LeeValley once again has a precision pocket scale available for the low price of $14.95 in Canada: Precision Pocket Scale - Lee Valley Tools (it's available in the States as well), so I picked one up to monitor my frogs weight. Outside of LeeValley, they are mostly available from your local drug dealer supplier, and I like LeeValley so I went with them.

You can zero the scale with a (small) container on it then put the frog in the container and voila. It comes with a little pan you can use as well, and I'll probably use this most of the time but it has a sticker with instructions on it that will probably have to be removed (it will get wrecked from frequent cleanings in between frog weigh-ins anyway). I wouldn't weigh directly on the scale as it would be harder to make sure the frog is entirely on the pad and I wouldn't want to have to clean the scale with liquids any more than necessary. This scale is supposed to be accurate to within 1/10 of a gram for stuff under 20g, so I figure this is accurate enough for long term monitoring.

The scale in action on Waldo using the supplied pan:



Over the past few days I've weighed each of my frogs, this obviously requires taking them out of their cage so I waited to time it with cage cleanings or external feedings. For reference here are my results of weight, plus snout to vent length as best as I could determine it (frog on glass on a ruler):

Hyla versicolor
Waldo, 15.4g, 2 1/4"
Fatty, 15.6g, 2 1/4"
Try, 4.6g, 1 1/2"

Hyla cinerea
Bamf, 9.2g, 1 7/8"

Tyr might seem woefully underweight compared to the other two grays, but if all things scaled equally a 50% increase in one linear dimension means a 237.5% increase in volume (1.5x1.5x1.5=3.375). In other words, he'd be 15.525g if you added 50% to each linear dimension and things scaled this way up to 2 1/4". They all look about 'right' for weight, except I think Fatty could still stand to gain some weight (she lost a bunch after a prolapse in the summer). Bamf may also be slightly porky (H. cinerea are a little slenderer). I imagine the weight can vary a fair bit depending on the amount of water and food they happen to be carrying at the time so it's mostly long term trends I'm looking at monitoring, just like I do with my fat self on the bathroom scale.

If anyone has weighed their treefrogs, H. versicolor, H. cinerea or otherwise, I'd be interested to know the results for comparison purposes.