Photo reportage - field science with amphibians in Rocha, Uruguay.
During the 3 years that I was a biology student at Science College in Montevideo, Uruguay (2013-2015) I had the opportunity to be a field assistant to a passionate biologist who was working on her Ph.D. thesis.
We made a total of 15 field trips of 3 to 4 days to Rocha, a state at the east coast of the country, searching a particular species of amphibian: the Melanophryniscus montevidensis aka "sapito de Darwin" ("Darwin's toad"). A smallness of no more than 3 cm, with wonderful coloration and in danger of extinction.
In addition to helping to collect information about them to promote their conservation, I was able to delve into the intriguing and mesmerizing world of amphibians, while also getting to know breathtaking landscapes of my country.
I invite you to read Cecilia's Ph.D. thesis, read one of the published scientific articles and this other one too.
So this is little cute Melanophryniscus montevidensis.
Here is a reference to their smallness, compare them to the size of the hands.
You can also see they have some yellow spots on their head, and red and yellow spots on their belly. This coloration is called "aposematic" because it indicates to possible predators that they are poisonous.
But there is still more about their skin, their spots and marks on their bellies have a unique pattern that makes them individually recognizable, like our fingerprints or our irises.
We held them with gloves because of the poisonous alkaloids they secrete, and because we also did swabs on their skin to analyze the presence of chytridiomycosis (a lethal disease that attacks their skin and keratinous structures, that's caused by an aquatic fungus).
These are some of the places they live.
They are very elusive and do not like photos, they prefer to dig their small caves and take shelter in them in winter, and walk around looking for food in summer.
They are rarely seen swimming, they only do it when they mate, and are able to do it with great grace. There is a popular anecdote about Darwin in Uruguay, apparently he found one of these funny little toads and put it in a small pond, but the poor man swam so badly that Darwin had to rescue him back to mainland.
They mate during the humid and rainy days of summer. The males sing in a very cute way to call the females and when they "match" the proceed to do the amplexus or "nuptial hug". They lay their very small eggs in water, attached to reeds or plants. After a week, totally black tadpoles emerge from there, and the metamorphose (the process in which they gradually transform into tiny terrestrial toads) takes from 20 to 30 days.
As they grow, they develop more and more their spots ands marks on their face, their limbs and their bellies. They keep growing, then they mate again and thus their life cycle continues in the pond.
If you want to learn more, you can read about the habits of Darwin's toad in this article from a Uruguayan newspaper.
Currently their populations have been disappearing due to urbanization and water pollution. In the same place where Darwin's toads live there are many other species of amphibians too. I invite you to meet them cause when we get to know, we get to appreciate, and when we appreciate we get to care.
This is the beautiful Hypsyboas pulchellus aka "climbing frog" or "thrush frog", and it's scientific name is really accurate as pulchellus is the latin word for "beautiful".
This is Dendropsophus sanborni or "Sanborn's dwarf frog", it's a tiny perfect fragile and elusive miniature frog.
This is the Leptodactylus latinasus or "piadora" frog (because of the sound the male makes when he sings). It's a very common frog throughout the country and is a specialist in camouflage.
This is a Scinax granulatus, or "snoring frog". It's very friendly and gets along well with humans, it's quite common to find it in house's bathrooms. Its coloration varies from silvery gray to golden brown, and it's always a very cute frog to watch and appreciate.
This is Mr. Rhinella fernandezae or "Fernández's garden toad". Despite having an angry or moody face he's very nice, and as his name says he usually gets well with humans and lives in house's gardens. In the second picture you can see their size when they come out of the water, they are barely bigger than a bunch of grains of sand.
Here we have friendly and smiling Pseudis minuta or "big buoying frog". They love water and are great swimmers. It's the only species in Uruguay, along the "small buoying frog", in which the male has 2 vocal sacs, since the rest have only 1. The funny thing about this frog's singing is that it sounds like a duck.
Here we have Leptodactylus latrans (leptodactylus means they have "long fingers") and they are commonly known as "common frog", but do not get carried away by their name, it's very interesting species.
In the photos above we can see a male specimen, they are very strong, muscular and robust.
In the photos below we can see a female, less physically strong but very determined when it comes to taking care of her tadpoles. This is the only species in our country that's known to have parental care, this means that when someone approaches their offspring they become really aggressive and jump or take "bites" to defend them (actually I was bitten once). But they also have their cute and funny side.
This is Scinax squalirostris, or big snout frog. It seems to me a very strange and cute little frog because it has the face of a fish and sings as if it was a little sheep.
Last but not least, we have Rhinella arenarum arenarum or "common toad". It lives along the entire Uruguayan coast in sandy soils, hence its scientific name ("sand" in Spanish is arena).
As you can see in the pictures, they really like to dig in the sand and shelter there.
In mating season, males develop hard structures on their hands called "nuptial calluses" that help them to hold the female during amplexus.
Of course I love to talk about amphibians and could do it for hours and hours, but that was it for today friends. I hope you liked it and learned a little more about these fascinating creatures.
If you read this far: thank you very much!
