Noble Lab

It’s been a massive couple months for Fonti Kar, who has pulled off an amazing thesis. Congratulations! She remained cool, calm and collective right to the end and wrapped up her thesis with plenty of time to spare!

Fonti did two huge experiments that jived well together. Her first chapter explored the predictors of contest outcome in our favourite lizard, Eulamprus quoyii. This is one area we lack a lot of information on and Fonti has shown that there are some very interesting assessment stages that Eulamprus proceed through before escalating to fights. Actually, escalated fights that result in fighting and biting between two males only occurred in 38% of contest pairings.  Interestingly, given the differences between escalated and non-escalated (i.e. contests resolved through signalling) contests, she predicted that the predictors of contest outcome should vary depending on these assessment stages. While most of her predicted traits did not affect contest outcome (which is interesting given she did 116 contests!), she did find a prior winning effect that influenced the probability of initiating a contest, which was a strong predictor of contest outcome (if you initiated you won!). In support of her prediction, she also showed that the importance of initiating a contest depended on whether the contest escalated or not. Males that initiated in non-escalated contests had a much higher probability of winning whereas it didn’t seem to make a difference if they decided to initiate a contest that resulted  in physically fighting with another male.

Fonti’s second chapter made use of this huge contest experiment to look at the role of social dominance (whether you win against other males during a contest) on social information use. Making use of the contest data she paired males of known contest history together and randomly assigned one of these males (dominant or subordinate) to be the experimental lizard and the other was designated the demonstrator lizard. Dominant males were winners and subordinate lizards the losers of contests. The demonstrator was trained to flip lids to access a mealworm under a rewarded lid and was then allowed to show the experimental lizard this task. Importantly, we have shown that E. quoyii do use social information to learn such a task (click here to learn more about that work), but only young lizards used social information to learn. However, age and dominance often go hand in hand in lizards and so Fonti attempted to control for age by assigning equal numbers of large and small males across three treatment groups: 1) Where the dominant male was the demonstrator; 2) the subordinate male was the demonstrator and 3) a control group, which was a mix of dominant and subordinate experimental lizards that were just shown the other lizard but not doing the task. She specifically predicted that watching a male that was dominant or subordinate to yourself would affect how you use social information. In other words, subordinate male lizards would pay more close attention to those big macho males, while macho males wouldn’t care what some small little male was up to. Her results were interesting, but to make a long story short, social dominance didn’t seem to affect social information use in anyway and actually her results were similar to those found in previous work comparing old males – they didn’t seem to use social information at all! This is pretty cool because it suggests that age may really be the big driver of social information use for these particular tasks.

All this hard work required a massive celebration (a night out on the city) and a special trophy for Fonti to remind her of her lizard contests thanks to her fellow MSc friends (See below).