FWS Focus

Overview

Characteristics
Overview

The eastern massasauga rattlesnake is a small pit viper that occurs in the northern midwest United States and Ontario, Canada. Originally believed to be a subspecies of western massasauga rattlesnake, genetic analyses have since demonstrated it to be a distinct species that was reclassified in 2011 as Sistrurus catenatus.

Eastern massasaugas were listed as threatened under the Endangered Species Act in 2016 due to significant reductions in populations primarily due to habitat loss. The historical range of the species included New York, western Pennsylvania, southeastern Ontario, Michigan, Ohio, Indiana, Illinois, Wisconsin, Minnesota, east central Missouri and eastern Iowa.

Scientific Name

Sistrurus catenatus
Common Name
Massasauga
Eastern Massasauga
Eastern Massasauga (=rattlesnake)
FWS Category
Reptiles
Kingdom

Location in Taxonomic Tree

Identification Numbers

TSN:

Characteristics

Characteristic category

Physical Characteristics

Characteristics
Color & Pattern

These snakes are most often gray or light brown, but can be black, with large light-edged chocolate brown to black blotches on the back and smaller blotches on the sides. Their cryptic coloration allows them to rely on its camouflage to avoid predators and capture prey.

Size & Shape

Eastern massasaugas are thick-bodied, with a triangular-shaped head and vertical pupils. The most distinguishing feature of eastern massasauga rattlesnakes is a keratinized rattle at the end of the tail, which is used to ward off potential threats.

Characteristic category

Food

Characteristics
Food

These snakes eat small rodents like mice and voles, but will sometimes eat frogs and other snakes.

Characteristic category

Behavior

Characteristics
Behavior

This species is venomous, but because of the snakeโ€™s elusive and shy behavior, people rarely are bitten by them.

Characteristic category

Habitat

Characteristics
Habitat

Eastern massasaugas use shallow wetlands and surrounding upland areas to forage, breed, shelter and hibernate.

Geography

Characteristics
Range

Currently, most of the remaining populations are concentrated in the center of the range, with the strongholds being in Michigan and Ontario, Canada. New York, Pennsylvania, Ohio, Indiana, Illinois, Wisconsin and Iowa still have some robust populations, but they become fewer in number and increase in geographic isolation towards the edges of the species range.

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Timeline

Explore the information available for this taxon's timeline. You can select an event on the timeline to view more information, or cycle through the content available in the carousel below.

28 Items

Listing

Listing

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Critical Habitat

Five Year Review

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Listing

Dec 30, 1982

Dec 30, 1982 Listing
Review of Vertebrate Wildlife for Listing as End. or Thr. Species
  • Publication type: CNOR
  • Population:
Item 1

Listing

Oct 25, 1999

Oct 25, 1999 Listing
Review of Plant and Animal Taxa That Are Candidates or Proposed for Listing as Endangered or Threateโ€ฆ
  • Publication type: CNOR
  • Population:
Item 2

Listing

Oct 30, 2001

Oct 30, 2001 Listing
ETWP; Review of Plant and Animal Species That Are Candidates or Proposed for Listing as Endangered oโ€ฆ
  • Publication type: CNOR
  • Population:
Item 3

Listing

Jun 13, 2002

Jun 13, 2002 Listing
Endangered and Threatened Wildlife and Plants; Review of Species That Are Candidates or Proposed forโ€ฆ
  • Publication type: CNOR
  • Population:
Item 4

Listing

May 4, 2004

May 4, 2004 Listing
Review of Species That Are Candidates or Proposed for Listing as Endangered or Threatened; Annual Noโ€ฆ
  • Publication type: CNOR
  • Population:
Item 5

Listing

May 11, 2005

May 11, 2005 Listing
Endangered and Threatened Wildlife and Plants; Review of Native Species That Are Candidates or Proโ€ฆ
  • Publication type: CNOR
  • Population:
Item 6

Listing

Sep 12, 2006

Sep 12, 2006 Listing
Review of Native Species That Are Candidates or Proposed for Listing as Endangered or Threatened; Anโ€ฆ
  • Publication type: CNOR
  • Population:
Item 7

Listing

Sep 12, 2006

Sep 12, 2006 Listing (Warranted But Precluded: Resubmitted)
Review of Native Species That Are Candidates or Proposed for Listing as Endangered or Threatened; Anโ€ฆ
  • Publication type: 12m petition finding
  • Population:
Item 8

Listing

Dec 6, 2007

Dec 6, 2007 Listing
Review of Native Species That Are Candidates for Listing as Endangered or Threatened; Annual Noticโ€ฆ
  • Publication type: CNOR
  • Population:
Item 9

Listing

Dec 6, 2007

Dec 6, 2007 Listing (Warranted But Precluded: Resubmitted)
Review of Native Species That Are Candidates for Listing as Endangered or Threatened; Annual Noticโ€ฆ
  • Publication type: 12m petition finding
  • Population:
Item 10

