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Hello!

When I was grading my 2014 photos, I noticed that a juvenile Rana I had perceived as dalmatina had a Tympanum which was in fact too small for dalmatina. Common frog and agile frog occur syntopically at the location. The colouration and the snout's shape really make me doubt if I'm able to exclude R. temporaria - for all adult specimens I found that day were clearly R. dalmatina.
Is there an exception of the 'Tympanum-rule' for juvenile agile frogs or does this common frog one just look a bit 'agile'?

The snout shape and the distance between eardrum and eye vs. diametre of eardrum show this to be dalmatina. Or at least that's what I say

Thanks! I was confused especially by the quite small diameter of the ear-drum compared to the eye diameter which resembled Rana temporaria to me. The adult specimens had all eardrums as large as their eyes. So do the eye-eardrum-proportions differ between adults and juvenes?

Looking at the snout I'd say dalmatina too, but I'm not 100% convinced...

Mario Harzheim wrote: So do the eye-eardrum-proportions differ between adults and juvenes?

I would say so...

Do you have any other photos where one can see the proportion between leg length and body, or maybe the skin texture on the back?

I'm with Jeroen. Snout says dalmatina, colours, build, and just overall jizz, though inconclusive, support it. Though the eardrum is smallish I wouldn't really hesitate to call it agile.

Ilian Velikov wrote:the proportion between leg length and body

Imho, that's also a dangerous one with youngsters.

Jeroen Speybroeck wrote:Imho, that's also a dangerous one with youngsters.

True...I just thought this one is old enough to show the overall built of either dalmatina or temporaria.

Dear brownfroglovers,
there is one further characteristic - the iris coloration (see Dubois 1984).
The upper part of the Iris in dalmatina is golden the lower part is often brownish, and in between the upper and the lower part there are you there is a wedge of black.
Every adult brown frog with this characteristic I have found since 1997 I would call dalmatina.
However, some dalmatinas (in my eyes) missed this characteristic.
Sincerely
Alex

Ilian Velikov wrote:Do you have any other photos where one can see the proportion between leg length and body, or maybe the skin texture on the back?

Sorry, when I took the photo, I was quite sure it was dalmatina - until the point when the Typanum/ear-drum alienated me. So I took just a few photos that were supposed to look nice.

Ilian Velikov wrote:True...I just thought this one is old enough to show the overall built of either dalmatina or temporaria.

Maybe it looks a bit older than it was. From my memory, I would put the length to 2 cm.

Alexander Pieh wrote:Dear brownfroglovers,
there is one further characteristic - the iris coloration (see Dubois 1984).
The upper part of the Iris in dalmatina is golden the lower part is often brownish, and in between the upper and the lower part there are you there is a wedge of black.

Great tip! Didn't know that characteristic - but it also fits my other agile frog and common frog pictures of 2014.

A specimen from Northrhine-Westphalia whose lower iris part is quite light: