Checking up on Translocated Tortoises
The Orianne Society will be kicking off a new radio telemetry study to determine the effects of translocation on Gopher Tortoises in southern Georgia. Translocation is the transport and release of plants, animals, or habitats from one location to the other — in this case, Gopher Tortoises. In August of 2011, The Orianne Society partnered with the Georgia Department of Natural Resources to translocate 32 Gopher Tortoise from private lands that were being converted to agriculture, to The Orianne Indigo Snake Preserve and Yuchi Wildlife Management Area to enhance current Gopher Tortoise populations at these sites. The tortoises were placed in one hectare pens at each site to overwinter and to promote site fidelity. Prior to translocation, each tortoise was tested for the Upper Respiratory Track Disease (URTD), a disorder caused by the bacteria Mycoplasma agassizii, which colonizes in the respiratory track and is contagious. None of the translocated tortoises tested positive for URTD.
Now, The Orianne Society and the Georgia Department of Natural Resources are teaming up again to study the effects of translocation on these tortoises. In June of 2012, prior to taking down the overwintering pens, we will trap each translocated tortoise, weigh and measure them, and fit them with a radio-transmitter. Radio-transmitters are glued to carapace of the tortoise and do not hinder concealment or cause harm to the individual tortoise. The transmitter setup weighs less than 1% of an adult tortoise's body weight.
Following the removal of the pen walls, the tortoises will be tracked once a week for the next four months and then bi-monthly from November 2012 to June 2013. When a transmittered tortoise is located a GPS coordinate of the spot of the location will be recorded, as will the habitat type the tortoises was utilizing. We will also weigh and measure each transmittered tortoise once a month.
Using the data collected from this field study, we can determine if translocated Gopher Tortoises reside in or disperse away from the translocation site and if home range size and habitat use of translocated tortoises differ from resident tortoises at each site. Also, monitoring the body condition of the translocated tortoises and comparing that to resident tortoises will allow us to determine if translocated tortoises can maintain a healthy body condition and whether there are survival consequences to translocating tortoises.
Translocating wildlife is not a new practice, but the importance of this study is significant. As of yet, we do not fully know or understand the effects of translocation on this species. There is concern regarding the spread of disease, mortality rates of translocated individuals, impacts to resident populations, and whether or not we should be focusing more on reducing the amount of habitat being destroyed than moving species to increasing less areas of suitable habitat. This study will help us better understand the implication of translocating Gopher Tortoise populations – something that unfortunately is becoming more common with the loss of their habitat.