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Mississippi River
Least Tern Breeding Colony - Island No. 21

    TWRA symbol

MAVDyer Co.Least Tern Surveys in the Mississippi River

Note: Least Tern breeding colonies that contain >1% of the total inland Least Tern breeding population can qualify as a separate IBA. In Tennessee, the site must meet this requirement 4 out of the last 5 years (2001-2005). Island No. 21 is part of the IBA site, Mississippi Alluvial Valley in Tennessee.

Surveys: Interior Least Tern surveys have been conducted since 1985 by the Memphis District Army Corps of Engineers. In the period 2001-2005, a small boat survey technique was used to census the birds. Upon spotting a likely colony, terns were counted in the air and on the land from the boat as it drifted downstream. After this preliminary count, the site was usually surveyed on foot to count adults, nests, eggs, and chicks. (Jones 2005).  See Least Tern Surveys in the Mississippi River for a summary and each county for a county breakdown--Lake County and Obion County, Dyer County, Lauderdale County, Tipton County, and Shelby County.

Location:  Island No. 21, Dyer County, Tennessee
Physiographic Province:  PIF 05 (Mississippi Alluvial Valley); BCR 26 (Mississippi Alluvial Valley)
Tennessee IBA Site Map - MR Island No. 21.bmp (80006 bytes)
Geographical Coordinates:
    Island No. 21--Lat. 35.9624N  Long. 0897101W
Elevation Range:
    236' Island No. 21
Size:  acres
USGS 7.5' quad:  Chic

Description: 

YEARSubstrateVegetationVegetation To Nearest Nest
(feet)
2005Sand/DebrisWillows/Grass200'
2004SandWillows/Grass100'
2003Sand/DebrisWillows/Grass300'
2002SandWillows100'
2001SandWillows/Cottonwoods1,000'

IBA Criteria:  1

Ornithological Importance:  Nest site of inland race of Least Tern, a Tennessee and Federal Endangered species, containing >1% of the total inland Least Tern population for that year.
    Note 1. 2005. Surveyed June 26. Nesting on left bank, approximately 100 feet from center of nest site to the river. Adults: 102. Eggs: 1,2 egg clutches. Nests: 10, Chicks: No. "High, barely attached, steep, narrow, point bar. Colony concentrated on highest point., but also utilizing lower more recently exposed sand. Human and coyote tracks abundant with predation leaving many egg shell fragments. Thirty-five Killdeer." Map No. 44, A-I-12. Field Data Sighting Sheet A-II-25 (Jones 2005).
    Note 2. 2004. Surveyed July 23. Nesting on left bank, approximately 100 feet from center of nest site to the river. Adults: 353. Eggs: 2 egg clutches. Chicks: Yes. "High, unattached, steep, narrow, point bar. Colony concentrated on highest point, but also utilizing lower more recently exposed sand. chicks of all ages up to 2 weeks. Dog or coyote tracks abundant and deer tracks. One egg and scrape located in plastic, corrugated pipe segment (photo taken)." TN side. Map No. 43, A-I-10. Field Data Sighting Sheet A-II-24 (Jones 2004).
    Note 3. 2003. Surveyed July 14. Nesting on left bank, approximately 250 feet from center of nest site to the river. Adults: 85. Eggs: 1,2,3 egg clutches. Chicks: Yes. "High, unattached, narrow, point bar. Several abandoned eggs, but many more in active scrapes, some associated with wrack line down center of colony. Chicks all ages up to 1 week, adults breasting and feeding on channel side. No tracks or other signs of disturbance." TN side.  Map No. 43, A-I-11. Field Data Sighting Sheet A-II-30 (Jones 2003).
    Note 4. 2002. Surveyed July 8. Nesting on left bank, approximately 200 feet from center of nest site to the river. Adults: 59. Eggs: 3 egg clutches. Chicks: No. "High, long, flat, clean, unattached bar with small wrack line. Four terns along waterline downstream from colony. No signs of any disturbance. Twelve Great blue Herons at waterline in back chute. TN side. Map A-I-11. Field Data Sighting Sheet A-II-26 (Jones 2002).
    Note 5. 2001. Surveyed July 19. Nesting on left bank, approximately 500 feet from center of nest site to the river. Adults: 63. Eggs: 3 egg clutches. Chicks: Yes. "Isolated, flat, clean, high, sandbar with chicks 1 to 2 weeks old. One chick banded and blood sampled. Coyote and Great blue Heron tracks. Scrapes with eggs at bar's center." TN side. Map A-I-10. Field Data Sighting Sheet A-II-47 (Jones 2001).

