tadpoles

Thanks to our wonderful volunteers!

June 20, 2016 by Admin

This month we’d like to highlight the time, passion and creativity that our volunteers bring to our projects.

All over the UK, the Froglife teams create & restore habitats and hold events to help educate the public on the importance of conserving amphibians and reptiles and saving the habitats they depend on. At all of these events, across the countryside and cities we have a strong team of volunteers who are always there to help spread the conservation message and get mucky to help our little frogs, toads, newts, snakes and lizards! vol KW2016

These volunteers not only give us their time, they also share their talents with us by regularly taking photos and creating fantastic videos after we’ve completed projects at sites.

So here’s a few bits that they’ve shared with us:

This amazing underwater video of tadpoles in Olive Branch Community Gardens, was shared to Rebecca Neal, Conservation Youth Worker, for Peterborough Green Pathways by one of her volunteers. Froglife put the ponds in 5 or 6 years ago through the Wildlife Ambassadors project, and this video clearly shows us that the frogs like the ponds we made!

This selection of videos come from Katie Garrett, one of the London Dragon Finder volunteers. Katie often comes along to our events and work days, gets muddy and still manages to take amazing photos and videos! Check her out on twitter, @katieggarrett, as she often posts more images and short videos of the amphibians and reptiles she sees when she’s out and about. When she’s not volunteering with us, she also volunteers with Honduras Amphibian Rescue and Conservation Centre, making films for their conservation efforts. She’s a Herp Hero!

So again, a MASSIVE thanks to all our volunteers from everyone here at Froglife!

This is how SMILEY you make us! — You make us all **SMILE!**

Flexibility of life history events in the Common Frog

May 29, 2014 by Admin

5. Getting bigger (Rob Williams, 2011)

Croaking science is a new way for student volunteers and scientist to explore what’s occurring in the world of Science. Croaking Science looks at science facts, new research or old debates which are inspired by or affect amphibians and reptiles, and then communicates this in layman’s language to a wider audience. The aim of the feature is to provide a platform for those starting their foray into the world of science communications as well as established scientists. We welcome any submissions from students and scientists. Please note that the views expressed in the articles are not those of the Froglife Trust.

Croaking Sceince reporter Rhiannon Laubach looks at the history of Chytridiomycosis and it’s impacts on the Fire Salamanders in Europe

– See more at: http://www.froglife.org/2014/05/14/lethal-chytridiomycosis-salamandars/#sthash.ugsmA3E1.dpuf

Croaking Sceince reporter Rhiannon Laubach looks at the history of Chytridiomycosis and it’s impacts on the Fire Salamanders in Europe

– See more at: http://www.froglife.org/2014/05/14/lethal-chytridiomycosis-salamandars/#sthash.ugsmA3E1.dpuf

Croaking science is a blog for student volunteers and scientists to explore what’s occurring in the world of Science. Croaking Science looks at science facts, new research or old debates which are inspired by or affect amphibians and reptiles, and then communicates this in layman’s language to a wider audience. The aim of the feature is to provide a platform for those starting their foray into the world of science communications as well as established scientists. We welcome any submissions from students and scientists. Please note that the views expressed in the articles are not those of the Froglife Trust.

Croaking Science reporter Rhiannon Laubach looks at the flexibility of life history events and its significance for Common Frogs

Not all members of the same species undergo metamorphosis at the same rate. Metamorphosis can be described as a life history event, the transformation from the larva (tadpole) to the juvenile adult (froglet). The size of an animal, or the development stage it is at, can affect the chances of an individual surviving the winter, in temperate climates.

Most tadpoles metamorphose into froglets in the same year. However, some common frog tadpoles can over-winter in this larval stage and then transform into frogs the next spring. This phenomenon has been recorded with a greater frequency in recent years, being reported by both the media and scientific literature. There has not been much investigation into what causes this and it is not known at which point in its development an individual will determine if it will over-winter as a tadpole or not.

A recent report studied the growth and development of a population of common frogs (Rana temporaria) tadpoles throughout one year in order to see if the rate of development of tadpoles would influence in what form they over-winter. Laboratory studies were carried out to complement field work.

8. Long legs (Rob Williams, 2011) The methods of the study were as follows: between May and January of the following year, tadpole development at the field site was monitored by randomly collecting tadpoles and taking them back to the laboratory to be measured and their stage of development was noted. If an individual had not started metamorphosis by November it was considered to be over-wintering as a larva. Water temperature was continuously logged for the duration of the study. This data was used to calculate the mean fortnightly temperature. For the laboratory study, the tanks where kept at mean fortnightly temperatures and they had either a high or low food availability scenario. The tadpole’s development and condition were also recorded.

9. Front legs growing under skin (Rob Williams, 2011) The study confirmed that tadpoles do over-winter at the study site. At the site, shortly after hatching the larvae began to form two distinct development groups. One group consisted of waves of individuals that grew on and then metamorphosed. The second, smaller, group continued to grow but did not metamorphose and this decision to over-winter as tadpoles was carried out very early in their development.

