Lake Erie Watersnake

Post-Delisting Monitoring Plan for the Lake Erie Watersnake (Nerodia sipedon insularum) on the Offshore Islands of Western Lake Erie

 

Below are the Table of Contents, Introduction, and Background sections of the Plan. Download a PDF version of the complete 34-page Lake Erie Watersnake Post-Delisting Monitoring Plan.

 

 

Prepared by

the U.S. Fish and Wildlife Service Ohio Ecological Services Field Office, Columbus, OH
and
Dr. Richard King, Northern Illinois University

January 27, 2011

 

Table of Contents

 

List of Figures .................................................................................................................... ii

List of Tables .................................................................................................................... iii
I. Introduction .................................................................................................................. 1
II. Background ................................................................................................................. 1
III. Brief summary of the roles of all cooperators in the PDM planning effort ................... 3

A. U.S. Fish and Wildlife Service...................................................................................... 3
B. Ohio Department of Natural Resources, Division of Wildlife ............................................ 3

 

IV. Summary of species’ status at time of delisting ............................................................... 4

A. Demographic parameters .......................................................................................... 4
B. Residual threats ....................................................................................................... 7
C. Legal and management commitments for post-delisting conservation ..................... ........9

 

V. Monitoring methods, including sampling considerations ...................................................... 11

A. Estimates of adult Lake Erie Watersnake population size .....................................................11
B. Status of Lake Erie Watersnakes on small U.S. islands ........................................................14
C. Estimates of annual survival of adult Lake Erie Watersnakes ............................................... 15
D. Estimates of the realized population growth parameter for adult Lake Erie
Watersnakes .................................................................................................................. 15
E. Lake Erie Watersnake diet composition .................................................................. 15
F. Round goby local abundance ................................................................................... 16
G. Public opinion surveys ............................................................................................ 16
H. Protected habitat monitoring ................................................................................... 17
I. Voluntary guideline implementation monitoring ..................................................... 17

 

VI. Definition of thresholds/triggers for potential monitoring outcomes and
conclusions ....................................................................................................................... 17
VII. Data compilation and reporting procedures and responsibilities ..................... 20

A. Annual reports ......................................................................................................... 20
B. Round goby local abundance .................................................................................. 21
C. Public opinion survey .............................................................................................. 21
D. Protected habitat and voluntary guideline implementation monitoring .................. 21

 

VIII. Funding ................................................................................................................. 22
A. Estimated funding requirements ............................................................................. 22
B. Potential funding sources ........................................................................................ 22
C. Anti-Deficiency Act disclaimer .............................................................................. 22

 

IX. PDM implementation schedule .............................................................................. 24

X. Conclusion of PDM ................................................................................................... 24

XI. Review and adaptation of PDM plan ..................................................................... 25

XII. Literature cited ....................................................................................................... 26

 

List of Figures

Figure 1. Historic range of Lake Erie Watersnake within the western Lake Erie basin of
Ohio and Canada………………………………………………………………………................................................5

 

List of Tables

Table 1.
Total estimated U.S. Adult Lake Erie Watersnake population size, 2001-2008……….................7
Table 2.
Lake Erie Watersnake protected habitat……………………………………………….....................10
Table 3.
Numbers of adult Lake Erie watersnakes captured, checked for marks, marked, and
released at 14 intensive study sites, 1996-2008………………………………………...............13
Table 4.
Years in which presence of Lake Erie watersnakes has been confirmed on five small
U.S. islands…………………………………………………………………………......................................14
Table 5.
Estimated funding requirements for completing PDM for the Lake Erie
Watersnake……………………………………………………………………………....................................23
Table 6.
General schedule for post-delisting monitoring of the Lake Erie Watersnake.………...24

 

Appendix

 

Responses to public comments on Draft Post-Delisting Monitoring Plan
for the Lake Erie Watersnake (Nerodia sipedon insularum) on the Offshore
Islands of Western Lake Erie……………………………………………………………..........................29

 

 

I. Introduction

Post-delisting monitoring (PDM) refers to activities undertaken to verify that a species delisted due to recovery remains secure from risk of extinction after the protections of the Endangered Species Act (ESA) no longer apply. One primary goal of PDM is to monitor the species to ensure the status does not deteriorate, and if a substantial decline in the species (numbers of individuals or populations) or an increase in threats is detected, to take measures to halt the decline so that re-listing it as a threatened or endangered species is not needed.

 

Section 4(g) of the ESA requires the U.S. Fish and Wildlife Service (Service) to implement a system in cooperation with the States to monitor for not less than five years the status of all species that have recovered and been removed from the list of threatened and endangered plants and animals (list). Section 4(g)(2) of the ESA directs the Service to make prompt use of its emergency listing authorities under section 4(b)(7) of the ESA to prevent a significant risk to the well-being of any recovered species. While not specifically mentioned in section 4(g) of the ESA, authorities to list species in accordance with the process prescribed in sections 4(b)(5) and 4(b)(6) may also be used to reinstate species on the list, if warranted.

