Pattern Recognition – The Natural ID Mark

I have always felt that some of the traditional methods of marking anurans (frogs and toads) and lizards were outdated and unnecessary. They often involve clipping the toes and fingers in different combinations to give a unique code that allows for identification of individuals during a study.

While it can be argued that little of no consequence to the individual involved as you often find animals with missing digits (from fighting with other animals, depredation attempts and other factors) that seem to suffer no reduced ability to move, it just seems wrong for us as responsible scientists and people to be carrying out that act.

Surely if there are other less invasive methods that we can use (regardless of whether they take more time) then thats what we should go for. Thats where pattern recognition comes in. Anyone who has spent enough time in the field will start to recognise that patterns amongst individuals varies to some degree (in most cases).

We can use this for our studies, although going through 100’s sometimes 1000’s of photos is very time consuming.

We are always looking for the least invasive methods to use, and develop, during our expeditions and research projects.

Over the last few years with the advent of digital photography and advances in computer technology affordable options are starting to emerge. I am really excited to see if WildID can recognise the differences in back patterns between two sheep frogs (Hypopachus variolosus).

This new open source pattern recognition software developed by Douglas Bolger and colleagues at Dartmouth College, New Hampshire, will hopefully save us lots of time going through 100’s of photos of these little frogs. Very little is known about the ecology of sheep frogs and with luck we will be able to shed some light on what they get up to on the forest floor.


We will also be trialling this method on Morelet’s crocodiles (Crocodylus moreletii) during our Crocodile and River Turtle Project in June this year. Studies have shown that in some species the scalation around the neck of crocodiles varies enough to allow individual recognition. We will be marking Morelet’s crocodile to allow us to assess the population status of this rare species in the rivers around Las Guacamayas.

By combining this and pattern recognition of the scales we will be able to show if this hands off method is an accurate method for this species, and thus eliminate the need to catch animals. All we will need to do is get close enough to take the photos!!

Now there is a challenge!

Morelets crocodile -Crocodylus moreletii

Morelets crocodile -Crocodylus moreletii

Published : 15th April 2015

Field Notes Archive

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