Reflective Tree Frogs

Adult R.exechopygus

Adult Rhacophorus exechopygus

As mentioned by Chris in his previous posts, one of the interesting adaptations we have been investigating is the ability for some amphibians to reflect light in the infrared spectrum. This may have multiple benefits; one to aid in camouflage, as this increases their ability to match the leaves that they sit on when resting, and a second to perhaps aid in thermoregulation. The reflectance has mostly been described in Central and South American species, such as the leaf frogs that we work with in The Vivarium.


This ability has also been observed in unrelated species of amphibians from other parts of the world that also live in a similar way to leaf frogs and is a great example of convergent evolution; how unrelated species have evolved similar adaptations as they live within a similar environment.


Young Rhacophorus exechopygus

One species that Chris and I are currently working with in the vivarium is the Tramlap Flying Frog, Rhacophorus exechopygus, from Vietnam and Laos. These are also a leaf sitting tree frog, much like their Central American counterparts we are used to working with in the Museum. Despite being completely unrelated to Phyllomedusine Leaf frogs we have found they also have the same ability to reflect infrared light. What is even more interesting is that the colour and pattern of the frogs changes visibly as they mature, (as seen in the image to the left and above).

We have found that their ability to reflect infrared in the non-visible develops with the visible change – young frogs almost completely lack the ability to reflect and then they gradually develop this as their skin colour visibly changes. The graph below shows the big difference in spectra between a young and adult frog’s ability to reflect in the infrared. Chris and I regularly meet in the vivarium to collect data from our frogs as they continue to grow and change colour, so that we can document the development of this amazing adaptation. Our findings will be published in the very near future.

Spectra graph

Difference in IR reflectance between a young and adult R.exechopygus (blue line shows level of increased reflectance in adult at approximately 700nm.

             Chris’s Research               Colour Changing Frogs 

My time at the vivarium

photo[3]My name is Kirsty and if you have visited the vivarium within the past few weeks you may have seen me helping out the other members of staff here. I am about to finish studying my foundation degree in zoo management and in order to gain my degree I needed to complete a five week work placement, which is what I have been doing here at the vivarium. Before starting my placement, I already had an interest in herpetology as a hobby and even keep some reptiles at home.

In my past experience I have mainly worked with reptiles and by working at the vivarium I have managed to gain much more knowledge on keeping amphibians.

Conservation is another one of my main interests and it was great to learn about the conservation projects that the vivarium are a part of.

photo[1]The experience of working within a collection that is so focused on conservation helped me learn a lot more about how ex situ breeding projects work and how valuable these projects are. I also got to work with species I had never even heard of before!

While I have been here I have been helping with a range of different things including maintaining the vivariums and helping with some of the animal handling sessions.

photoIt was interesting to learn how the collection at the vivarium varies from other animal collections I have worked with previously and in the future I want to carry on working with endangered reptiles and amphibians, hopefully both in the wild and in captivity. The experience I have gained during my time here at the vivarium will come in very useful when pursuing my future career options.

Finally, I want to say a big thank you to all of the staff here at the vivarium for helping me have the best experience possible and teaching me so much that I didn’t know about these amazing animals.

Theo Jolliffe

Theo Jolliffe can put his umbrella down now he's back in Manchester!

Theo can put his umbrella down with a smile now he’s back in Manchester!

Now back from Central America we actually experiencing better weather here in Manchester than rainy Costa Rica! It was a great trip though and although we got a little washed out at La Selva it was a still wonderful experience for all involved. Apart from our zoology, biology, and plant science students on the field course, this year we were also joined by Digital Media Intern Theo Jolliffe, who was shooting a short film whilst out there.

Theo’s one of our zoology graduates but is interested in ethnology. He’s also highly skilled with a film camera and has been producing some excellent quality short films. Here is a taste of his work in Costa Rica:

Pit Vipers, Floods and Cacao farms         Anna Kell Student Diary – Costa Rica 

Over the rainbow

Costa Rican Rainbow Galliwasp (c) Andrew Gray

Costa Rican Rainbow Galliwasp (c) Andrew Gray

Check out this little chap – a Rainbow Galliwasp, one of Costa Rica’s most colourful lizards. This one’s a very small hatchling, but like an adult galliwasp he usually lives hidden amongst the leaf litter on the rainforest floor. These reptiles belong to a group of lizards called the ‘Anguids’, the same as our European Slow Worm, Anguis fragilis.

In the neotropics 2 species of this group belonging in the genus Diploglossus occur, including this Costa Rican species. The other species, D. millepunctatus, is restricted to Malpelo Island, located off the Pacific coast of Colombia, but what a beauty this is!

