Nerodia rhombifer
(Hallowell 1852)

nĕr-ō-dē-ŭh — rŏm-bĭf-ĕr-ă

An adult Diamond-backed Watersnake from Stafford County. © Edward Arthur?.
Adult Diamond-backed Watersnake from Sedgwick County.  © Mike Everhart?
Image © Suzanne L. Collins, CNAH.
An adult from Barton County. Image © Jim Scharosch.

Harmless. Strongly keeled scales; dark spots shaped like half-moons scattered irregularly on yellow belly; 30–65 narrow dark brown, black or gray bands on a light gray or yellowish gray body. Young same as adults.
The Diamondback Water Snake has a reticulated dorsal pattern. There are rather small light-colored blotches found on the middle of the back and large bars that extend up from the ventral line. There are often small lines that connect the blotches to the bars. All of these markings are brown or grayish. Larger adults may appear solid brown to olive when they are dry, but the pattern is usually discernible on wet individuals.
The tail is ringed and the rings are the same color as the dorsal markings. The belly is entirely yellow to cream anteriorly, changing to yellow with many brown half-moon shaped markings. These markings may be sparse or absent in the center and become much more numerous at the edges of the belly. The labials are bright yellow. Newborn diamondback water snakes look like lighter and brighter versions of the adults.
Adults normally attain 760-1,220 mm (30- 48 inches) in TL; largest specimen from Kansas: female (KU 204483) from Douglas county with TL of 1,415 mm (55½ inches) collected by Gregory Beilfuss on 25 March 1986; heaviest example from state: female (KU 207187) from Lyon County that weighed 1,750 grams (3 pounds, 14 ounces) collected by B. Stapp on 18 May 1987; maximum length throughout range: 69 inches (Boundy, 1995).

Found commonly in farm ponds, reservoirs, and streams along the Kansas (below Manhattan), Marais des Cygnes, Neosho, Verdigris, and Arkansas (below Great Bend) rivers. The Diamondback Water Snake inhabits rivers, sloughs, ponds, backwaters, and oxbows.

(, Museum Voucher) (, Observation) (, Literature Record)
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  • Occurrence Summary:  
  • 272 Total Records 
  • 259 Museum Vouchers 
  • 13 Other Observations 
Some county occurrences indicated below may be too imprecise to map above.
County Breakdown: County Name (# occurrences):
Allen (1); Anderson (1); Barber (4); Barton (19); Bourbon (3); Butler (2); Chautauqua (4); Cherokee (6); Coffey (6); Cowley (8); Crawford (9); Douglas (64); Elk (2); Franklin (31); Greenwood (4); Harper (9); Harvey (2); Kingman (1); Labette (8); Leavenworth (2); Linn (6); Lyon (16); Meade (11); Miami (6); Montgomery (4); Morris (2); Neosho (6); Osage (2); Pratt (1); Reno (1); Riley (1); Sedgwick (1); Shawnee (1); Stafford (4); Sumner (2); Wabaunsee (1); Wilson (2); Woodson (19);

Natural History:
Inhabits permanent lakes, marshes and swamps, and backwaters of rivers. Active from March to September; basks during the day on brush, logs and grassy banks along the edge of the water. In summer, searches for food at night. Large litters, ranging from 13-62 young are usually born from August to early October. Feeds primarily on slow-moving or dead fishes.
Copulation probably takes place right after emergence from hibernation. Many males may court one female at the same time. The females are usually quite a bit larger than the males. The pair usually will select a basking perch such as a shrub or branch overhanging water for copulation. Matings have been observed on the banks or even in the water, however.
During breeding, both snakes may make undulating movements with their bodies and the pair may remain locked up for an hour or more. Young are born alive in late June into August. The young are from 9 - 13 1/8 inches at birth (Conant, 1975) and are pugnacious like the adults. An average of 30 young may be produced in a single litter.

