Archives for May 2014

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

Inspired by Nature: Collage Poems

May 26, 2014 by Admin

Inspired by Nature is a themed Croak to entertain you with some of my own and my favourite famous poems written about nature and the outdoors. I hope it will stimulate you to get creative with words and write something yourself. If you do and would like to share them with us, please post them on our facebook page.
Becca, Conservation Youth Worker: Green Pathways Project.

Collage Poems

Now here is something you can do after you have jumped in lots of puddles on rainy day with some kids (or even on your own in the garden when the sun is shining…there’s no restrictions on having fun with words)
A collage poem is exactly what it says on the tin. You know you have that stack of wildlife magazine? The ones which you have read, shared with your neighbours, and read again? Well, give them a new lease of life before they are banished to the recycling bin. All you need to do is scan through them, cut out any words or phrases that leap out at you and arrange them in a poem on a piece of paper. Don’t stick them down, photograph them instead so you can reuse the best words.

Here are two of mine done using a well thumbed copy of Natterchat. Share yours on our facebook page.

Profile of a conservationist – Ute Nüsken, AURING

May 23, 2014 by Admin

This week Froglife meets Ute Nüsken, a German-born conservationist, who lives in Austria with her family. Ute works for AURING a local nature conservation society in the Morova-Dyie-floodplains (March-Thaya-Auen). She specialises in amphibians and aims to inspire as many people as possible about these species. Her favourite amphibians are newts (her local species being the Danube Crested Newt and Smooth Newt).

Why did you choose a career in conservation?

I’ve always been interested in nature and wildlife as my dad used to work in a zoo. After studying Agriculture I moved to the very vulnerable March-Thaya-Auen in Lower Austria and returned to my roots training as a nature-guide. I also took part in an amphibian monitoring project where I learned more about these animals.

What inspires you about working with AURING?

AURING is a local society in the north of the Morava-Dyje floodplains. As more and more lowland rivers are straightened and dammed, many wetland habitats dry out and are lost. In order to stop this development, at least on a local scale, AURING manages replacement habitats, such as the ‘vogel.schau.plätze Hohenau-Ringelsdorf’. Research and active conservation work form the basis of our public relations activities, and thereby also the preservation of this diverse region. Some very ambitious people committing themselves to this special area and I’m proud to be part of it.

Why did you specialise in amphibians?

I am fascinated by amphibians’ biology which enables them to live in so many different ecological niches all over the world. The changes during the metamorphosis are like a wonder, copying evolution in high speed. Amphibians are very good flag-ship species for floodplain-areas as they play such an important role in the ecosystem.

What do you find most inspires the children and adults that you work with about Amphibians?

Everybody knows a frog, hardly anyone knows a newt. And more or less nobody is familiar with the life of amphibians in general. Most people are surprised to find out that amphibians don’t live in the water all their lives. By dealing with these animals people come to know that they are endangered and everybody can do something for their protection. In times where exposure to nature is unfortunately no longer a matter of course, intimate encounters with animals have received a special significance. It offers particular chances for the very reason that these species do not come with the classic ‘cuddle factor’. First insights into the lives of these species arouse curiosity, personal experience and an emotional access which lead to wonder and understanding. Enthusiasm for the creatures of our immediate environment is key for a sustainable way of dealing with nature.

Can you tell us more about the photograph of a young person dressed up as a Danube Crested Newt?

‘One year as a newt’ is an game where young children are “transformed” into newts. They look for hibernation-places/partners/food/reproduction ground and experience metamorphosis by lying down with closed eyes and listening to the story. Our self-designed newt costumes are a great success. Once children have experienced being an amphibian they’re much more aware of their environmental interactions. The predecessor of this, ‘one year as a frog’, was named an Austrian UN-decade projects in 2008 by the UNESCO jury of the advisory committee ‘education for sustainable development’!

What has been your favourite memory while working with AURING?

Children’s laughing-eyes while touching a newt or toad! And comments like “now I will look for amphibians, too!” The general public of today is not familiar with most amphibians, but participants in the AURING projects are able to to establish a relationship with these animals through learning and an intimate, hands-on experience.

What you can do

Find out more about amphibians and reptiles
Take part in projects, attend events, volunteer
Become a Froglife Friend

Tips to avoid waste when gardening

May 16, 2014 by Admin

Slow Worms can often be found in compost heaps. Photo Nick Meade — Photo Nick Meade

Sometimes saving money and being environmentally conscious go hand in hand. More people are getting into the habit of looking around for cheap electricity deals and are prepared to switch providers than in previous years. We are also becoming more aware of the impact of our lifestyles on energy consumption in the home and beyond. In the home, this translates into energy-saving practices such as turning off lights and appliances when not in use, washing clothes and dishes at lower temperatures and choosing energy efficient models when purchasing new appliances.

We are also becoming more conscious of the waste we throw away. Usually we think about food waste and packaging. There are many ways to reduce food waste, including meal planning and freezing meals, and with excess packaging we can vote with our feet to reward retailers that follow environmentally friendly policies. But what about our garden waste? Many people often think of garden waste as not really waste – after all, it’s all green, isn’t it? Surely it will just compost down somewhere. Green waste is not usually sent to landfill because it decomposes under anaerobic conditions – without oxygen – producing methane, a key contributor to global warming.

baby grass snake, LCB May11 So councils usually encourage people to compost at home where they can, or take it to community recycling and composting schemes. Having a compost heap at home is not only a great way of getting rid of your garden waste but also provides a great habitat for slow worms and grass snakes who enjoy the warmer temperatures generated by the decomposing material.

In some areas green bins are provided, but with more councils starting to charge for green waste collection it can all add to household bills. Nearly a third of councils charge households for green bins, and the costs can be up to around £70. Charges are made to subsidise the cost of collection and composting. In some areas, garden waste can account for around a quarter of household waste, so it’s not an insignificant amount of material to be dealing with.

Wildflower garden Fortunately, there are several areas where we can cut back to reduce the amount of material that ends up in the green bin. It’s understandable to want to tidy up grass cuttings after we’ve mown the lawn, but leaving them can not only save on our green waste but also provide nutrients for your lawn. The clippings will naturally begin to be absorbed after two days or so and the added nutrients will encourage thicker and healthier growth. Alternatively, you could consider a slower growing turf, allowing some areas of grass to grow longer to provide safer areas for wildlife to move through or even getting rid of your lawn completely and converting it to a wild flower meadow which will attract bees and encourage biodiversity.

Weed growth can be controlled by a number of different methods. You could try mulching, where a layer of material such as bark is spread over the top of soil. Pulling up weeds when they’re young is easier and they can just be left on top of the soil to dry out. You can also cut out the light weeds need by growing plants that give good ground cover.

Paying attention to your plants and their life cycles will help to reduce garden waste. Shrubs can typically be pruned just when the branches are young. Prunings can be left in the garden as log piles to act as basking spots, shelter and attract food for reptiles. Putting plants in a place that is appropriate for them will cut back on the maintenance required to keep them in good condition. Choose slow growing species and dwarf and alpine plants that won’t create a lot of new growth. To provide the best amphibian and reptile habitats its’ vital to create a variety of plant heights.

What you can do:
• Find out more about wildlife friendly gardening
• Record sightings of amphibians and reptiles using our Dragon Finder App
• Report dead or diseased wildlife to the Garden Wildlife Health project

To find out how you can sponsor a croak please contact:

Lethal Chytridiomycosis in Salamanders

May 14, 2014 by Admin

Fire Salamander

Croaking Science reporter Rhiannon Laubach looks at the history of chytridiomycosis and its impacts on the Fire Salamanders in Europe

The current worldwide loss of amphibians has reached crisis level. Some 40% of amphibian species in parts of Central America are at risk of extinction and there are also large scale losses in Europe, North America and Australia. The main cause for this is an infectious disease known as ‘fungal chytridiomycosis’, chytrid or Bd for short. Click here for a map showing global chytrid distribution.

