The CIB holds its final ARM as a hybrid event

Every year the CIB holds an Annual Research Meeting as an opportunity for students to present their work to an audience of peers and the CIB network of Core Team Members, affiliates and associates. This year sees the last meeting in the role of the CIB under the DSI-NRF Centre of Excellence. The 2020 and 2021 events were both online affairs. 

Three MeaseyLab students presented their research findings at the meeting:

Laurie Araspin started the show by presenting a chapter from her PhD work on "Locomotor performance in Xenopus laevis".  Laurie is a co-tutelle student with Anthony Herrel's MECADEV lab at the Natural History Museum in Paris.

Next Dan van Blerk presented a chapter of his MSc work on "The impact of invasive fish on ghost frog tadpoles", work that he conducted in collaboration with Josie Pegg from SAIAB. 

Lastly, Jonathan Bell presented some preliminary results from his MSc work on "Optimising conditions for controlling the invasive guttural toad". Jonathan is conducting his MSc at the CIB, but also works full time for the City of Cape Town invasive species unit.

Congratulations go to Laurie and Dan, both of whom won runners up prizes in their categories for best presentation.

Andrea finishes his postdoc in the MeaseyLab

Dr Andrea Melotto has been working in the MeaseyLab for two years.  Andrea's project was to investigate the invasive population of Asian spiny toads, Duttaphrynus melanostictus, in Madagascar and compare these to the source population in the native range in Vietnam. Andrea performed a standard set of morphological, performance and behavioural traits.

He visited Madagascar in January and Vietnam in August 2022. Both of his trips were severely constrained by COVID restrictions, and each represented a triumph against the odds in his actually managing to get there. This work is in collaboration with Angelica Crottini from CIBIO, Portugal.

Andrea also worked on a project comparing Western Leopard Toads, Sclerophrys pantherina, to Raucous Toads, S. capensis, and Guttural Toads, S. gutturalis. We are eagerly awaiting the publication of this very exciting study.

It was great to have Andrea in the MeaseyLab and we wish him all the best in his future endevors. Watch this space to see the output of Andrea's work.

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

Getting data from Asian Spiny toads in Vietnam

Back in January this year, MeaseyLab postdoc, Andrea Melotto, finally made it to Madagascar to collect data from an invasive population of Asian Spiny toads, Duttaphrynus melanostictus.  In Madagascar, Andrea performed a standard set of morphological, performance and behavioural traits with toads from the invasion core and expanding invasion front. Now Andrea has made it to Ho Chi Minh City in Vietnam, thought to be the site from where the Malagasy toads originated. There, Andrea is working with Dr. Dao Tran from University of Science-Ho Chi Minh City. 

The toads are abundant in and around the city, and are a regular sight sitting on the lily pads of water features. 

Andrea measures a recent capture while Thu enters data on the laptop.

Khoi enters data on the laptop for the second trial while Thu chases a toad down the racetrack and Phi videos the session. 

Measuring behaviour at night means working under red lights and using CCTV to record how the toads interact with their environments.

Downloading data from Hobo loggers

Sometimes you have to take a leap of faith and leave expensive equipment in the field in order to get much needed long-term data. This is what we did last February in a trip to KZN where we made an elevational transect while collecting African clawed frogs for Laurie (see Blog Post here). We placed four loggers at sea level, 1000 m, 2000 m and 3000 m asl. Sadly, the logger at 3000 m asl disappeared very soon after we placed it in a deluge of floods that hit Lesotho in March 2021. That meant that there were still three more loggers out in the field that needed to be retrieved. 

Fortunately, with the help of Bongani Ntloko from Letseng mine, we were able to redeploy another Hobo logger into a pond with Xenopus at ~3300 m asl. The results after one year (March to March 2022-23) are amazing.

Firstly, note that the scale on the y-axis only goes up to 20 C, and the water never gets that warm. For most of the year, the water is below 10 C. Only from around mid-October to late-March is the water above 10 C. This means that the frogs in Lesotho are more than half of their year in water less than 10 C. Even in summer, the water still regularly dips below 10 C on a daily basis.

Happily, the logger from 2000 m asl at the Fat Mulberry was retrieved by Marggie and she brought it to Stellenbosch where we could download the data.

This month I made a trip back to KZN to retrieve the outstanding loggers from near Dalton and at Bonamanzi:

The temperature of the water in a dam near Dalton never went below freezing, but it did get quite cold (as well as getting hot in the summer). 

Meanwhile at Bonamanzi, the temperature was nearly always above 10 C, and even went above 40 C! Contrast this with Lesotho when the water temperature rarely went above 10 C!

You may remember that Bonamanzi was where we had our traps vandalised by crocodiles. Happily though, you can see that the logger (right) didn't come to the same fate. The logger near Dalton (left) was still tied to the same stone sunk in the dam. 

Thanks to friends in Lesotho, we redeployed one of these Hobo devices there. Because you can replace their batteries, they are fantastic and just carry on working. We are hoping that the new logger won't go AWOL!