IMG_1249Apparently the adult lizards can grow up to 20cm long, and people in northwestern and eastern Panama know it by the names ‘scorpion coral’ and ‘madre de culubra’, This `mother of coral snakes’ is believed by them to be poisonous and so is somewhat feared. From its colourful scales I can kind of see why some might be wary.

Certainly if the bite from this youngster is anything to go by I am pretty sure an adult rainbow galliwasp would give a person walking barefoot through the rainforest a bite on the toe they wouldn’t be getting over it in hurry! lol

SLOW WORMS                       LEGLESS IN CORFU

As views reach 400,000, I would like to thank you so much for following frogblog and invite you to visit the archives (top left) to look back over the past 7 years!

Do you know the way to San Jose..

Carlos de la Rosa, Director takes it all in his stride (c) A Bamford

Carlos de la Rosa, Director, takes it all in his stride (c) A Bamford

Rain, rain, and more rain. It hasn’t stopped for days and now its taking its toll all around the Sarapiqui area. The Sarapiqui River has burst its banks, flooding immediate areas and creating chaos for the local people. Some people who work at La Selva have even had their houses completely washed away. The Director of La Selva has been really wonderful with it all, a top guy – so supportive of all his staff, and all who are staying at la Selva. It’s been the highest flood for many years and its been incredible how fast the water level of the river has been able to rise in such a short time. Roads are closed, many landslides in the surrounding areas, bridges affected too.

The floods have eased, but before the last road to San Jose was also closed or affected further by landslides we decided it was time to pack, unfortunately leave La Selva, and head back to the capital. Everyone in our group is completely safe and sound. The next time time someone tells me it rains a lot in Manchester… :)


Carlos de la Rosa         Raining sheep frogs           La Selva, OTS 

High and dry

Hog-nosed Pit Viper, Porthidium nasutum (c) Amanda Bamford

Hog-nosed Pit Viper, Porthidium nasuta (c) A Bamford

Pit vipers are a group of snakes that have evolved some amazing adaptations. They are highly camouflaged, lightning quick, and have heat sensing pits on their faces to detect the slightest change in temperature. Some species live on the ground and others are totally arboreal, having prehensile tails and living a life fully in the trees.

Here in Costa Rica their are several species of pit viper including ground and arboreal species. When on the Caribbean coast our group was lucky enough to come across 2 highly camouflaged specimens, one a Hog-nosed Pit Viper Porthidium nasuta, a small but highly venomous species, and the other was an Eyelash Viper. Although eyelash vipers can come in an array of different colours, this was well brownish-red.


Eyelash Viper, Bothriechis schlegelii (c) A Gray

Yesterday, as the water levels started to rise at La Selva biological research station, where we are now, due to seriously heavy rainfall, other species of snake which usually reside hidden in the rainforest started to make themselves present. Whilst the snakes here at La Selva are on high alert, those on the Caribbean remain high and dry!


Pura Vida from Costa Rica!

Hola! Chris here,

I’m out with Andrew and the undergraduates in Costa Rica, hoping to take all the work I’ve been doing in Manchester and using it out here to both compare the Museum examples to wild frogs and study frogs that can’t be found anywhere else in the world.

Hyloscirtus palmeri (c) Andrew Gray

Hyloscirtus palmeri (c) Andrew Gray

Whilst out here I’ve had the privilege of working with Brian Kubicki at the Costa Rica Amphibian Research Centre. As such, I have managed to get access to some fascinating frogs. One particular specimen Andrew spotted whilst we were out in the forest with the undergraduates belonged to the rarely found species Hyloscirtus palmeri.

This is an amazing species, originally thought to be a giant glass frog due to its large size and translucent skin. However, it is not a glass frog but the only species in Costa Rica to belong to an unusual South American group of frogs. This species differs from all the other species of Neotropical tree frogs that we have come across in that although it lives in the rainforest it must live close to rivers as it actually lays its eggs under water on submerged large stones or boulders. Finding this rarely discovered frog at the CRARC was a highlight of an already superb trip.

New discovery! - Hyloscirtus palmeri matches the leaves it sits on in the visible and Infrared.

New discovery! – Hyloscirtus palmeri matches the leaves it sits on in the visible and the Infrared. (c) Chris Blount

It was particularly exciting for me to collect data from this frog as early analysis of my results indicate that this species is able to reflect near-infrared light from its skin, a phenomenon I am investigating and a trait never before seen in this genus. The frog however, didn’t care about my research, and seemed to be far more interested in catching a ride on Andrew’s hat!




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