Temperature of the water in a Jonkershoek pond

Temperature is pivotal to the functioning physiology of ectotherms, and for the principally aquatic frog Xenopus laevis the water temperature dictates the temperature of the animals throughout the year. We know that most of the invasive populations of X. laevis were sourced from the South African Cape region in general, and the Jonkershoek hatcheries near Stellenbosch in particular (van Sittert & Measey 2016). 

For the past year, I have had a temperature logger recording the water temperature just above the bottom in a pond in Jonkershoek. 

The same pond has been the source of Xenopus laevis for numerous studies, and likely contains animals that are closely related to those shipped from South Africa all over the world. 

The temperatures between November 2023 and 2024 show that the water reaches maximum temperatures in early February (27.32 C), and a low 6 months later in early August (7.98 C). Despite these extremes, the water temperature varied only 15 C between 10 and 25 C. This is relatively little change compared to the same loggers deployed in Kwa-Zulu Natal (see here). 

Thanks to Martine Jordaan and Andrew Turner who helped with the deployment and collection of this logger. 

A joint meeting of the Herpetological Association of Africa and the African Amphibian Working Group in Wilderness, South Africa: 26 – 29 November 2024

Each of these groups usually meets every two years separately, so it was for the first time in their existance that they met in back-to-back meetings in Wilderness South Africa. First up was the 20th meeting of the AAWG, with plenty of familiar faces from across the globe. 

Next was the 16th meeting of the HAA, which also had great representation and considerably more delegates. 

   

The meeting featured presenters from 9 different African countries: Madagascar, Nigeria, Tanzania, Uganda, Ethiopia, Kenya, Ghana, Namibia and South Africa. This was certainly the best representation of the continent since each of the meetings started. 

The following talks featured MeaseyLab members:

Home and away: the gut microbiome of Xenopus laevis in native and invasive populations

John Measey; Jiankun Yu; Dareen Almojil; Stephane Boissinot; Laurie Araspin; Carla Wagener; Greg Pauly; Reed Ojala-Barbour; Claudio Soto-Azat

The vertebrate gut microbiome is a community largely composed of bacterial, fungal and viral components, whose molecular component equal that of the host. The influence of the microbiome is known to be significant both on an individual basis, and also on population scales in a wide range of host organisms. The gut microbiome is known to be involved with key attributes of animal health, including assimilation of nutrients, immuno-defensive functions and host behaviour. In this study, we used bacterial 16S rRNA amplicon-based sequencing for metataxonomic classification of the gut microbiome of individuals from 12 native populations of Xenopus laevis. These populations were selected to represent the native range of the host species. From the 16S rRNA community profiles, we determine the components of the core microbiome of X. laevis and ask whether deviations from the core are associated with the environmental context in which they live. In addition, we sampled populations from Chile (4) and USA (7) to determine what aspects of the core microbiome are retained by non-native populations. This represents the first time that the microbiome of X. laevis has been assessed across such diverse conditions and provides data that will help understand the role played by the environment within this model organism.

Southern Africa Amphibian Red List Project – updated assessments for the region lead the GAA3

Jeanne Tarrant; Joshua Weeber; Oliver Angus; Adrian J. Armstrong; Ninda L. Baptista; Francois S. Becker; Rebecca M. Brunner; Werner Conradie; Louis H. du Preez; James Harvey; Adriaan Jordaan; Keir Lynch; John Measey; Mohlamatsane Mokhatla; Darren W. Pietersen; Fortunate M. Phaka; Jennifer Swanby; Krystal A. Tolley; Andrew A. Turner; Luke Verburgt

As the most threatened vertebrate class on earth, amphibians are leading the biodiversity extinction crisis. The 2nd Global Amphibian Assessment (GAA2) found that 41.5% of species globally are at risk of extinction, these extraordinary and diverse creatures are experiencing the worst population declines and highest extinction risk of any vertebrate group. South Africa has a good history of updating Red List assessments and has done so consistently since 2004 with the publication of the Atlas and Red Data Book. As some of the first assessments to contribute to GAA3, regional updates are in process for 246 southern African amphibian species. A very high proportion (approximately 74%) are endemic to the region, emphasizing the need to understand their conservation status, and prioritize conservation resources. Over 150,000 records were collated from 16 institutions (including citizen science platforms) and numerous private collections. A team of twenty experts contributed to assessment updates, with the support of the IUCN Amphibian Red List Authority, Amphibian Arc, SANBI and Re:Wild. Applying the IUCN Red List criteria according to IUCN guidelines, the current assessments have resulted in category changes for over 40% of priority species, including assigning a status to all but one Data Deficient species and all Not Evaluated species. Future climate scenarios (2050s) were modelled for South Africa’s threatened frog species and predict a wide range of distributional impacts, which will be exacerbated by ongoing land-use change. 35% of threatened species are likely to be highly impacted by future climate change scenarios. The updated assessments will be published by IUCN in the first half of 2025, and the outcomes of this work will be invaluable in informing an updated conservation and research strategy, the National Biodiversity Assessment, and has already contributed to identifying species in need of urgent recovery in the next decade.

