Barking Marsh Frog or Spotted Marsh Frog?

[PythonOwner25]

Hey all, Was up around Echuca over the Easter long weekend searching for Barking Marsh Frogs (Limnodynastes fletcheri). I had no luck in hearing fletcheri calling, but did find large amounts of Spotted Marsh Frogs which seem to look fairly similar to Barking Marsh Frogs. I searched for a few nights and still nothing, only to uncover this fella under my tent on Sunday morning. It has largish red patches behind its eye (not clearly visible in photo) and seemed a different colour and slightly different in shape to most of the spotted marsh frogs i'd seen. Thats what sparked me to it being a fletcheri. I hope it is!


Barking Marsh Frog? (Limnodynastes fletcheri) by Matt Clancy Wildlife Photography, on Flickr

Any help appreciated.

Cheers,

Matt.

 

[Bushman]

As you probably know Matt, the call is the most reliable method of identifying Limnodynastes fletcheri from L. tasmaniensis, which it resembles and is most often confused with.
However, having said that there are a few features that can be used to distinguish between the two species.
Firstly, I think that the most distinctive feature is the butterfly-shaped blotch between the eyes that L. fletcheri usually has, that is typically absent in L. tasmaniensis. Although I can't see the butterfly shape from that oblique angle, it looks vaguely like it is present on that specimen.
Another distinguishing characteristic between the two species is that the spots and blotches on the back of L. tasmaniensis tend to be regularly shaped, with smooth borders while those of L. fletcheri tend to be irregularly shaped with obscure and fuzzy edges and are often interspersed with dark flecks and peppering.
Also, as you mention L. fletcheri often has a small, red or orange patch on the upper eyelid but this is extremely rare in L. tasmaniensis. I can just make out a bit of warm orange pigment above and behind the eye, which approximates the upper eyelid region. Is this where you saw it in the flesh?
Most L. tasmaniensis that I have seen have green coloured dorsal blotches, whereas this specimen has brown blotches which I've seen on L. fletcheri before.
So I think that you may have found yourself a Limnodynastes fletcheri.

 

[PythonOwner25]

As you probably know Matt, the call is the most reliable method of identifying Limnodynastes fletcheri from L. tasmaniensis, which it resembles and is most often confused with.
However, having said that there are a few features that can be used to distinguish between the two species.
Firstly, I think that the most distinctive feature is the butterfly-shaped blotch between the eyes that L. fletcheri usually has, that is typically absent in L. tasmaniensis. Although I can't see the butterfly shape from that oblique angle, it looks vaguely like it is present on that specimen.
Another distinguishing characteristic between the two species is that the spots and blotches on the back of L. tasmaniensis tend to be regularly shaped, with smooth borders while those of L. fletcheri tend to be irregularly shaped with obscure and fuzzy edges and are often interspersed with dark flecks and peppering.
Also, as you mention L. fletcheri often has a small, red or orange patch on the upper eyelid but this is extremely rare in L. tasmaniensis. I can just make out a bit of warm orange pigment above and behind the eye, which approximates the upper eyelid region. Is this where you saw it in the flesh?
Most L. tasmaniensis that I have seen have green coloured dorsal blotches, whereas this specimen has brown blotches which I've seen on L. fletcheri before.
So I think that you may have found yourself a Limnodynastes fletcheri.

Thanks Heaps Bushman! It did look slightly different to all the tasmaniensis that I've ever seen, and the red eye blotches are what struck me as L.fletcheri. click on the picture link below, Its a top shot showing the red behind eyes.
.

View attachment 287531

 

[Bushman]

My pleasure Matt. Happy to help.
It's a good photo and it really helps ID's to work with a good quality high resolution version that this image is linked to.
By the way, the link in your reply doesn't seem to work. Can you try again?

 

[eipper]

It looks like a northern call race tassie to me

 

[jedi_339]

Hey bushman,

I was under the impression that either species can have any of the markings you've used as characteristics to distinguish the two.

I have a bit of info from someone who did a phd on the two species and she used these characters as the only way other then call.

Lim tas
Metacarpal tubercles all about the same length
Webbing on feet joins just below first knuckle (may only just do so)
May have one OR two metatarsal tubercles

Lim fletch
One metacarpal tubercal much longer then the others,
Webbing on feet joins just above first knuckle (may only just do so)
Have only one metatarsal tubercle.

Hope that helps

 

[jedi_339]

Apologies my enter button seems to have not worked :/

 

[richoman_3]

im going with tasmaniensis.....

 

[Bluetongue1]

Good info Jedi. I steered clear of this one. I have had nothing to do with L. fletcheri but have seen a lot of L. tasmaniensis, albeit from a somewhat restricted distribution, and they are just so variable in pattern and colour that they could fit either description given. The "Frogs of Queensland" website has a picture of three L. tasmaniensis showing some of that varition in markings, including red patches on the back of the eyelids.

Does any one know if L. fletcheri have a consistently longer thumb and is that a possible diagnostic feature that could also be used?

 

[GeckPhotographer]

Does any one know if L. fletcheri have a consistently longer thumb and is that a possible diagnostic feature that could also be used?

The information I've been given is that that is the morphological key feature separating them.

 

[jedi_339]

I'd like to know how a male of either species distinguishes their females if both species are calling from nearby locations. Food for thought?

 

[eipper]

Most likely pheromones.

 

[Bluetongue1]

Thanks for that confirmation Geckphotographer. Much appreciated.

Blue