In Tobago, a Male Glass Frog Guards Its Eggs - Observation of the Week, 8/24/20

Our Observation of the Week is this Eastern Glass Frog, seen in Trinidad & Tobago by @zakwildlife!

Last week, after posting the above photo as our Observation of the Day, I saw that it was shared 75 times on Facebook, a significantly higher number than usual, even for a great photo like Zak’s. Scrolling through the shares, there were so many supportive comments from local nature groups, like this:

It was really great to get a glimpse into the naturalist community in the country, so I reached out to Zak get the story behind his observation. 

All of seventeen years of age now, Zak Ali says he first became involved in wildlife conservation at age eight, and credits his family camping trips into the primary forests of Trinidad for sparking his interest in nature, as well as wildlife books and Steve Irwin’s documentaries. He began by “training raptors that can't be released to become educational ambassadors.

I first started as an avid birder (mostly raptors) but currently at the age of seventeen, I have interests in everything from Reptiles, amphibians, birds and mammals. Other than the scientific aspect, I also love the wildlife photography aspect of it. My passion for wildlife drives me to protect and conserve, to learn and understand.

Zak and some of his colleagues recently traveled to Trinidad’s sister island, Tobago, which has endemic reptile and amphibian species. After sailing over, they journeyed to the Main Ridge Reserve to explore. 

The first night we encountered a crab-eating raccoon hunting on a river bank, unbothered by our presence, [and] I saw the glass frogs that night (Hyalinobatrachium orientale) and took a few images but wasn't pleased with them. The next night, with no reptiles in sight, I searched for the glass frogs and I noticed this glass frog sitting on a clutch of eggs, I had to photograph it!! (from my observation on site, the most mature set of eggs was guarded the best). The father guards the eggs from wasps, snakes and other predators, occasionally kicking off wasps that land on eggs. This was my second encounter with the Tobago glass frog, one I will not forget.

Eastern glass frogs are found on Tobago and parts of eastern Venezuela, and belong to the family Centrolenidae. Glass frogs get their name from the skin on their abdomen (ventral side) and legs, which is translucent in some species, making their internal organs visible. Mainly arboreal, these frogs lay clutches of eggs on the undersides of leaves overhanging streams. When the tadpoles are ready (or when disturbed) they’ll leave their eggs and drop into the water below. It is believed male eastern glass frogs cover egg clutches to not only protect them from predators, but to prevent fungal growth, infection, and desiccation.

Zak (above) says he uses iNat to record this observations and to scout out biodiversity and geographic distribution in an area. He and other naturalists also used iNat to record findings for last year’s Tabaquite Bioblitz, and Zak is also a co-founder of West Indian Herping, a group dedicated to educating people about reptiles, amphibians, and other wildlife of the region. “For a small twin island nation,” he says, “Trinidad and Tobago has a lot to offer, it has a very wide array of biodiversity...iNaturalist has made it easier to get locals interested in recording observations and getting involved.”

- iNat user @raindernd’s observation of a Stygian Owl back in 2018 was a first for Trinidad and Tobago! Check out the article here and a great video from Chaguanas Public Library about it here.

- @ldempewolf’s observation of a Microceris dulcinea butterfly also represents a first for this species in Trinidad and Tobago! Paper here

Posted by tiwane tiwane, August 24, 2020 21:24


Totally amazing! Thanks so much Zak, for bringing this gorgeous animal and fabulous photo to our attention!

Posted by susanhewitt about 1 year ago (Flag)

super photo/image and an amazing observation!

Posted by seaheart88 about 1 year ago (Flag)

I especially like photos that show a species in the context of their natural history. What a great photo! (I happen to live amphibians, too.)

Posted by vernal3 about 1 year ago (Flag)

Awesome! I did not know that the males guarded the eggs.

Posted by tothemax about 1 year ago (Flag)

Glad to hear about young naturalists trying to help out in their community.

Posted by chrisleearm about 1 year ago (Flag)

The kids are okay. I love this.

Posted by kitty12 about 1 year ago (Flag)

Lovely Kermit!! Well done @zakwildlife

Posted by sunnetchan about 1 year ago (Flag)

What a lovely capture! Congrats, Zak and thanks for sharing on iNaturalist! Amphibian-lovers like me all over the world are happier now!

Posted by sonnekke about 1 year ago (Flag)

Made my day!!!!!!!!!!!!

Posted by wildreturn about 1 year ago (Flag)

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