The BioSoundSCape project: Automating frog detection for ecological monitoring in the Cape Floristic Region

Andrew A. Turner; John Measey; Oliver Angus; Colleen Seymour; Alan Lee; Rose Snyder; Festus Adebgola; Leo Salas; Matt Clarke

Monitoring frogs has the potential to provide useful insights into measuring ecosystem health and the management of these ecosystems. Yet currently this monitoring is highly restricted, in space and time consuming. Data acquired from automated sound recording devices can extend the reach of ecological monitoring. The BioSCape project is a large, multi-party collaboration with NASA that aims to relate biodiversity patterns on the ground with remotely sensed, cutting edge spectral imaging that provides very high spectral resolution across the electromagnetic spectrum. One of the novel ways to measure biodiversity is to measure bioacoustic diversity. The BioSoundSCape project deployed a large number of automated sound recorders (AudioMoths) across the Cape Floristic Region and recorded nearly 1 million sound recordings. These recordings are freely available on NASA’s Distributed Active Archive Center. The project set up pattern matching algorithms to detect frog calls of 13 frog species, ran statistical pattern matching, validated results and used the resultant validated sound sonographic signatures for training input to a machine learning (computational neural network) system as implemented by RFCx in Arbimon. From this we calculated diversity indices and present examples of these outputs. Once the entire data collection, processing and analysis can be automated, it can realise the ability for large-scale, frog and ecosystem monitoring.

School for Climate Studies (SCS) and Centre for Invasion Biology (CIB) Annual Research Meeting

Regular readers of this blog will be familiar with the CIB-ARM which is hosted annually in November. This year (after a 2 year interim), we see the new SCS-CIB ARM: a joint venture where Masters and PhD students present on their latest research. This event provides an important forum for networking for post-docs and students alike. For the CIB, the entire Core Team is invited to come together with their students from universities up and down South Africa.

Policy from Science

This year, there was a promient flavour of policy from science both at the national and international level. Prof. Melodie McGeogh (Monash University) provided a plenary from her perspectives after participating in the recent IPBES report Thematic Assessment Report on Invasive Alien Species and their Control. 

In addition, Peter Lukey (Chief Director: Environment Knowledge and Information at DFFE) provided an overview of his experience as a policy maker in the South African government.

In addition to these plenary talks, we had a host of marvellous talks from postgraduate students from the SCS and CIB. This included Jonathan Bell who presented an update on his MSc work on improving the efficacy of the Gutteral Toad eradication programme.

Another great ARM from another year of research for 10s of students working on invasions and climate change. We look forward to next year when the intersection of these two disciplines will be dissected in more detail.

A talk for the University of Portsmouth

Readers of the blog will be familiar with my repeated visits to the University of Portsmouth and in particular the European Xenopus Resource Centre (EXRC). In January 2024 (see here) I became a Visiting Researcher, School of Biological Sciences, University of Portsmouth, and so during a brief visit to Portsmouth this week, I was asked to give a talk to the School.

The EXRC is a special place for anyone working on Xenopus as they hold breeding stock for anyone in Europe working on Xenopus frogs. Recently, we were able to supply them with some gametes from the progeny of wild caught animals from South Africa. I hope to report more on that project here on the blog in future.

Matt Guille leads the EXRC and received a flashing Xenopus neon sign for the EXRC lab.

Measey, J. (2024) What can biological invasions teach us about rapid evolutionary change? 1 November 2024 School of Biological Sciences at University of Portsmouth

A testimonial from Sam and the importance of saying thank you

Today was another long day. I got back from the office to find a whole bunch of messages on different platforms and I made myself a cup of tea before sitting down and going through them. One was a voice note from Sam Peta. Sam did a MSc with me and James Baxter-Gilbert, defending his thesis back in 2022 (see here). The voice note really surprised me. I've asked Sam, and he's given his consent to transcribe it here for the blog:

“Morning John, I hope you're good.

I think I forgot to tell you this but some time last year I had a job interview. I think it was a research field assistant for the Cape Parrot Project in Hogsback. It was like a brief interview to ask about who I am and what I do what was my MSc was about.

I told the lady, I don't remember her name, that I was supervised by Prof John Measey, and she said “Oh, I know John Measey!”

I was like whoa, okay, that's nice. And then she started telling me about her project with the leopard toad and that was quite amazing.

Even with one of the guys that I work with, he said that you taught him, I think when he was in Stellies.

So yeah, I think that the point that I'm trying to make is that I wouldn't be where I am now if it wasn't for you. The amazing skills that I've learned from you, the amazing mindset that I have when it comes to research, or looking at the world the way I look at things. So I'm grateful for the support that you've given me all these years, and now I have the confidence to say that I would like to believe that there's a great future in terms of research, and in terms of finding my way around. They're the small parts of life when it comes to working, is because of the skills that I've learned from people like you and James [Baxter-Gilbert] have helped me so much. I'll forever be grateful for that.

Even when I hear people talk about you, I get that kind of inspiration to say, okay, I've been under the supervision of one of the most incredible scientists in the world. So yeah, I'd like to believe that, hopefully in some way we can just keep in touch enough to work together at some point in the future. Yeah, I'm just wanting to say, before I start my new working day, thanks so much John for everything.”

Firstly, I’m incredibly grateful to Sam for reaching out and saying such nice things. It’s so great to hear that there’s been a lasting positive effect on students that have worked in my lab. Second, is that I have learned that it’s so very important to actually say these things to people. To actually thank them instead of just thinking that it would be nice. It’s not just important that they hear you say it, but also because you might be surprised what you hear in reply.

Here’s my response to Sam:

“Hey Sam – Thanks so much for your kind words. I think what you forget is that this does not only go in one direction. I learn an incredible amount from my students, including you. This is one of the things that makes being an advisor such an enjoyable experience, because I get to work with such enthusiastic people. It’s really my privilege to have worked with you.”

I used to think when I heard aged professors talking about their wonderful postgraduate students that they were just paying lip service to the team of people who really did all the work, but with no thanks. However, what I’ve learned, over the fullness of time, is that for many professors they truly do appreciate their team and the benefit goes both ways.

So, if you have read this far and you have someone in your life that you are thinking – yeah, they really helped me – I’m asking you to reach out to them now and say thank you. If you can, leave a voice note (like Sam did) so that they can hear your voice and know that you really do mean it. It will mean so much to them, and like Sam you may well get some words of wisdom to continue to propel you forwards.