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Nitya talks at Island Biology Conference

11 July 2019

Nitya talks at Island Biology 2019

Some of you may remember that Nitya won a prize for the best popular article at the CIB ARM back in November 2018 (see blog post here). The cash prize gave him enough money to attend an international meeting, of his choice. Nitya opted to attend the Island Biology 2019 meeting on Reunion. He managed to roll some other work into the trip, by joining the mascarene toad team on Mauritius (see blog post here).

Now Nitya is presenting his talk at the conference in the symposium: Future steps to fight against invasive species on islands.

I'm sure that it will be well received. 

Read more about Nitya and his PhD thesis research here. Read my blog about visiting the Andaman Islands here.

Mohanty, NP, Hui, C & Measey, J (2019) Invasion dynamics of an amphibian with frequent human-mediated translocations on the Andaman archipelago. Island Biology, La  LaRéunion 8-13 July 2019.

  Frogs  Lab  meetings

Tadpole anti-predator strategies

10 July 2019

What do tadpoles do when they sniff a predator?

Natasha Kruger asked this question of populations of the invasive African Clawed Frog in a study conducted with Jean Secondi in France. Clawed frogs have been invasive there for ~30 years, but a number of studies are suggesting that they have already started to adapt to the local conditions (see here). 

As an invasive frog, once you’ve been moved to the new environment, not only do you have to cope with new conditions, but your tadpoles do too. This means that tadpoles should be able to respond to new predators, as well as ones that they already know. This was the basis for the work that Natasha conducted on tadpoles of the invasive African clawed frog, Xenopus laevis, in France.

Natasha tested to see how tadpoles reacted to known and unknown predators. For example, she tried cues from aquatic snails and another invasive species in France, the red swamp crayfish, Procambarus clarkii.

Tadpoles were placed into fresh water in a cup with a cross drawn across the bottom. The cue was then dropped from above and their reaction filmed. She was particularly interested in the number of times that the tadpoles crossed the lines in the cup – showing a response to the cue.

Like other tadpoles, African clawed frogs were found to decrease their activity in the presence of a predator. That is they crossed the line less often when cues were given, compared to novel cues.

The early version of the manuscript is now up online and you can enjoy reading it here:

Kruger, N., Measey, J., Herrel, A., & Secondi, J. (in press) Anti-predator strategies of the invasive African clawed frog, Xenopus laevis, to native and invasive predators in western France. Aquatic Invasions

  Frogs  Lab  Xenopus

Submitted - Biological Invasions in South Africa

05 July 2019

Biological invasions in South Africa. Our book is written!

With 31 chapters and 104 contributing authors, our forthcoming book is going to be an epic tome. The book, now submitted, will be part of the Invading Nature - Springer Series in Invasion Ecology. It's been nearly a year since we made the proposal to the publisher to collect together as much information as possible on biological invasions in South Africa. Our approach was to be encyclopaedic, and so we inveigled as many of our colleagues involved invasion science as we could.

The book is divided into 7 parts:

  • Part 1: provides a broad overview of biological invasions in South Africa
  • Part 2: deals with the current situation
  • Part 3: details the underlying factors influencing invasions
  • Part 4: addresses why invasive species are important in the South African context
  • Part 5: covers aspects of the management of invasions in South Africa
  • Part 6: explores additional aspects relevant to biological invasions
  • Part 7: looks to the future of biological invasions in South Africa

Led by Brian van Wilgen, the book is edited by five Centre for Invasion Biology Core Team Members: Brian, Dave Richardson, John Wilson, Tsungai Zengeya and myself. It was no small task, but over countless meetings my fellow editors made it all an enjoyable experience. Brian kept us on track and generally cracked the whip.

Brian looks over his shoulder to make sure there are no large animals approaching

We look forward to the end of the year when we'll be able to offer everyone unlimited access to pdfs of all the chapters.

For those of you interested in my contribution, I led two chapters and contributed to six more (see details here).

Measey J, Hui C, Somers M (2019) Terrestrial vertebrate invasions in South Africa. In: van Wilgen BW, Measey J, Richardson DM, Wilson JR, van Wilgen BW (eds) Biological invasions in South Africa. Springer, Berlin. 

This is a review of the invasive terrestrial vertebrates in South Africa. It contains species acounts of 30 animals, and details their distributions and impacts. We aim to provide a useful perspective on the extent of current invasions within the country, as well as providing a resource for much of the research that has been conducted on them.

Measey J, Robinson TB, Kruger N, Zengeya TA, Hurley BP (2019) South Africa as a donor of alien animals to other parts of the world. In: van Wilgen BW, Measey J, Richardson DM, Wilson JR, van Wilgen BW (eds) Biological invasions in South Africa. Springer, Berlin

This is an unusual twist on the invasion paradigm as here we consider species native to South Africa which have invaded places in other parts of the world. For me, this chapter was quite an eye-opener as the more I read, the more species I found (and the longer the chapter grew). We finally ended with ~34 species with some really great stories from drug barons to the director of nature conservation; those responsible for introducing these species are a pretty maverick bunch.

Keep watching this space...


Tiny Toads meet their match on Mauritius

02 July 2019

Marauding Mauritius for Tiddly Toads

This month, the MeaseyLab has relocated to the Mascarene Islands of Mauritius and Reunion to conduct research on their invasions of Guttural Toads, Sclerophrys gutturalis. These toads were introduced, from the port city of Durban in South Africa, into Mauritius in 1922. Now, nearly 100 years later, they can be found nearly everywhere on the island. Intriguingly, they are a fraction of the size of the animals found in Durban. I visited Mauritius a while back (see blog post here), and worked with Claudia Baider and Vincent Florens to visit some toad populations in different parts of the island. Now the lab is back and working on the toads.


Carla has been seen with Guttural Toads before (see here and here), but this is her first time in Mauritius. Not only is she collecting faecal matter for her MSc on the Guttural Toad microbiome, but she’s using the opportunity to collect some skin swabs for our collaboration with Morne du Plessis at the National Zoological Garden, Pretoria (see here).


James only just started his post-doc in the MeaseyLab (see here). He’s using the model system of the Guttural Toad in Africa to understand their invasion success through the investigations of divergent phenotypic traits and rapid, localised evolution. Mauritius is his first field stop, and he’s making the most of every moment by putting the toads through their paces.


Nitya and Julia are helping out James and Carla with their work but adding their own research talents into the mix. We’ll come back to that in future when the publications start rolling out!


All together, the fab quartet make a talented team to take on the challenge of these invasive amphibians on Mauritius. You can be sure that those tiddly toads are no match for the four of them.


Back to the Klein Swartberg

20 June 2019

Winter Outings listening for frogs

Those of you with long enough blog memories will recall Debra Stark, and her work on the Rough Moss Frog (Arthroleptella rugosa) on the Klein Swartberg near Caledon (see blog post here). Debra's work was to assess the entire population of Rough Moss Frogs, a feat only possible as they occur there and nowhere else. Debra's work is now in press as a chapter in a book (see Stark et al here), but the frogs continue to call every winter on the mountain.

As one of the projects for Alessandra to learn the aSCR technique (see here), we decided that another estimate of how A. rugosa are doing on the Klein Swartberg was in order. So today we set out to explore the mountain again.

The march of pines over the mountain has been horrific since we were last there. And that's not all. In this picture below you'll see eucalyptus, pines and hakea all taking over the mountainside, with just a small amount of fynbos visible.

The numbers of frogs we heard were probably the lowest on any trip that I've made. A combination of poor winter rains and invading alien species drinking up all of the ground water. We'll be back soon assessing the total population again.

  aSCR  Frogs  Lab
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