Live for the day—or maybe longer depending on the weather! 

Blue whales live for more than 100 years, while adult mayflies may come and go in a day. Our own lifespan has increased by nearly 10 years over the past generation. We are used to a world where the life expectancy of animals is expected to vary by a few years, but what if your lifespan was linked to the weather? Researchers from University of Cape Town, South African National Biodiversity Institute, and Stellenbosch University have discovered a frog whose likelihood of survival appears to be linked to the amount of winter rainfall in South Africa’s biodiverse fynbos biome.

Rose’s mountain toadlet comes out every winter to breed, but the amount of time the males spend waiting in puddles for females to arrive influences life-expectancy of these tiny toadlets. At only 20-30 mm long, these voiceless toadlets are easily overlooked, but the researchers, Francois Becker, John Measey, Krystal Tolley, and Res Altwegg, undertook a mark-recapture study over 7 years, to reach the finding that whether toadlets live long (4+ years), or just one year, depends on the weather.

Surprisingly, ‘good weather’ for frogs (wet winters) was found to reduce survival as animals are thought to spend more time out in the open, while ‘bad weather’ (drier winters) means they abandon the breeding site quicker, resulting in these toadlets living to try again another winter.

The correlation between survival and winter rainfall is truly remarkable, but the exact mechanism determining survival needs more work, and time is running out. The latest IUCN assessment is that this species is Critically Endangered and with climate in the area changing, it could be that changes in the winter rainfall regime could add to existing threats for this special species.

While this is the first known example of a vertebrate with extreme changes in survival that appear to be weather dependent, it may simply be due to a lack of sufficient research on the world’s smaller animal species. The researchers suggest that this kind of weather induced longevity change may be far more common than we are aware, prompting more concern about how changes to the climate may affect wildlife.

Read more about it here at American Naturalist

The 13th Annual Research Meeting of the CIB - Congratulations Natasha!

The 13th Annual Research Meeting of the CIB took place at Stellenbosch University Thursday and Friday.

Presentations were made by Nitya, Natasha and Marike.

From top right:

1. The judges receive their thank you presents from Dave Richardson: Piero Genovesi, Laura Meyerson, Petr Pyšek & Tim Blackburn.

2. Marike answers a question from the audience (and who was part of the winning pod)

3. Natasha gives the talk that won her best runner up for a PhD presentation

4. Nitya wows the audience with the size of his bullfrog. 

Well done to the whole lab who put on a magnificent set of froggy presentations. Especially well done to Natasha!

Xenopus not so aquatic

A new paper using the data from Andre's MSc project shows that African clawed frogs move large distances overland (up to 2.4 km). The 3 year study found that 5% of frogs moved between 8 ponds in the study area of Kleinmond. This amount of movement may be so much that these frogs can no longer be considered a metapopulation. 

We got the top slot on the PeerJ website (again!). 

The really surprising result is the amount of movement between sites, and the animals that were moving. We found no evidence of the smallest size classes of frogs moving between ponds. This would turn the dispersal paradigm on its head for this species. For most pond breeding frogs, it is the metamorphs and juveniles which are responsible for most of the dispersal within a population. This may not happen for X. laevis as smaller animals are so much more susecptible to dessication. The study isn't over and we will be following up on this idea in years to come. 

De Villiers FA, Measey J. (2017) Overland movement in African clawed frogs (Xenopus laevis): empirical dispersal data from within their native range. PeerJ 5:e4039 https://doi.org/10.7717/peerj.4039

Read the article here

Thanks to @Xen_Ben for the blog title!

Working hard at the invasive syndromes workshop

Three days of talking about invasive syndromes was hard work for all involved, set in fantastic surroundings. 

The guest list read like a who's who in invasion biology. Most important were the rising stars many of whom have received training from the CIB. In years to come, we expect that the most well known invasion biologists will be the freshest of faces here.

Thanks to Ana Novoa and all at the CIB who worked so hard to make this event possible. Additional thanks to all who came from far and wide to participate in what was a fascinating workshop. 

Watch this space to see a link to the forthcoming publication on invasion syndromes...

Spatial frogs tick all the boxes for Zishan's MSc

Zishan Ebrahim's MSc thesis on using spatial data for the conservation of frogs on the Cape peninsula passes all the necessary paperwork. 

It's been great working with Zishan over the past couple of years and we're all really pleased to see his thesis pass the final hurdle. Congratulations Zishan!