Chytrid is a fungus that infects vertebrates with spores that grow in the top keratin layers of the infected host’s skin. Symptoms of chytridiomycosis in amphibians include lethargy, lost righting reflex and an abnormal posture. The amphibian’s skin can be ulcerated and slough off in an uncharacteristic way and haemorrhages can occur in the eyes, muscles and skin. The disease is fatal to almost all amphibians (Martel & al 2014).

The earliest evidence for chytrid has been found in a museum collection of African clawed frogs that were collected in Africa in 1938. The exportation of these frogs around the world, for human pregnancy testing and other research, is the likely vector for the spread of the fungus. The first case of chytrid outside of Africa was recorded in North America in 1961 (Laurence 2008). Its spread is made easier because particular species such as the African clawed frog can be affected by the fungus asymptomatically meaning that they do not show any symptoms of the disease.

It used to be thought that there was only one species – Batrachochytrium dendrobatidis – with several different strains that infected all amphibians. However, Dutch scientists studying high mortality rates in the fire salamander (Salamandra salamandra) have discovered a new species of chytrid known as Batrachochytrium salamandrivorans (meaning salamander skin-eating fungus).

In the Netherlands, the fire salamander population has decreased so dramatically that it has brought it to ‘the edge of extinction’ in this country. From 2010 to 2013, the salamander population decreased by 96%. When researchers analysed the dead salamanders to see what was causing the fatalities, they were able to isolate the new species of chytrid.

Salamanders that are affected by this disease, usually die after suffering from anorexia, apathy and ataxia. The infected animals have deep ulcers and shallow erosions all over their bodies which are then colonised by bacteria.

It was necessary for the researchers to find out if the new chytrid species was definitely the cause of the salamandrid mortality. These experiments involved infecting salamanders with chytrid. This research seems quite cruel but was necessary as the researchers needed to see how the fungus infected the salamanders.

Summary of experiment:

Healthy salamanders were inoculated with spores of the chytrid fungus, they all died by day 18. Two healthy salamanders where introduced into the tank, these salamanders where fatally infected.
The common midwife toad (Alytes obstetricans) is easily infected by Batrachochytrium dendrobatidis, toads have been experimentally infected with Batrachochytrium salamandrivorans. The toads where not colonised bythe new fungus species suggesting that it does not affect, or easily affect, other amphibian species such as frogs or toads (Martel & al 2014).

Amphibians are a diverse and charismatic class of species. On a worldwide scale they are increasingly threatened by a wide range of threats such as habitat loss and climate change. Chyrtrid may be what pushes many vulnerable species to extinction. As a result of their plight 2014 has been designated as Year of the Salamander by the Amphibian Survival Alliance and their partners.

What you can do

This can be a depressing topic but there are things that we can all do to help protect amphibian populations:

Find out more, click here to find out more about Chytrid
Try to make your gardens as amphibian friendly as possible
Record and monitor the health of amphibian populations. You can report diseased or dead animals found in your garden to the Garden Wildlife Health project. This will help researchers build a better picture of the state of our garden wildlife and understand the threats that it faces
Support amphibian friendly charities. There are lots of ways you can support Froglife you can: become a Froglife Friend, donate, shop online with Give as you Live (at no extra cost to you) or volunteer

References

Lawerence, D. (2008). Batrachochytrium dendrobatidis, Chytrid disease. Available: http://depts.washington.edu/oldenlab/wordpress/wp-content/uploads/2013/02/Batrachochytrium-dendrobatidis_Lawrence.pdf. Last accessed 2nd April 2014.

Martel,A., Spitzen-van der Sluijs, Blooi, M., Bert, W., Ducatelle, R., Fisher, M., Woeltjes, Bosman,W., Chiers, K.,Bossuyt,F., Pasmans, F. (2014). Batrachochytrium salamandrivon sp nov. causes lethal chytridiomycosis in amphibians. Available: www.pnas.org/cgi/doi/10.1073/pnas.1307356110. Last accessed 31 March 2014.

Archives for May 2014

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