratory Bird Treaty Act 1918 *20*. The interior least tern (S.a. anthalassos) currently is being considered for federal listing under category 2, federal register VOL.47., 1982 *30*.

 


HABITAT ASSOCIATIONS

Items in bold indicate applicable categories

General habitat:

Unknown Terrestrial Aquatic Riparian

USFS timber inventory forest size class:

Unknown Unstocked Seedling Sapling
Seedling/sapling Pole Mature Over mature

Land use and land cover:

Unknown   Urban Residential
Commercial
Industrial
Transportation, communication
Complex industrial/commercial
Mixed
Other
Agricultural Crop, pasture
Orchards, groves, nurseries
Feedlot
Other
Rangeland Herbaceous
Shrub and brush
Mixed
Forestland Deciduous
Evergreen
Mixed
Water Stream
Lake
Reservoir

Bay
Wetland Forest
Non-forest
Barren Salt flat
Beach
Sand

Rock
Mine
Transit
Mix

 


Forest cover types: No records.

Associated tree species: No records.

National wetland inventory classifications:

SystemSubsystemClassSubclassWater regime modifiersWater chemistry
Lacustrine Littoral Beach/bar Cobble/gravel Permanent nontidal Freshwater
Lacustrine Littoral Beach/bar Sand Permanent nontidal Freshwater
Riverine Lower perennial Beach/bar Cobble/gravel Permanent nontidal Freshwater
Riverine Lower perennial Beach/bar Sand Permanent nontidal Freshwater

Comments on species-habitat associations:
In illinois nested on sand bars in Mississippi and Ohio River *02*.

Important plant and animal association: Small fishes.
Principle, almost exclusive food item *05,14*.

High value habitats

HabitatStructural stageSeason
Beaches Special habitat Spring/summer
Lakes and ponds Special habitat Summer
Low-gradient large river Special habitat Spring/summer

Species-habitat interrelations: Requirements for location of interior least tern colonies include 1) presence of sandbars, 2) existence of favorable water levels, 3) availability of food. For more details see *05*.

 


GUILDS

Feed-guilding:

HabitatStructural stageSeasonFeed-guilds
Lakes and ponds Special habitat Summer Water surface- fish
Water column- fish
Low-gradient large river Special habitat Spring/summer Water surface- fish
Water column- fish

Comments on feed-guilding:
No comments.

Breed-guilding:

HabitatStructural stageSeasonBreed-Guilds
Low-gradient large river Special habitat Spring/summer Surface of water column-river/lake/marsh, unconsolidated sand substrate
Terrestrial surface, beaches (mud, sand, rock) without hydrophytes
Terrestrial surface, bare ground (sand to rubble)
Beach Special habitat Spring/summer Surface of water column-river/lake/marsh, unconsolidated sand substrate
Terrestrial surface, beaches (mud, sand, rock) without hydrophytes
Terrestrial surface, bare ground (sand to rubble)

Comments on breed-guilding:
Courtship rarely takes place in ternery *05*. Copulation may take place on beaches or water surface *05,11*. Later phases take place on sandbar and adjacent shallows *05*.

 


FOOD-HABITS

Trophic level is CARNIVORE

Food itemLife stage/plant part
Osteichthyes (bony fishes) Unknown
Cypriniformes (carps, minnows, loaches) Unknown
Important:
Osteichthyes (bony fishes) Unknown
Cypriniformes (carps, minnows, loaches) Unknown
Juvenile:
Osteichthyes (bony fishes) Unknown
Cypriniformes (carps, minnows, loaches) Unknown
Adult:
Osteichthyes (bony fishes) Unknown
Cypriniformes (carps, minnows, loaches) Unknown

Comments on food habits: 
General: In Illinois the least tern feeds almost wholly on small fishes, almost invariably the river shiner at Bell I. See *05,13*
Juvenile: Almost solely small fishes *05,06,11*
Adult: See [FH].


ENVIRONMENTAL ASSOCIATIONS

General:

  • Air temperature:see comments
  • Biodegradable organics: clean waters that have not been polluted
  • Aquatic habitat zone: pelagic- needs open water
  • Water level: see comments
  • Aquatic habitats: sandy beaches
  • Aquatic habitats: sandbars
  • Aquatic habitats: island inhabitant
  • Aquatic habitats: sloughs, bayous
  • Aquatic habitats: oxbow
  • Aquatic habitats: backwaters

Limiting:

  • Air temperature:see comments
  • Biodegradable organics: clean waters that have not been polluted
  • Aquatic habitat zone: pelagic- needs open water
  • Water level: see comments
  • Aquatic habitats: sandy beaches
  • Aquatic habitats: sandbars

Egg

  • Air temperature: see comments

Feeding juvenile:

