Conserving the Eastern Massasauga Rattlesnake: Field Notes from a Herpetologist

The Oklahoma City Zoo and Botanical Garden recently welcomed three Eastern massasauga rattlesnake snakelets, a federally protected species, to its Herpetarium habitat for the first time in its history as a result of a successful breeding effort this past May. The Association of Zoos and Aquarium’s (AZA) Eastern Massasauga Rattlesnake Species Survival PlanTM (EMR SSP) is comprised of 19 AZA-accredited zoos, including the OKC Zoo. As part of the Zoo’s commitment to the EMR SSP, Zoo Herpetologist, Rae Karpinski, was sent to the annual EMR SSP meeting in Cassapolis, Michigan. Here are Rae's notes from the field:

As a born and raised Michigander, the Eastern massasauga rattlesnake, Michigan’s only venomous snake, is near and dear to my heart. I even have a tattoo of one on my forearm! Eastern massasauga rattlesnakes’ native habitat extends from central New York and southern Ontario west to the prairies of Iowa and Missouri. Here in Oklahoma, Eastern massasauga rattlesnakes are not native, however, Western massasauga rattlesnakes are. Eastern massasauga rattlesnake populations are threatened by habitat loss due to human encroachment.

Eastern massasauga rattlesnakes are venomous, so to handle venomous snakes safely, a variety of tools are utilized. Snakes hooks, or snake tongs, are used to pick up and transport snakes into a secured container when needed. At the Zoo, herpetologists do not share space with venomous animals for our safety and that of the animals in our care. As an extra safety precaution, the Zoo houses antivenom for every species of snake in its animal family and caretakers receive extensive venomous handling training prior to caring for any venomous animals.

This May, I traveled back to my home state of Michigan to conduct field research as part of my involvement in the EMR SSP program at the Edward Lowe Foundation. Locating these snakes in the wild can be challenging because of their shy behavior and cryptic coloration, as well as the wetlands and marshes they inhabit. Field research is crucial to the study of this species and provides helpful data to research biologists. The particular study in which the SSP participates is an ongoing study from 2009 collecting genetic and demographic data, which are used for population modeling. When conducting field research, rattlesnakes are located and checked for the presence of a PIT tag, which indicates if they’d been studied in previous years. They are also sexed, weighed, measured and blood samples are collected. Before each rattlesnake is handled, researchers collect environmental data such as wind speed, ground temperature, GPS waypoints and humidity. Once studied, the rattlesnakes are re-released back into the wild where they were initially located.

This past year at the EMR SSP meeting, 34 rattlesnakes were located, and I was deemed as the top snake finder after locating six individual snakes. During the SSP meeting, it is determined which Eastern massasauga rattlesnakes in human care at AZA organizations are recommended to breed with one another to bolster their population. The OKC Zoo is home to three adult Eastern massasauga rattlesnakes, two males and one female. One pair was matched as a breeding recommendation from the EMR SSP.

The Zoo introduced the breeding pair to each other after a three-month cooling period in the Zoo’s hibernaculum, which simulates winter hibernation the snakes would experience in the wild. The pair successfully bred once introduced. Rattlesnakes are ovoviviparous. This means they give birth to live young after developing and retaining the eggs inside their bodies. Our reptile care team worked with the Zoo’s veterinary team to provide ultrasounds every two weeks to monitor the development of the snakelets. On May 31, 2021, three snakelets were born. This birth marks the first time the Zoo has successfully bred Eastern massasauga rattlesnakes.

In the wild, the snakelets remain with their mother for the first several days after birth until they complete their first shed after which they disperse to find food. Eastern massasauga rattlesnake snakelets reach sexual maturity between three and four years old of age. The Zoo’s rattlesnakelets are healthy and eating well. The snakelets have been placed in individual habitats so that caretakers can monitor food intake, weight and development.

As a passionate herpetologist, caring for the first rhumba of rattlesnakelets (group of rattlesnakes) to be born in the Zoo’s history, has been a career highlight. From pairing the adult rattlesnakes together and monitoring the pregnancy through ultrasounds, to caring for the newborn snakelets and watching them grow, it’s been exciting to be a part of this endeavor. I’m proud to have a role in conserving this unique rattlesnake species at the OKC Zoo.

The adult Eastern massasauga rattlesnakes are currently off public view in the Herpetarium, as the habitat undergoes renovation. One juvenile is viewable to guests at the Herpetarium, while the other two juveniles remain off public view.


- Rae Karpinski, lead herpetologist and Eastern Massasauga Rattlesnake SSP program institutional representative


Posted by Sabrina Heise at 09:10
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