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Mississippi River
Least Tern Breeding Colony - Island No. 18
Towhead Dikes

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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. 18 Towhead Dikes 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. 18 Towhead Dikes, two river miles south of I-155 bridge, Dyer County, Tennessee.
Physiographic Province:  PIF 05 (Mississippi Alluvial Valley); BCR 26 (Mississippi Alluvial Valley)
Tennessee IBA Site Map - MR Island No. 18 TD.bmp (80006 bytes)
Geographical Coordinates:
     Island No. 18--2005. Lat. 360908N  Long. 0896683W
     Island No. 18--2004. Lat. 360908N  Long. 0896683W
     Island No. 18--2003. Lat. 360925N  Long. 0896668W
     Island No. 18--2002. Lat. 360548N  Long. 0893941W
     Island No. 18--2001. Lat. 360546N  Long. 0893945W

Elevation Range:
     about 243' Island No. 18
Size:  acres
USGS 7.5' quad: Tennemo

Description: 

YEARSubstrateVegetationVegetation To Nearest Nest
(feet)
2005SandWillows1,000'
2004SandWillows100'
2003Sand/DebrisWillows500'
2002SandWillows400'
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 site on left bank, approximately 500 feet from the river to the center of the nest site. Adults: 270. Eggs: 1,2,3 egg clutches. Chicks: Yes. "Unattached, medium size, high, solid sand bar with large, widely dispersed colony (1.5 x .25 miles). Chicks up to 10 days old. Breasting behavior observed, but no tracks or other disturbance factors." TN Side. Map 42, A-I-11. Field Data Sighting Sheet A-II-22. (Jones 2005)
    Note 2. 2004. Surveyed July 23. Nesting site on left bank, approximately 150 feet from the river to the center of the nest site. Adults: 450. Eggs: 2,3 egg clutches. Chicks: Yes. "Unattached, medium size, high sand bar (15 ft.) with large, very concentrated colony on high, downstream point. chicks up to one week old are abundant as are nests with 3 eggs hatching underway. Birds feeding on both sides. Colony was visited 7/15/04 when first hatching was occurring. Deer tracks and many shad fingerlings, fishing boat in back chute. On inch rainfall previous night." TN Side. Map 42, A-I-9. Field Data Sighting Sheet A-II-19. (Jones 2004)
    Note 3. 2003. Surveyed July 14. Nesting site on left bank, approximately 500 feet from the river to the center of the nest site. Adults 225. Eggs: 2 egg clutches. Chicks: Yes. "High, undulating bar with wrack lines and ridges containing nests, many abandoned. Colony 1/2 mile long and wide, with eggs hatching and young 1,2,3 day old chicks. Fishing on both sides. Heavy human signs, turtle tracks. This bar was visited on month earlier and many scrapes with eggs were observed then." Map 42, A-I-10. Field Data Sighting Sheet A-II-25. TN Side. (Jones 2003)
    Note 4. 2002. Surveyed July 8. Nesting site on left bank, approximately 500 feet from the river to the center of the nest site. Adults 202. Eggs: 3 egg clutches. Chicks: Yes. "Long, high, flat, unattached sand bar with willows at lower, high end. Colony concentrated at high center of bar just upstream from wooded portion. Many nests with 3 eggs observed during preliminary visit 6/18/02. Breasting and feeding both sides with newly hatched chicks in many scrapes, some seeking shelter in shade of young forbs. Some nests along wrack lines. Fresh human tracks and camping remains. Seven Great Blue Herons. TN side." TN Side. Map A-I-13. Field Data Sighting Sheet A-II-22. (Jones 2002)
    Note 5. 2001. Surveyed July 19. Nesting site on left bank, approximately 500 feet from the river to the center of the nest site. Adults 150. Eggs: 1,2,3 egg clutches. Chicks: Yes. "Large, flat, gently sloping sand bar with small scattered willow and cottonwood seedlings. Tall timber over 3/4 mile away. Chicks abundant from 1 to 7 days old. Two chicks banded and blood sampled. No signs of recent predators or recreational use. Shad and fingerling sunfish. Several dead chicks maybe due to recent heavy rains." TN Side. Map A-I-9. Field Data Sighting Sheet A-II-43. (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

835.5

----225
(See Note 3 above.)		202
(See Note 4 above.)		--7

835

--450
(See Note 2 above.)		------7

836

270
(See Note 1 above.)		------150
(See Note 5 above.)		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.