Skip to Main Content
Responses of turtle assemblage to environmental gradients in the St. Croix River in Minnesota and Wisconsin, U.S.A.Author(s): Deahn DonnerWright; Michael A. Bozek; John R. Probst; Eric M. Anderson
Source: Canadian Journal of Zoology. 77: 989-1000. (1999)
Publication Series: Scientific Journal (JRNL)
Station: North Central Research Station
PDF: Download Publication (819.97 KB)
DescriptionWe investigated how environmental gradients measured along the St. Croix River in Minnesota and Wisconsin, U.S.A., influenced the turtle assemblage. Among seven species, the five most common species were generalists and had wide distributions throughout the study area. However, patterns in assemblage structure were related to environmental gradients along the river. Sex ratios were male-dominated for the five most common species, and few or no juveniles were captured during the study. The first two canonical axes of a canonical correspondence analysis accounted for 92.7% of the variation in species-environment gradients. Most of the variation in distribution and abundance was attributed to gradients in channel morphology and physical characteristics along the river channel. Abundances of common snapping (Chelydra serpentinal), false map (Graptemys pseudogeographica), and painted (Chrysemys picta bellii) turtles were associated with muck substrates and the number of basking sites (i.e., snags, rocks), which increased farther downstream. Abundance of spiny softshell turtles was closely related to increased water velocity and depth, which veere related to hydraulic control points in the river. Abundance of common map turtles was associated with the presence of open sandy areas, uniform channel bottom, and gravel substrates. Geomorphic changes along the St. Croix River clearly influence the turtle assemblage and these specific relations should be considered in efforts to preserve and restore components of the assemblage.
- Check the Northern Research Station web site to request a printed copy of this publication.
- Our on-line publications are scanned and captured using Adobe Acrobat.
- During the capture process some typographical errors may occur.
- Please contact Sharon Hobrla, email@example.com if you notice any errors which make this publication unusable.
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationDonnerWright, Deahn; Bozek, Michael A.; Probst, John R.; Anderson, Eric M. 1999. Responses of turtle assemblage to environmental gradients in the St. Croix River in Minnesota and Wisconsin, U.S.A. Canadian Journal of Zoology. 77: 989-1000. (1999)
KeywordsSt. Croix River, map turtles, population
- Decline of red-eared sliders (Trachemys scripta elegans) and Texas spiny softshells (Apalone spinifera emoryi) in the Lower Rio Grande Valley of Texas
- GPS Technology for semi-aquatic turtle research
- Translocation as a conservation tool for Agassiz's desert tortoises: Survivorship, reproduction, and movements
XML: View XML