Catch Xenopus in the Matroosberg

Although we had already collected African clawed frogs ( Xenopus laevis ) at 3,300 m asl in Lesotho (see here), at 1650 m asl in Sutherland (see here), these only represented two of the clades in the region. In order to get animals at high altitude from the southeastern clade, we needed a high altitude site with African clawed frogs. Happily, the areas around Matroosberg are at 1,300 m asl, and we managed to find frogs at the farm and in a mountain stream.

The stream water is a deep 'tea brown' from the phenols that come from the fynbos in the mountain catchment. The pools in the stream were several meters deep. That's a long way down for a trap to sit. 

As you can see, we missed one frog as it escaped from the trap as we pulled it from the water. But there were more than enough animals captured to complete the sample size that we were looking for.

African clawed frogs from the Southwest altitudinal transect

Any attempt to collect animals across an altitudinal transect is going to involve going high and low. Getting high, often involves getting cold, and that's exactly what we got when we made our highest collections at Sutherland. In driving rain, and temperatures below 10 C, we managed to get a good sample of frogs from ~1600 m asl, just outside of Sutherland town. 

From there it was down hill. We collected tadpoles using a colander in Prince Albert, drove through the Swartberg Pass, and finally ended up in the beautiful Nature's Valley where we captured the first ever record for Xenopus laevis   from the area, as well as completing our sampling and our transect. At every stop, we unpacked huge suitcases to form a fully functioning lab to make sure that the samples were tip top.

The research was driven by Boissinot Lab postdoc Dareen Almojil, who will stay on in Stellenbosch for some more sampling. Also featured is the very able Sandra Goutte, and of course, the Boissinot Lab boss, Stephane Boissinot.

Read about the Northeastern transect that was completed in March 2021 with Laurie Araspin and Carla Wagener here.

We look forward to seeing what comes of these samples once they are sequenced back in NYU-AD!

A talk for Stellenbosch University library

I was invited by the library at Stellenbosch University give a talk for their Open Access week. The theme was UNESCO's "It Matters How We Open Knowledge: Building Structural Equity."

As this theme fitted perfectly with my forthcoming book "How to publish in the Biological Sciences", I provided a talk giving a brief outline of the state of publishing. 

Growing up in a new world

In a new paper published in Neobiota, Max Mühlenhaupt and colleagues bring tadpoles from invasive and native (both urban and rural) populations of the Guttural Toad (Sclerophrys gutturalis) into a common garden. You may remember the exploits of Max back in late 2019 and early 2020 (if not, then you can read about them here, here and here).

Max looked at lots of traits of the tadpoles as they developed over time. This included morphology swimming performance and developmental rate. What he found is that animals from all populations were identical morphologically and their performance did not diverge. However animals from the invasive population in Cape Town developed significantly more slowly.

In the video clip below, you can see how Max stimulated the tadpoles to perform. From videos such as this, he was able to measure swimming performance of individuals.

Although the COVID-19 pandemic interrupted the end of this experiment, we expect that the slow development of tadpoles from Cape Town would have resulted in their larger size at metamorphosis. This is yet another example of adaptation in an extremely short period of time. Guttural Toads were first discovered in Cape Town in the year 2000. Just under 20 years from when Max started his experiment.

Read more here:

Mühlenhaupt M, Baxter-Gilbert J, Makhubo BG, Riley JL, Measey J (2021) Growing up in a new world: trait divergence between rural, urban, and invasive populations of an amphibian urban invader. NeoBiota  69: 103–132. https://doi.org/10.3897/neobiota.69.67995

Getting a reporter's view

When I got an email from Wendell Roelf, Reuters news agency, asking for information about invasive trees and any frogs that they may impact, there was one clear example that sprung to mind. We have been monitoring the rough moss frog on the Klein Swartberg near Caledon for around 10 years now. In that time the invasion from pine trees on the massif has been spectacular. Since a fire in 2011, we have seen the mountain turn from blackened earth to a carpet of pine seedlings, and now thick sways of pines that are so dense that individuals are as thin as sticks but have reached 3 to 4 m in height. 

In amongst all this the Rough Moss Frog, Arthroleptella rugosa, can be found in fewer spots on the mountain. Where it is still present among the pines the calls are far fewer. Oliver Angus, Honours student in the MeaseyLab, has been using aSCR to determine the density of the remaining populations of the Rough Moss Frog. Stay tuned to see the outcome of his findings here.

The MeaseyLab (myself, Oliver Angus and Andrea Melotto) took Wendell Roelf and cameraman Mike Hutchins up the Klein Swartberg where we introduced him to Andrew Turner from CapeNature, Lampie Fick chairman of the Klein Swartberg nature conservancy, and a team of contractors who are cutting fire breaks that will form the basis of a rotational burn on the mountain that should see it free of pines in the future. After getting the full picture, Wendell took himself off into the pines to jot down notes for his story.

It was a fun day and great to see that Wendell wrote a great article that has been syndicated all over the world.

To read Wendell's article, click the image below:

They also put together a neat video that shows what it takes to remove invading pine trees: