Moving from correlative to mechanistic approaches of modelling African Clawed Frog distribution

We have already produced a number of different correlative models to predict the distribution of African Clawed Frogs (Xenopus laevis) in Europe. In the latest paper by Philipp Ginal (PhD student of Dennis Roedder from Museum Koenig, Bonn), we take a new approach by using data from the physiology of several different populations of both adults and tadpoles of X. laevis.

What this new model tells us is that despite tadpoles being apparently frail and far less robust than adults, when you compare the physiological data generated by Natasha Kruger and Carla Wagener in their theses to that of adult frogs (data produced by Mohlamatsane Mokhatla and Laurie Araspin), the tadpoles actually have a broader thermal niche. This means that instead of adult distribution being limited by tadpoles, it's actually the other way around. 

This rather surprising result means that we are not going to see any reduction in the forecast range by including tadpoles in our model. Moreover, the adaptations seen in the adult French Xenopus have resulted in a far greater potential distribution for this group of animals in Europe, compared to the potential for frogs from either the Western Cape or Kwa-Zulu Natal.

Our results show the value of having more than one life-history trait in a species distribution model, even though this might not provide the expected result. In addition, we demonstrate the importance of rapid adaptation in invasive species that mean that they have far greater invasive potential than the populations from which they were founded.

To read more:

Ginal, P., N. Kruger, L. Araspin, M. Mokhatla, J. Secondi, A. Herrel, J. Measey and D. Rödder (in press) More time for aliens? Performance shifts lead to increased activity time budgets propelling invasion success. Biological Invasions https://doi.org/10.1007/s10530-022-02903-6 pdf

Performance of native and alien guttural toads

You may remember that some time back, there were many trips to exotic places by the toad team (see here and here). Although there have already been a number of papers that have come out from these trips (Baxter-Gilbert et al., 2020; Baxter-Gilbert et al., 2021; Baxter-Gilbert et al., 2022) - here is the final one of this series led by former MeaseyLab post-doc James Baxter-Gilbert (James is now employed at Mt Allison University - see here).  

In this manuscript, we based our question around the pathway that the toads had taken to invasion. Starting out in rural KZN, the toads have invaded the city of Durban before being moved (as urban toads) to Mauritius in 1922 (yes - 100 years ago!). There they were released in cane fields, quickly moving into urban areas and from there into the natural forests of the island. Toads were moved from urban Mauritius in 1925 to Reunion. Once again, they moved through the urban environment before entering the natural forests. Hence, we asked whether advantages gained in the urban environment could have helped these toads in their invasion pathway.

For most of the traits that we studied, we found no indication of help coming from the toads having passed through an urban filter before their invasion. However, the climbing performance trait did have results that suggested that urban areas, with their many barriers, could have preadapted toads so that when they invaded the islands they were able to do better at climbing - eventually moving up the trees!

Read more about this study here:

Baxter-Gilbert, J.H., Riley, J.L., Wagener, C., Baider, C., Florens, F.B.V., Kowalski, P., Campbell, M., & Measey, J.(2022) Island hopping through urban filters: anthropogenic habitats and colonized landscapes alter morphological and performance traits of an invasive amphibian. Animals 12(19), 2549; https://doi.org/10.3390/ani12192549 pdf

Another interview with Daniel Shea from Scholarly Communication 

You may remember that back in April 2020, I put up a blog post about an interview I conducted with Daniel Shea for his Scholarly Communication podcast (see here). I found that interview very demanding as Daniel had done a great job of reading the entire book and had some very challenging questions. So I felt that I had to be better prepared for this second interview, this time about the newly published 'How to publish in Biological Sciences'. 

Once again, Daniel surprised me with his insightful and probing questions. I'm not going to write too much here about the interview, but why not take a listen and see what you think?

Thanks to Daniel for making this such an enlightening and challenging interview. 

Remember that you can read the book for free at www.howtopublishscience.org:

Measey J (2022) How to publish in Biological Sciences: a guide for the uninitiated. CRC Press, Boca Raton.  ISBN: 9781032116419 https://doi.org/10.1201/9781003220886                            

Great to see Xenopus people meeting at the 21st European Congress of Herpetology

This year's European Congress of Herpetology is being held in Belgrade, and there were lots of Xenopus talks!

From left to right: Felix Deiß, Anastasia Regnet, Dennis Rödder, Nicholas Wei Cheng Tan, Natasha Kruger and Philipp Ginal

Among these were Dr Natasha Kruger presenting work from her PhD on a Xenopusreciprocal exchange experiment with tadpoles:

Kruger, N., Secondi, J., du Preez, L., Herrel, A. & Measey, J. (2022) Is there no place like home? Response of African Clawed frog tadpoles to novel environments

 and Philipp Ginal talking about his recent work on modelling the difference between adult and tadpole time in Europe:

Ginal, P., N. Kruger, L. Araspin, M. Mokhatla, J. Secondi, A. Herrel, J. Measey & D. Rödder (2022) More time for aliens? Performance shifts lead to increased activity time budgets propelling invasion success. 

I'm happy to say that both papers are in press, and you can read them here (even if you didn't see the presentations!).