Turn up the colour: male frogs use bright colours to avoid confusion at the pond

Imagine being a frog during the chaos of the breeding season and navigating the gathering crowds around the pond. How do you know who might be a suitable mate let alone whether they are male or female? One solution is colour. If one sex, typically males, is able to turn on some bright colour that not only clears up any confusion about sex identity but also may signal something about male quality.

While bright displays are common in the animal kingdom, they come at a cost because they also draw the unwanted attention of predators. One solution to this problem is dynamic colour change whereby an animal can switch between conspicuousness and camouflage, a phenomenon that is well known in flag ship organisms such as chameleons and cephalopods (octopus and cuttlefish) but much less studied in frogs. It turns out that frogs around the world have evolved this ability independently. Grant Webster studied colour change in the whirring tree frog (Litoria revelata) for his honours and an obvious extension of that work was to get to grips with the incidence of dynamic sexual dichromatism (DSD) in frogs globally. At about that time, Rayna Bell and Kelly Zamudio published their review and comparative analysis of frog colour change. After contacting Rayna, we teamed up to expand the work and to also examine the evolution of DSD in hylid frogs, given the high incidence in this clade. It’s been a long road, but now the work has finally been published in the 20 September issue of Journal of Evolutionary Biology.

This, sometimes painstaking, research uncovered 178 species with dynamic sexual dichromatism from 15 families and subfamilies. Interestingly, it is the frog family Hylidae (treefrogs) that really stands out. Of the currently recognised 900+ species, 95 are capable of dynamic colour change and a disproportionate number occur in Australia. So, what drives this process? There are many questions about the relative roles of the environment and social behaviour that remain unanswered. However, our comparative analysis revealed an interesting finding—frogs that first evolved the behaviour of breeding in large aggregations were also likely to evolve dynamic sexual dichromatism. In the hustle and bustle of a large breeding scrum, being able to quickly identify the opposite sex and choose a suitable mate is made a lot easier with a bit of bright colour.

The paper can be accessed here, or e-mail us for a PDF. We will also make a PDF available once the full version with page numbers is available.

Bell, R. C., Webster, G. N. and Whiting, M. J. (2017), Breeding biology and the evolution of dynamic sexual dichromatism in frogs. J. Evol. Biol.. doi:10.1111/jeb.13170

Brains and Brawn: dominant lizards are better learners too!

Note: this blog post is republished from Fonti’s web site

Dominant individuals tend to have greater monopoly over food and mates and therefore have more offspring compared to subordinate individuals. Are these successes attributed to greater cognitive ability? Or are dominant individuals just better at freeloading from their clever subordinate counterparts?

We investigated . . . → Read More: Brains and Brawn: dominant lizards are better learners too!

PhD opportunity – visual ecology of lizards

We are looking for a highly motivated and suitably qualified candidate to conduct a PhD program of research on reptile visual ecology, commencing in 2017.

The successful applicant will be guided to develop a project to investigate the visual performance and ecological adaptations of a range of lizard species with differing life history traits. . . . → Read More: PhD opportunity – visual ecology of lizards

Hot off the press! Roommates are not all they’re cracked up to be (if you’re a lizard)

Recently, myself and collaborators published our study that found – social experience has a crucial role in development of a family-living lizard. We also discovered that despite their social nature, the Australian tree skink (Egernia striolata) does not necessarily thrive in a ‘share-house’ environment.

Egernia striolata from Gluepot, South Australia

Group- and family-living . . . → Read More: Hot off the press! Roommates are not all they’re cracked up to be (if you’re a lizard)

Hot off the press! Toads at the invasion front are more prone to explore and take risks

By Jodie Gruber

The cane toad (Rhinella marina) has been spreading rapidly across northern Australia since its introduction to control sugar cane beetles in 1935. While toads have been the focus of considerable research, we still have a poor understanding of how behavioiural traits vary across the range, particularly with respect to traits that . . . → Read More: Hot off the press! Toads at the invasion front are more prone to explore and take risks

Julia Riley interviewed on ABC radio!

Take a listen to Julia Riley discussing our latest publication on the influence of social environment on learning in tree skinks (Egernia striolata). The interview was with Marc Fennell on ABC radio.

This work, led by Julia, has been published in Animal Cognition:

Riley, JL., Noble, DWA., Byrne, RW., Whiting, MJ. 2016. Does social . . . → Read More: Julia Riley interviewed on ABC radio!

Skinks and Ladders: A family-living lizard’s learning ability is not affected by their home environment

By Julia Riley

A family-living lizard’s ability to navigate through a complex maze is not linked to how they were raised

We have found that the learning ability of the Tree Skink, a lizard that lives with family, is not linked to growing up with others. These lizards were . . . → Read More: Skinks and Ladders: A family-living lizard’s learning ability is not affected by their home environment

Dispatches from the field: frogging at the DMZ

After attending the 8th World Congress of Herpetology in China, I had a night and a day in South Korea before flying on to my next destination, the US. What to do? As it turned out, I had a windfall (thanks Julia). I met Amaël Borzée, a PhD student from Seoul National University. Amaël . . . → Read More: Dispatches from the field: frogging at the DMZ

The 8th World Congress of Herpetology

Note: the following post is by Julia Riley and also posted on her web page.

On 14 August 2016, a small contingent of the Lizard Lab headed from Sydney, Australia to Hangzhou, China for the 8th World Congress of Herpetology. Our fearless leader, Martin Whiting, as well as James Baxter-Gilbert and I were the Lizard . . . → Read More: The 8th World Congress of Herpetology

The Slow Professor: Challenging the Culture of Speed in the Academy

Book Review

A Riley & Whiting Collaboration

Julia Riley’s Review:

First, I would like to say as an expat Canadian researcher, I am happy to say that two Canadian professors wrote this book! Woot!

This book proposes a means to tackle the effect corporatization of higher education has on universities. Their ‘Slow’ Professor Manifesto . . . → Read More: The Slow Professor: Challenging the Culture of Speed in the Academy