Occurrence Activity:
White dates indicate there is at least a single recorded occurrence on that date. The darker blue a date is, the greater the relative number of observations for that date.
Burt and Hoyle (1935) commented on an encounter with this species in southeast Kansas; "One of these snakes was found at the side of a shallow roadside ditch near a garden and above a culvert in Labette county, Kansas, on April 22, 1933. When discovered it had only the top of its head and its eyes above the surface of the water. The head was seized and the snake attempted to withdraw into a shallow tunnel in the earth. Failing in this it made an effort to disconcert its captor by the use of its nauseating odoriferous secretion as it wound about his arm."

1904 Branson, Edwin B. Snakes of Kansas. University of Kansas Science Bulletin 2(13):353-430
1911 Hurter, Julius. Herpetology of Missouri. Transactions of the Academy of Science St. Louis 20(5):59-274
1913 Crow, H. E. Some trematodes of Kansas snakes. University of Kansas Science Bulletin 7(4):125-136
1914 Dyche, Lewis L. Enemies of fish. Pages 145-158 in Ponds, Pond Fish and Pond Fish Culture State Department Fish and Game Bulletin No. 1, Kansas State Printing Office, Topeka. pp.
1929 Dolman, Katherine. Studies of Kansas Water Snakes. Thesis. University of Kansas, Lawrence. 69pp.
1929 Taylor, Edward H. A revised checklist of the snakes of Kansas. University of Kansas Science Bulletin 19(5):53-62
1932 Gloyd, Howard K. The herpetological fauna of the Pigeon Lake Region, Miami County, Kansas. Papers of the Museum of Zoology, University of Michigan 15():389-408
1935 Burt, Charles E. and William L. Hoyle. Additional records of the reptiles of the central prairie region of the United States Transactions of the Kansas Academy of Science 37():193-216
1937 Grant, Chapman. Herpetological notes from Central Kansas. American Midland Naturalist 18(3):370-372
1956 Diener, Richard A. New records of snakes in southwestern Kansas. The Southwestern Naturalist 1(1):27-29
1956 Loomis, Richard B. The chigger mites of Kansas (Acarina, Trombiculidae). University of Kansas Science Bulletin 37():1195-1443
1962 Gish, Charles D. The Herpetofauna of Ellis County, Kansas. Thesis. Fort Hays State University, Hays, Kansas. 34pp.
1976 Caldwell, Janalee P. and Gregory. Glass. Vertebrates of the Woodson County State Fishing Lake and Game Management Area. Pages 62-76 in Preliminary inventory of the biota of Woodson County State Fishing Lake and Game Management Area. Report No. 5. State Biological Survey of Kansas, Lawrence. pp.
1979 Rundquist, Eric M. Herps observed or collected during the first three months of 1979. Kansas Herpetological Society Newsletter (30):42893
1980 Clarke, Robert F. Herptiles and fishes of the western Arkansas River in Kansas. United States Army Corps of Engineers, Albuquerque, New Mexico. 55pp.
1985 McAllister, Chris T. Nerodia rhombifera. Catalogue of American Amphibians and Reptiles (376):1-4
2000 Taggart, Travis W. Results of the KHS 2000 fall field trip. Kansas Herpetological Society Newsletter (122):6-8
2001 Taggart, Travis W. The KHS 2001 spring field trip: A rainy rendezvous. Kansas Herpetological Society Newsletter (124):12-14
2004 Delisle, Jennifer M. and William H. Busby Biological inventory for vertebrates at Fort Larned National Historic Site of the southern plains network. Natural Heritage Inventory, Kansas Biological Survey, Lawrence. 61pp.
2006 Taggart, Travis W. Distribution and status of Kansas herpetofauna in need of information. State Wildlife Grant T7. Kansas Department of Wildlife and Parks, Pratt. vii + 106pp.
2010 Miller, Larry L. 2010 Investigation of the Checkered Garter Snake in Kansas with notes on other Amphibians, Reptiles, and Turtles encountered. Kansas Department of Wildlife and Parks, Pratt, Kansas. 31pp.
2012 Rohweder, Megan R. Spatial conservation prioritization of Kansas for terrestrial vertebrates. Thesis. Fort Hays State University, Hays, Kansas. 151pp.
Account Last Updated:
6/26/2018 4:24:11 PM

Travis W. Taggart © 2020 — Sternberg Museum of Natural History, Fort Hays State University