Frog Blog: Panamanian Granular ToadRhinella centralis

The Panamanian Granular Toad (Rhinella centralis) is a small flat-headed toad restricted to Panama. It used to be considered the same species with the widespread South American Granular Toad (R. granulosus) but it was elevated to its own species in 2009.

Range map from iNaturalist.org (2024)

When I read about these toads and saw pictures of them, for some reason I thought they would be medium to large sized toads since many Rhinella species are very large. I was rather surprised when I found these toads along a dirt road through the Tocumen Marshes in Central Panama just how small they were.

As you would expect for a toad of this size, it's call is a high pitched trill lasting around 3-4 seconds and with a carrier frequency (dominant pitch) of around 2.5kHz. In general pitch, it reminded me of the call of the North American Red-spotted Toad (Anaxyrus punctatus), although that species has a longer trill.

Here's a couple of Panamanian Granular Toads calling next to each other in the Tocumen Marshes -

Panamanian Granular Toads calling

As so often happens when you are trying to record one species of frog, another species right next to it pipes in and makes it hard to get the recording of your target species. That's what happened in this recording. I was trying to record a Colombian Four-eyed Frog (Pleurodema brachyops - the hollow "ponk, ponk") when a couple of Panamanian Granular Toads started calling right next to them, and then a Tungara Frog (Engystomops pustulosus) added its "toy ray gun" "PEUW" song to ruin my recording.

Panamanian Granular Toad with its neighbors