 

The Service and States have latitude to determine the extent and intensity of PDM that is needed and appropriate. The ESA does not require the development of a formal PDM “plan.” However, the Service generally desires to follow a written planning document to provide for the effective implementation of section 4(g) by guiding collection and evaluation of pertinent information over the monitoring period and articulating the associated funding needs. Thus this document was prepared to describe the PDM plan for the Lake Erie Watersnake (Nerodia sipedon insularum). This PDM plan follows the Post- Delisting Monitoring Plan Guidance Under the Endangered Species Act (Services 2008; available on-line at http://www.fws.gov/endangered).

 

II. Background

The Lake Erie Watersnake is a subspecies of the Northern Watersnake (N. sipedon sipedon) that occurs primarily on the offshore islands of western Lake Erie in Ohio and Ontario, Canada, but also on a small portion of the U.S. mainland on the Catawba and Marblehead peninsulas of Ottawa County, Ohio (Conant and Clay 1937, p. 2; King 1986, p. 760). Lake Erie Watersnakes are uniformly gray or brown, and have either no banding pattern, or have blotches or banding that are either faded or reduced (Conant and Clay 1937, pp. 2-5; Camin and Ehrlich 1958, p. 504; King 1987, pp. 243-244). Female Lake Erie Watersnakes grow up to 1.1 meters (m) (3.5 feet (ft)), long, and are larger than males (King 1986, p. 762). Newborn Lake Erie Watersnakes are the size of a pencil, and are born during late summer or early fall (King 1986, p. 764).

 

Lake Erie Watersnake summer habitat is composed of rocky shorelines with limestone or dolomite shelves, ledges, or boulders for sunning and shelter. Shelter occurs in the form of loose rocks, piled rocks, or shelves and ledges with cracks, crevices, and nearby vegetation. Rip-rap erosion control, armor stone, and docks incorporating a stone crib structure often serve as summer habitat for the snake. Lake Erie Watersnakes typically forage for fish and amphibians in Lake Erie, and recent research indicates that more than 90 percent of their current diet is composed of the nonnative, invasive fish round goby (Neogobius melanostomus) (King et al. 2006b, p. 110). Jones et al. (2009, p. 441) report that the mean foraging distance from shore was 85 m (279 ft), and the average water depth of the foraging locations was 3.32 m (10.9 ft). During the summer, 75 percent of Lake Erie Watersnakes are found within 13 m (42.7 ft) of the water’s edge (King 2003, p. 4). King (2003, p. 4) identified that 75 percent of Lake Erie Watersnakes used 437 m (1433 ft) of shoreline or less as a home range. Individual snakes often demonstrate site fidelity, returning to the same shoreline area in successive years (King 2003, pp. 4, 11- 17).

 

In the winter, Lake Erie Watersnakes hibernate below the frost level, in cracks or crevices in the bedrock, interstitial spaces of rocky substrates, tree roots, building foundations, and other similar natural and human-made structures. Seventy-five percent of Lake Erie Watersnakes hibernate within 69 m (226 ft) of the water’s edge (King 2003, p. 4). Individual snakes often demonstrate site fidelity, returning to the same or nearby hibernacula in successive years (King 2003, pp. 4, 11-17).

 

Additional information on the Lake Erie Watersnake’s life history and biology can be found in the final listing rule (64 FR 47126, August 30, 1999), Lake Erie Watersnake Recovery Plan (Service 2003, pp. 6-11), and the proposed delisting rule (available at: http://www.fws.gov/endangered).

 

The Service classified the Distinct Population Segment of “Lake Erie water snakes” on the Offshore Islands of Western Lake Erie as a threatened species on August 30, 1999 (64 FR 47126). The subspecies was listed primarily due to the threat of intentional human persecution, but also due to habitat destruction and modification, small population size, and restricted range.

 

On September 25, 2003, the Service announced the availability of an approved recovery plan for the Lake Erie Watersnake (68 FR 55411). In the recovery plan (Service 2003, p. G-19) we describe a revision to the common name from “Lake Erie water snake” to “Lake Erie Watersnake” per the peer-reviewed naming convention outlined in “Scientific and Standard English Names of Amphibians and Reptiles of North America North of Mexico, with Comments Regarding Confidence in Our Understanding” (most recent version Crother 2008, p. 58). Subsequently, we refer to the subspecies as “Lake Erie Watersnake” in this and future documents.

 

Concurrent with this Post-delisting Monitoring Plan, we are removing the Lake Erie Watersnake from the List of Threatened and Endangered Wildlife due to recovery. The delisting rule is available at http://www.fws.gov/endangered or by calling our Ohio Ecological Services Office at 614-416-8993.

 

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Above are the Table of Contents, Introduction, and Background sections of the Plan. Download a PDF version of the complete 34-page Lake Erie Watersnake Post-Delisting Monitoring Plan.

 

 

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Last updated: January 3, 2013