River Mile

2005
(Total Inland Population/>1%)
9,563/94 (a)
10,960/110 (b)

2004
(Total Inland Population/>1%)
9,061/91 (a)
11,239/112 (b)

2003
(Total Inland Population/>1%)
8,082/81 (a)

2002
(Total Inland Population/>1%)
5,802/58 (a)

2001
(Total Inland Population/>1%)
6,361/64 (a)

Source2

825.5102
(See Note 1 above.)		353------7
825.4------59637
825.2----85----7
(a) Least Tern survey 2001-2003 was from Cape Girardeau, Missouri to Vicksburg, Mississippi, for a total of 577 river miles.
Number reflect survey of 577 river miles.
(b) Least Tern survey 2004-2005 was extended 200 miles to Baton Rouge, Louisiana, for a total of 777 river miles.
Numbers reflect extended survey to 777 river miles.
Season1   B = Breeding, W = Wintering, SM = Spring Migration, FM = Fall Migration 
Source 2  1-Atlas Breeding Birds of Tennessee 2-Breeding Bird Surveys 3-Christmas Bird Counts
4-Point Counts 5-Refuge Counts 6-Personal observations 7-Other (Ken Jones, John Rumancik, et al.)

Ownership:  US Army Corps of Engineers
     Contact:  John Rumancik, Department of the Army, Memphis District Corps of Engineers, 167 North Main Street, B-202, Memphis, TN 38103-0894, (901) 544-3975,  John.P.Rumancik@mvm02.usace.army.mil.

Conservation Concerns:  Major concerns are predation and disturbance to birds.

Management Program:

Submitted by:

Additional Contributors:  Kenneth H. Jones, Associate Professor of Biology, Dyersburg State Community College, 1510 Lake Road, Dyersburg, TN 38024, 731-286-3367, kjones@dscc.edu.   John Rumancik, Department of the Army, Memphis District Corps of Engineers, 167 North Main Street, B-202, Memphis, TN 38103-0894, 901-544-3975,  John.P.Rumancik@mvm02.usace.army.mil.

References:
Jones, K. H. 2005. Population Survey of the Interior Least Tern on the Mississippi River from Cape Girardeau, Missouri to Baton Rouge, Louisiana. Memphis District, Corps  of Engineers.
Jones, K. H. 2004. Population Survey of the Interior Least Tern on the Mississippi River from Cape Girardeau, Missouri to Baton Rouge, Louisiana. Memphis District, Corps  of Engineers.
Jones, K. H. 2003. Population Survey of the Interior Least Tern on the Mississippi River from Cape Girardeau, Missouri to Vicksburg, Mississippi. Memphis District, Corps  of Engineers.
Jones, K. H. 2002. Population Survey of the Interior Least Tern on the Mississippi River from Cape Girardeau, Missouri to Vicksburg, Mississippi. Memphis District, Corps  of Engineers.
Jones, K. H. 2001. Population Survey of the Interior Least Tern on the Mississippi River from Cape Girardeau, Missouri to Vicksburg, Mississippi. Memphis District, Corps  of Engineers.

Approved under the umbrella IBA site Mississippi Alluvial Valley:  February 2006--Yes 7  No 0

This page was last updated on 02/19/06.