  • Biodegradable organics: clean waters that have not been polluted
  • Aquatic habitat zone: pelagic- needs open water
  • Aquatic habitats: sloughs, bayous
  • Aquatic habitats: oxbow
  • Aquatic habitats: backwaters

Resting juvenile:

  • Aquatic habitats: sandy beaches
  • Aquatic habitats: sandbars

Feeding adult:

  • Biodegradable organics: clean waters that have not been polluted
  • Aquatic habitat zone: pelagic- needs open water
  • Aquatic habitats: sloughs, bayous
  • Aquatic habitats: oxbow
  • Aquatic habitats: backwaters

Resting adult:

  • Aquatic habitats: sandy beaches
  • Aquatic habitats: sandbars

Breeding adult:

  • Biodegradable organics: clean waters that have not been polluted
  • Water level: see comments
  • Aquatic habitats: sandbars
  • Aquatic habitats: sloughs, bayous
  • Aquatic habitats: oxbow
  • Aquatic habitats: backwaters

Comments on environmental associations:
General: In Illinois invariably associated with large rivers with sandbars.
Egg: Eggs partly incubated by sun. Viable incubation temperatures range from 95.4-102 degrees F, optimum 98.4 degrees F.
Feeding juvenile: See [FA]. Receive food at colony when flightless, later travel with parents to fishing areas *05*.
Resting juvenile: Lie prostrate on sand, gather on sand bars *05,06,17*.
Feeding adult: Hunt over river near colony, about nearby sloughs, backwaters and ox-bow lakes *05,12*.
Resting adult: Roost on beaches at night, rest on old logs, drift accumulations, beaches and sand bars after breeding season *05,06,08,11*.
Breeding adult: Limiting requirements: 1) presence of sandbars, 2) existence of favorable water levels, 3) availability of food *05*.


LIFE HISTORY

Origin: Native *01,15*

Physical description: Smallest of American terns. Length 8 1/2-9 1/2 in.; wingspread 20 in. female smaller. sexes alike. Breeding adult: body white, black-capped with white forehead, yellow bill with black tip, yellow feet. Black leading edge of wing. Immature & winter adult: nape with line to eye dark, dark bill, feet yellow. Immatures have much black on forewing *03,19*.

Reproduction: Breeds in Illinois early June-late July *05*. For history of nesting in Illinois see *08*. If arrive and nesting site immersed, feed and rest nearby. Courtship begins here but is halted until emergence of sand bar which may help synchronize breeding activities *05*. Courtship ritualized & includes aerial glide & posturing parade. For description see *05,11*. In Ga. began immediately and lasted 20 days. Courtship not performed in ternery. Copulation on land or water, often exchange fish, duration 3 sec. *05*. Unclear who chooses territory, or if established before nest. Female makes final nest scrape *11*. Nest - simple shallow depression in sand or gravel *03,05,13*. Eggs are variable, pale to olive buff, spotted from lilac to dark brown. Dimensions approx. 31 x 23.5 mm *03,05,13*. Ave. clutch size 2 or 3 (1-4). 3 Egg clutches in north, 2 egg in south part of range *03,05,11,12,13*. Eggs layed on consecutive days *05,11*. Incubation begins soon after 1st egg layed *05*. Both sexes incubate mean = 20 days *05,11,12*. Hatchling covered with cryptic down weighing approx 4.9 g *05*. For growth & development of young and parental care see *05*. Some post-breeding wandering *05*. Family groups may be maintained through migration *05,11*. Usually 1 brood/ year *03,06*. Suggested may raise 2 or 3 in warmer climate *03,04*. Male and female attain sexual maturity at 2 yrs. *11,17*. Maximum breeding age unknown.

Behavior: Least tern is a migrant, present in Ill. From late May- early Sept. *01*. Are not as colonial as some tern spp., nesting in well scattered groups. See *05* for density in Ill. Areas within few feet of nest are defended by both sexes, with the space between nests neutral *05*. Home range unknown, but carried fish from 16,000 ft., see *06*. Post-fledging young flew 5 km off colony to roost *17*. When young able to fly, terns desert colony, feeding along river near nesting area, eventually wander along rivers and about lakes several wks. before migration *05*. Apparently, migrate in family groups *05,11*. California least terns do not return to natal site see *11*. Preferred fishing sites occur along sandbar or colony during breeding season and extend along river and accompanying waters later in season *05*. Visciously attack intruders, but not as aggressive as other tern spp *04*.

Limiting factors: Sandbars are preferred nesting habitat. Water levels dictate start of breeding activities *05*. Severe floods may delay or prevent nesting. Colony at St. Louis was consistently flooded and apparently abandoned *21-28*. River alterations *02,03, 05,16*. Human disturbance *02,03*. Enemies *03,05,09,11*. Pollution *09*. Requirements for location of ternery 1) presence of sandbars, 2) existence of favorable water levels, 3) availability of food *05*.

