A radio transmitter externally attached to an eastern massasauga rattlesnake. USWFS photo by M. Redmer.

Lincoln Park Zoo staff members Diane Mulkerin (left) and Dr. Robyn Barbiers (right)fill out a massasauga survey data form. USFWS photo by M. Redmer.

Cathy Pollack, from the Service's Chicago Illinois Field Office, uses radiotelemtry to find a previously captured eastern massasauga rattlesnake (visible, but hiding in grass lower right part of image). USFWS photo by M. Redmer.

An eastern massasauga rattlesnake with an externally attached radio trasnmitter. USFWS photo by M. Redmer.

For the third consecutive year, the Chicago Illinois Field Office has played a lead role in coordinating efforts of a team of stakeholders and interested partners to survey and monitor one of the last remaining populations of the eastern massasauga rattlesnake (Sistrurus c. catenatus) in northeast Illinois.  The massasauga is listed as endangered by the State of Illinois and is a candidate for federal listing as well.  Since 2000, confirmed records of the massasauga are available for only three location in this corner of the state, and only one of those has yielded at least one sighting in all but one year since then. 

Beginning in 2006, the Chicago Field Office assembled a small group of biologists from the Service, Illinois DNR, and several county agencies to assist with an effort to survey massasaugas and conduct a long-term mark-recapture study to assess the area's massasauga populations.  Participants were trained in a standardized survey and data collection protocol, as well as safe handling of the venomous EMR. 

Survey efforts concentrated on the period of spring egress, when the snakes leave their winter hibernacula (crayfish burrows), and before they disperse into surrounding grasslands.  In 2006 only 10 massasaugas were found (accounting for over (40 encounters), all at one historic location.  In 2007 only five individual massasaugas were found (accounting for seven encounters), and all but one were snakes first captured in 2006.  Surveys at four other historic sites were unsuccessful in both of the first two years.

Because of the extremely low numbers of eastern massasauga found in the first two years, the stakeholder/partner groups decided that additional measures needed to be considered to determine if additional snakes were going undetected during egress surveys, or if the numbers at the one site were reflecting a truly small, and potentially non-viable population.  Because male and female massasaugas may spend several days together during the summer mating season, radiotelemetry of snakes captured early in the year is one technique that can be used to follow snakes caught in spring in hopes of finding previously undetected snakes (e.g., when they pair up with a mate later in the year).  However, traditional radiotelemetry with snakes involves surgical implantation, and exposes individual snakes to a risk of infection or other complications.  Thus, in 2008, a number of small, external radio transmitters were ordered.  These radio transmitters are being attached to the snakes skin with a small dab of Super Glue Gel.  A trade-off with this approach is that  snakes can lose the transmitter when they shed their skin.  Because of this, they must be monitored closely and held for 3-5 days in captivity if a shed is impending.  After the snakes shed the transmitters are re-attached and the snake is released at the point where it was captured.  Snakes caught this spring will be tracked until early fall.  Any new snakes detected during the mating season could be be telemetered into the winter, thus opening the possibility of finding previously unknown hibernacula where future survey efforts could be directed.