It is unclear what causes this, it could be genetic or “local environmental cues triggering a particular developmental pathway in a genetic subset of the population” (Walsh& al 2008). Tadpoles that over-winter have an advantage, as they don’t have to invest so much energy into development and can use more energy for growth. Larger tadpoles will metamorphose into larger frogs. Larger frogs have an advantage. In the laboratory there was no over-wintering. The tanks where kept at a mean fortnightly temperature, which does not reflect the temperature fluctuations at the study site. Food availability was not shown to have an affect on over-wintering.

This study shows that the possibility of a tadpole over-wintering is determined very early in its development. Over-wintering of larvae might be the tadpoles’ response to local environmental conditions but temperature does not seem to be the main variable for determining this (Walsh& al 2008).

17. Freedom... (Rob Williams, 2011)

Reference
Walsh, P.,T., Downiel, J., R., Monaghan, P.. (2008). Larval over-wintering: plasticity in the timing of life history events in the Common Frog. Journal of Zoology. 276 , 394-401.

Photos: Rob Williams

Croaking Science: Gastric-brooding frogs – a uniqueness lost forever?

November 27, 2013 by Admin

Croaking science is a new way for student volunteers and scientist to explore what’s occurring in the world of Science – science facts, new research or old debates which are inspired by or affect amphibians and reptiles, and then communicate this to a wider audience in their own words. The aim of the feature is to provide a platform for those starting their foray into the world of science communications as well as established scientists. We welcome any submissions from students and scientists. Please note that the views expressed in the articles are not those of the Froglife Trust.

This is the time of year where you may be getting together with friends and family for meals all over the world. When you do, think about what this frog went without, to look after it’s young. From one of our new Croaking Science Volunteers Hannah Graves.

Gastric-brooding frogs were discovered in Australia in the 1970’s ⁽¹⁾. There are two known species, the Northern (Rheobatrachus vitellinus) and the Southern (R.silus) ⁽²⁾, neither of which has been seen in the wild since the 1980’s ⁽³⁾. It isn’t known exactly what caused the demise of the two species, it is believed that logging and disturbances to the water quality in their habitats may have had an effect on the Southern species ⁽⁴⁾ and wide spread forest fires and habitat destruction could be implicated in the loss of the Northern species ⁽⁵⁾. As with all amphibian populations globally, the fungal disease Chytridiomycosis can’t be ruled out⁽¹⁾.

As the common names suggest, this genus of frog had a very unusual way of caring for their young. After the female had mated, she swallowed her eggs! This meant that the tadpoles could develop in her stomach safe from predators ⁽⁶⁾. After six to seven weeks the tadpoles metamorphosed into young frogs and crawled back out of the female’s mouth ⁽⁴⁾. During this brooding period the female switched off the production of hydrochloric acid to prevent digesting her young ⁽⁷⁾. This meant that she couldn’t eat whilst carrying her young. Just four days after her young emerged, the female’s digestive system returned to normal and she resumed eating ⁽⁴⁾. Unfortunately, as the two species are now classified as extinct ^{(1) (8)}, it is unlikely we will ever learn the secrets of how they managed to shut down their digestive systems and then start them up again.

Sadly, this story of discovering a new species only to lose them a few years later is all too common ⁽⁹⁾, and with them we lose their untold stories.

What you can do

Support initiatives to inspire the next generation of herpetologists (scientists that specialise in amphibian and reptiles) including our conservation and education work .

Even our “common” species are declining in some areas. If nothing is done now, they may not be there in the future. Use our Dragon Finder app to report any of your amphibian and reptile sightings (applicable to species found in the UK). So that the location of your local populations are recorded.

References

(1) Meyer, E.; Newell, D.; Hines, H.; May, S.; Hero, J.; Clarke, J.; Lemckert, F. (2004). Rheobatrachus silus. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.1. Downloaded on 01 October 2013.

(2) IUCN (2013). IUCN Red List of Threatened Species. Version 2013.1. www.iucnredlist.org Downloaded on 01 October 2013.

(3) Hines, H. (2002) Recovery plan for Stream Frogs of South-east Queensland 2001-2005. Environmental Protection Agency, Queensland, Australia. Downloaded on 01 October 2013.

(4) Tyler, M.J. and Davies, M. 1983. The gastric brooding frog. M.J. Tyler, eds., Croom Helm, London.

(5) Hero, J. and Morrison, C. (2004). Frog declines in Australia: global implications. Herpetological Journal 14:175-186.

(6) Tyler, M.J. and Carter, D.B. (1982). Oral birth of the young of the gastric-brooding frog Rheobatrachus silus. Animal Behaviour 29:280-282.

(7) Tyler, M.J.; Shearman, D.J.C.; Franco, R.; O’Brien, P.; Seamark, R.F.; Kelly, R. (1983). Inhabitaion of gastric acid secretion in the Gastric Brooding Frog, Rheobatrachus silus. Science 220:609-610.

(8) Hero, J.; McDonald, K.; Alford, R.; Cunningham, M.; Retallick, R. (2004). Rheobatrachus vitellinus. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.1. Downloaded on 01 October 2013.

(9) Wake, D.B. and Vredenburg, V.T. (2008). Are we in the midst of the sixth mass extinction? A view from the world of amphibians. Proceedings from the National Academy of Science 105:11466-11473.

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