Names, numbers, stickers -whatever, they all do the keeping track thing and it can be important especially when it comes time to get your paycheck or medicine.  The same holds true when your working with animals -determining who’s who is sometimes very critical information.  It’s not so hard you think… ever seen a cow with an ear tag?…  But what if the animal you’re working with weighs 6 grams? or 2 grams?  What if it’s federally endangered and you want to be especially sure that the animal’s behavior or health is not affected?  These are questions researchers face all the time and a new way to keep track of individuals can be a huge step forward.

How do you keep track of 2 gram slimy little salamanders?  Well you can give them florescent tattoos.  No really, I’ve given hundreds the little marks.  Just mix up a little bit of elastomer and inject it just under the skin with insulin syringes… Oh, and make sure you get the right color in the right place.  It’s definitely an art.

This is number 229… just after injection (sitting on a piece of Plexiglas).  The marks are permanent and they have no effect on growth or reproduction (Bailey 2004).  They also fluoresce under UV light -the tiniest mark glows brightly if you shine a portable UV light on it.

What about the bats? They get a tiny arm band.  The band is engraved with numbers and letters and fits loosely on the arm allowing for growth and movement.

The above picture shows the band size for Indiana and other small bats.

If you ever find dead animal with a tag or mark of some kind report it to your local Fish and Wildlife department.  The information may be very useful to someone who’s trying to keep track.

Bailey, L. L. 2004. Evaluating elastomer marking and photo identification methods for terrestrial salamanders: marking effects and observer bias. Herpetological Review 35:38-41.

Take for example this frog I found escaping from the sun’s hot rays beneath some flowerpots on our deck. Hopefully all of you will be able to be able to agree that it is indeed a frog. Perhaps quite a few of you will note that it is a treefrog by the large “sticky” toe pads just barely visible in the picture above. Hopefully there will be at least a few of you who will recognize it right away as being a gray treefrog; a common frog found throughout the eastern US and well known for breeding in everyone’s swimming pools (which, unfortunately for it, is not to its advantage). While you would be right in saying it’s a gray treefrog, you may be surprised that I still don’t know what species this frog is. The problem is there are actually two (externally) identical species of “gray treefrogs,” Cope’s Gray Treefrog (Hyla chrysoscelis) and Common Gray Treefrog (Hyla versicolor). Their ranges largely overlap and they can only be identified by their breeding call or DNA analysis (the Common Gray has twice as many chromosomes as Cope’s). Thus, this guy is one or the other but nobody can tell just by looking.

I think you are probably getting the picture -but wait it gets worse. I can remember during my undergraduate studies working at a stream with a local expert on fish identification. Our class was catching all sorts of different fish and then working to learn their proper identification. It is much harder than you might think to properly identify some of the species but I was catching on -or so I thought. One particular fish had me stumped so I asked the expert for some help and he told me seemingly without thinking “Oh, it’s just a hybrid” [yes it's true, some native species naturally hybridize].

Moral of the story: If a biologist tells you they don’t know what something is, don’t just assume they’re a pathetic excuse for a biologist. They may just be more honest than most.

Frog: Nikon D1x, Nikkor 70-300 f:4-5.6 ED