Population parameters: Relative trend in Illinois is down. Last successful nesting possibly 1977 *27*. Mississippi River population 150 mi. south of Cairo, Il. appears flourishing, est. 600 birds *16*. River alterations could cause decrease. Hager (1937) in Hardy reported mortality to be highest from hatching to fledging, 9% reaching flying stage (n=212) *05*. For Bell I., Il., 65% hatching success, of 55 chicks 2 or 3.6% survived to flying stage see *05*. Hardy (1957) reports low adult mortality *05*. Ratio of 1 yng to 4 adults observed in 1957 after breeding season *05*. Marples (1934) assumed ave. lifespan 5 years, reasoning if each female lay 11 eggs during lifetime, only 2 would need to survive to maintain the population, therefore approx. 70% mortality could be tolerated *05*. Fledging success considered good if 1.0-1.5, moderate at 0.5-1.0, poor 0-0.5 *17*. Oldest individual, 21 yrs. 01 mos. *10*. Sex ratio unknown.

 


MANAGEMENT PRACTICES

Beneficial:

  • Maintaining undisturbed/undeveloped areas
  • Maintaining early stage of ecological succession
  • Maintaining natural areas and nature preserves
  • Maintaining unique or special habitat features (wetlands, snags, caves, cliffs, talises, etc.)
  • Preserving endangered species habitat
  • Preserving sensitive species habitat
  • Performing special survey prior to prescription
  • Performing field survey prior to prescription
  • Controlling land use and human activities
  • Seasonal restriction of human use of habitats
  • Controlling pollution
  • Controlling pollution in aquatic habitats
  • Controlling water levels
  • Creating artificial islands or rafts
  • Developing/maintaining lakes and ponds
  • Creating/maintaining islands within permanent impoundments
  • Developing/maintaining wetlands
  • Protecting existing wetlands
  • Restricting human disturbance during migration, breeding, and nesting
  • Maintaining undisturbed resting areas for migrating birds
  • Developing islands for waterfowl

Adverse:

  • Recreational development
  • Channelization
  • Navigational improvements such as channelization and locks and dams
  • Dredging
  • Providing public access (develop roads, trails, parking areas or provide legal access)

Comments on management practices:
For management recommendations for Illinois see *02,05*. Nest site manipulation see *07*. For demise and management in Calif. see *11*. Least tern is protected by the Illinois Endangered Species Act 1972, *02*, Migratory Bird Treaty Act 1918 *20*, & Illinois Wildlife Code 1971 *29*.

 


REFERENCES

0. MALMBORG, P.L. 1984. IL. NAT. HIST. SURV., 607 E. PEABODY DR., CHAMPAIGN, ILL. (217)333-6846.

1. BOHLEN, H. 1978. AN ANNOTATED CHECK-LIST OF THE BIRDS OF ILLINOIS. ILLINOIS STATE MUS. POP. SCI. SER., VOL. IX. 156 P.

2. BOWLES, M.L., V.E. DIERSING, J.E. EBINGER AND H.C. SCHULTZ, EDS. 1981. ENDANGERED AND THREATENED VERTEBRATE ANIMALS AND VASCULAR PLANTS OF ILLINOIS. ILLINOIS DEPT. CONSERV. 189 P.

3. TERRES, J. 1980. AUDUBON SOCIETY: ENCYCLOPEDIA OF NORTH AMERICAN BIRDS. ALFRED KNOPF, NEW YORK. 1109 P.

4. BENT, A.C. 1921. LIFE HISTORIES OF NORTH AMERICAN GULLS & TERNS. U.S. NATL. MUS. BULL. NO. 113.

5. HARDY, J.W. 1957. THE LEAST TERN IN THE MISSISSIPPI VALLEY. PUBL. MUS. MICH. ST. UNIV. BIOL. SER. VO. 1. 60 P.

6. TOMKINS, I.R. 1959. LIFE HISTORY NOTES ON THE LEAST TERN. WILSON BULL. 7(1):313-322.

7. LOFTIN, R.W. & L.A. THOMPSON. 1979. AN ARTIFICIAL NEST STRUCTURE FOR LEAST TERNS. BIRD-BANDING 50(2):163-164.

8. BREWER, R. 1954. NESTING OF THE LEAST TERN IN ILLINOIS. WILSON BULL. 66(3):223.

9. BLUS, L.J. & R.M. PROUTY. 1979. ORGANO CHLORINE POLLUTANTS AND POPULATION STATUS OF LEAST TERNS IN SOUTH CAROLINA. WILSON BULL. 91(1):62-71.