Listing

Dec 10, 2008

Dec 10, 2008 Listing
Review of Native Species That Are Candidates for Listing as Endangered or Threatened; Annual Noticโ€ฆ
  • Publication type: CNOR
  • Population:
Item 11

Listing

Dec 10, 2008

Dec 10, 2008 Listing (Warranted But Precluded: Resubmitted)
Review of Native Species That Are Candidates for Listing as Endangered or Threatened; Annual Noticโ€ฆ
  • Publication type: 12m petition finding
  • Population:
Item 12

Listing

Nov 9, 2009

Nov 9, 2009 Listing (Warranted But Precluded: Resubmitted)
Review of Native Species That Are Candidates for Listing as Endangered or Threatened; Annual Noticeโ€ฆ
  • Publication type: 12m petition finding
  • Population:
Item 13

Listing

Nov 9, 2009

Nov 9, 2009 Listing
Review of Native Species That Are Candidates for Listing as Endangered or Threatened; Annual Noticeโ€ฆ
  • Publication type: CNOR
  • Population:
Item 14

Listing

Nov 10, 2010

Nov 10, 2010 Listing (Warranted But Precluded: Resubmitted)
Review of Native Species That Are Candidates for Listing as Endangered or Threatened; Annual Noticeโ€ฆ
  • Publication type: 12m petition finding
  • Population:
Item 15

Listing

Nov 10, 2010

Nov 10, 2010 Listing
Review of Native Species That Are Candidates for Listing as Endangered or Threatened; Annual Noticeโ€ฆ
  • Publication type: CNOR
  • Population:
Item 16

Listing

Oct 26, 2011

Oct 26, 2011 Listing (Warranted But Precluded: Resubmitted)
Review of Native Species That Are Candidates for Listing as Endangered or Threatened; Annual Noticeโ€ฆ
  • Publication type: 12m petition finding
  • Population:
Item 17

Listing

Oct 26, 2011

Oct 26, 2011 Listing
Review of Native Species That Are Candidates for Listing as Endangered or Threatened; Annual Noticeโ€ฆ
  • Publication type: CNOR
  • Population:
Item 18

Listing

Nov 21, 2012

Nov 21, 2012 Listing (Warranted But Precluded: Resubmitted)
Review of Native Species That Are Candidates for Listing as Endangered or Threatened; Annual Noticeโ€ฆ
  • Publication type: 12m petition finding
  • Population:
Item 19

Listing

Nov 21, 2012

Nov 21, 2012 Listing
Review of Native Species That Are Candidates for Listing as Endangered or Threatened; Annual Noticeโ€ฆ
  • Publication type: CNOR
  • Population:
Item 20

Listing

Nov 22, 2013

Nov 22, 2013 Listing (Warranted But Precluded: Resubmitted)
Review of Native Species That are Candidates for Listing as Endangered or Threatened; Annual Noticeโ€ฆ
  • Publication type: 12m petition finding
  • Population:
Item 21

Listing

Nov 22, 2013

Nov 22, 2013 Listing
Review of Native Species That are Candidates for Listing as Endangered or Threatened; Annual Noticeโ€ฆ
  • Publication type: CNOR
  • Population:
Item 22

Listing

Dec 5, 2014

Dec 5, 2014 Listing (Warranted But Precluded: Resubmitted)
Review of Native Species That Are Candidates for Listing as Endangered or Threatened; Annual Noticeโ€ฆ
  • Publication type: 12m petition finding
  • Population:
Item 23

Listing

Dec 5, 2014

Dec 5, 2014 Listing
Review of Native Species That Are Candidates for Listing as Endangered or Threatened; Annual Noticeโ€ฆ
  • Publication type: CNOR
  • Population:
Item 24

Listing

Sep 30, 2015

Sep 30, 2015 Listing (Threatened)
Threatened Species Status for the Eastern Massasauga Rattlesnake; Proposed rule
  • Publication type: Proposed
  • Population:
Item 25

Listing

Sep 30, 2016

Sep 30, 2016 Listing (Threatened)
Endangered and Threatened Wildlife and Plants; Threatened Species Status for the Eastern Massasaugโ€ฆ
  • Publication type: Final
  • Population:
Item 26

Critical Habitat

Sep 30, 2016

Sep 30, 2016 Critical Habitat (Not prudent at final listing)
Endangered and Threatened Wildlife and Plants; Threatened Species Status for the Eastern Massasaugโ€ฆ
  • Publication type: CH Prudency Determination
  • Population:
Item 27

Five Year Review

Aug 31, 2020

Aug 31, 2020 Five Year Review (Information Solicitation)
Initiation of 5-Year Status Reviews of 14 Listed Animal and Plant Species
  • Publication type: Notice
  • Population:
Item 28