Thermal Imaging & Its Potential Impact On Wildlife Management

In the summer of 2006 the Agency began utilizing a relatively new and exciting technology that may have vast ramifications in the world of wildlife management. TWRA biologists recently began "experimenting" with a thermal imager and are just now developing protocols to collect more accurate and more detailed information about our wildlife populations.


What Is A Thermal Imager?

Thermal image of a man running down a streetA thermal imager is more-or-less a "night-time" video camera. However, instead of amplifying ambient light like night vision goggles, it records and sees heat. If you have ever watched "Cops" you have seen this technology. The guy running down the street that is glowing white...that is a thermal image. Take a look at the below image if you are not sure what we're talking about.


Instead of seeing a specific temperature, the camera sees temperature differences. The man running down the street is approximately 98 degrees Fahrenheit, unfortunately roads and buildings sometimes retain heat approaching that temperature. For example if the men above were standing in front of the warm vehicle to the right, you may not detect them. If on the other hand, you place that man in the middle of a bean field, which has cooled to night-time temperatures, there is absolutely no way for that man to blend in. More or less he is the only thing glowing in a field of black.


The TWRA Experiments With Thermal Imaging

The Agency conducted a pilot project in Middle Tennessee which utilizes the thermal imager to determine buck/doe ratios and fawn/doe ratios on a countywide scale.

Over the course of three nights biologists thoroughly covered a Middle Tennessee county and in just over eight hours of observation time, we recorded 289 deer observations. Of the observations, 215 were confirmed observations in which the deer were placed into three distinct categories: adult buck, adult doe, and fawn.

The results are: 68 Adult Bucks, 101 Adult Does, 46 Fawns, (74 Unknowns)

This would equate to a countywide buck-to-doe ratio of 1 to 1.48. This is probably an accurate representation of most counties in this particular vicinity. There is no doubt there are some areas that will be slightly better and some areas that will be slightly worse. However, it is a far cry from the 4:1 or 6:1 ratios that many hunters often report.

The fawn-to-doe ratio for the county was 1 to 0.45, however we feel this is slightly below actual since fawns are often left unattended and not always sighted with the doe. This shows the imager's limitation in getting precise fawn recruitment, however, it is an excellent tool in getting "minimal recruitment rates".

As a result of the experiment, most counties in TN appear to be in great shape. The Agency will continue to utilize these new technologies to manage our wildlife populations to our utmost capabilities.