10. KENNARD, J.H. 1975. LONGEVITY RECORDS OF NORTH AMERICAN BIRDS. BIRD- BANDING 46(1):55-73.

11. MASSEY, B.W. 1981. A LEAST TERN MAKES A RIGHT TERN. NATURAL HIST. 90 (11):62-71.

12. MENGEL, R. 1965. THE BIRDS OF KENTUCKY. ORNITH. MONOGR. NO. 3. 581 P.

13. SPRUNT, A. AND E. CHAMBERLAIN. 1970. SOUTH CAROLINA BIRD LIFE. UNIV. SOUTH CAROLINA PRESS, COLUMBIA 655 P.

14. MARTIN, A., H. ZIM AND A. NELSON. 1951. AMERICAN WILDLIFE AND PLANTS. MCGRAW-HILL BOOK CO., NEW YORK. 500 P.

15. AMERICAN ORNITHOLOGISTS' UNION. 1982. THIRTY-FOURTH SUPPLEMENT TO THE AMERICAN ORNITHOLOGISTS' UNION. CHECK-LIST OF NORTH AMERICAN BIRDS. SUPPLEMENT AUK 99(3).

16. DOWNING, R.L. 1980. SURVEY OF INTERIOR LEAST TERN NESTING POULATIONS. AMERICAN BIRDS 34(2):209-211.

17. MASSEY, B.W., & J.L. ATWOOD. 1981. SECOND-WAVE NESTING OF THE CALIFORNIA LEAST TERN: AGE COMPOSITION AND REPRODUCTIVE SUCCESS. AUK 98:596-605.

18. DEBENEDICTIS, P.A. 1983. COMING. A NEW OFFICIAL CHECK-LIST OF NORTH AMERICAN BIRDS - A REVOLUTION IN AVIAN NOMENCLATURE. AMERICAN BIRDS 37(1):3-8.

19. PETERSON, R. 1980. A FIELD GUIDE TO THE BIRDS. 4 ED. HOUGHTON-MIFFLIN CO., BOSTON. 384 P.

20. U.S. FISH AND WILDLIFE SERVICE. 1983. CODE OF FEDERAL REGULATIONS. TITLE 50. WILDLIFE & FISHERIES. CHAPTER 1, PP 11-18, 50CFR10.13. LIST OF MIGRATORY BIRDS. SPECIAL PUBL. FEDERAL REGISTER. GENERAL SER- VICES ADMIN. OCTOBER 1.

21. KLEEN, V.M. 1981. FIELD NOTES: BREEDING SEASON. ILLINOIS AUDUBON BULL. 195:34-47.

22. KLEEN, V.M. 1983. FIELD NOTES: BREEDING SEASON. ILLINOIS AUDUBON BULL. 203:25-39.

23. KLEEN, V.M. 1982. FIELD NOTES: BREEDING SEASON. ILLINOIS AUDUBON 199:21-39.

24. KLEEN, V.M. 1983. FIELD NOTES: FALL MIGRATION. ILLINOIS AUDUBON BULL. 204:45-56.

25. KLEEN, V.M. 1979. FIELD NOTES: BREEDING SEASON. ILLINOIS AUDUBON BULL. 187:27-35.

26. KLEEN, V.M. 1978. FIELD NOTES: BREEDING SEASON. ILLINOIS AUDUBON BULL. 183:30-37.

27. KLEEN, V.M. 1977. FIELD NOTES: BREEDING SEASON. ILLINOIS AUDUBON BULL. 179:34-40.

28. KLEEN, V.M. 1975. FIELD NOTES: BREEDING SEASON. ILLINOIS AUDUBON BULL. 171:16-18.

29. ILLINOIS DEPARTMENT OF CONSERVATION. 1980. CONSERVATION LAWS. CH. 61. WILDLIFE. ART. II. PAR. 2.2. REPRINTED FROM ILLINOIS REVISED STATUTES. 1979. WEST PUBL. CO., ST. PAUL, MN. 123P.

30. U.S. DEPT. OF INTERIOR, FISH AND WILDLIFE SERVICE [USDI]. 1982. EN- DANGERED AND THREATENED WILDLIFE AND PLANTS; REVIEW OF VERTEBRATE WILDLIFE FOR LISTING AS ENDANGERED AND THREATENED SPECIES. FED. REG. 47(251): 58454-58460.

 


 

Next ---- Previous



Illinois Natural History Survey

1816 South Oak Street, MC 652
Champaign, IL 61820
217-333-6880
cms@inhs.illinois.edu

Terms of use. Email the Web Administrator with questions or comments.

© 2019 University of Illinois Board of Trustees. All rights reserved.
For permissions information, contact the Illinois Natural History Survey.

Staff Intranet
Login