ABS 2013 – Agonism with Adam Reddon


My name is Adam Reddon, and I study the behavioural biology of social living. I have a particular fascination with both aggression and sociality and I endeavor to better understand these behaviours through the integration of functional, developmental and mechanistic perspectives. My Ph.D. work focused on social decision making in the contexts of grouping behaviour and resource contests in a highly social cichlid fish. I am finishing my PhD at McMaster University this month and will soon be moving to Montreal to take up a postdoctoral fellowship at McGill University in Simon Reader’s research group. During my postdoctoral work I plan to examine the effects of maternal experience on the social behaviour and physiology of her offspring in guppies.


Email: reddonar@mcmaster.ca

Website: http://www.science.mcmaster.ca/psychology/people/262-adam-r-reddon.html

Google Scholar: http://scholar.google.ca/citations?user=MM1KKXcAAAAJ&hl=en

Twitter: @adamreddon

Fight Club

Among those that study how animals interact with one and other, there are two basic groups: those who are mostly interested in what the boys have to say to the girls (or vice versa), and those who are mostly interested in how animals settle disputes among members of their own sex. The former group is certainly larger than the later, as evidenced by the fact that this Animal Behaviour Society Meeting had around 60 or 70 talks on sexual selection broadly defined, including a couple of plenaries, while there was but one session on agonism, or fighting as it is better known. Furthermore, the lone agonism section happened to fall into the last slot of the last day, a time when many conference attendees are often running short on attention span or have wandered off to explore whatever lovely locale in which the conference is set (Boulder, CO has this in spades). So, you can imagine my trepidation when I discovered that my talk was in the last slot of this last session, on the last day, in a topic that warranted only the lone session out of around 80 or so. I envisioned speaking in front of the other speakers from the session, 100 empty chairs and perhaps a janitor catching a nap in the back row. Much to my delight, the agonism session was very dynamic and well attended! This, I think can only be credited to the exceptional talks that joined my own in rounding out this session. All five of the other talks very interesting and engaging. I learned a great deal and very much enjoyed this session. Below are some brief descriptions of each of the 6 talks:

Sara Decker, University of Wyoming – Sara’s talk was about dominance hierarchies in a very interesting species of bird, the long-tailed mannequin. Long-tailed mannequin males form groups and work together to attract females. Only the dominant most male gets to breed though, and he has a second in command that is next in line for breeder status. Sara found that if both of these two top ranked males disappeared at the same time, the group descended into chaos and in-fighting, which apparently long-tailed mannequin females do not like, as they stop coming around until the chaos dies down and the hierarchy becomes stable again.

Bruce Lyon, University of California Santa Cruz – Bruce talked about dominance interactions in gold-crowned sparrows. Gold-crowned sparrows, like many birds, use badges of status to settle disputes without needing to escalate to costly violence. Males of this sparrow have a bright yellow patch of feathers atop their head. Birds with a bigger patch are dominant over those with a smaller patch. In a staged interaction between two birds, you can change who wins by using paint to give one bird an artificially larger patch. Interestingly, Bruce presented data showing that this manipulation doesn’t work if the birds are from the same flock and already know each other. Presumably, they remember the other bird, know what that bird is really like and hence are not fooled by the new dye-job.

Chad Johnson, Arizona State UniversityThe rapid expansion of Phoenix, Arizona from small desert settlement to one the largest, most bustling metropolises in North America has posed many challenges for the local flora and fauna. One animal that seems to be doing ok with the new neighbors is the western black widow spider. This poisonous character is doing so well it has become a major urban pest. Interestingly, Chad presents data showing that although western black widows are super abundant in the city, the city-dwellers are actually less healthy than their desert counterparts that have to eke out a living under much tougher circumstances. Chad found that this unexpected difference seems to owe to the fact that the city spiders eat mostly a particular cricket species, which is low on phosphorus, a vital nutrient for western black widows. Basically, city spiders are gorging themselves on junk food, which lets them reproduce quickly, but spiders from more natural areas are getting a more varied and complete diet, resulting in better overall health.

Russell Ligon, Arizona State University Russell studies aggressive interactions in veiled chameleons, which can change their body colour rapidly, and may do so to communicate with one another. Russell found that the brightness of a chameleon’s body predicted its likelihood of escalating to physical fighting, while the chameleon with the darker head was signaling submissiveness and was unlikely to win the fight.

Vikram Iyengar, Villanova University Vikram presented data on sexually selected trait divergence in a pair of related damselflies. These species may live together in the same areas, or in different areas. When they co-occur, one species tends to have smaller spots on its wings than it does when the other species isn’t around. Previous research has shown that these wing spots are attractive to females. Vikram’s study showed that the wing spots also draw the ire of males of the other species, causing them to attack more often. Vikram’s data suggests that males in areas of overlap have been selected for smaller wing spots because although it makes them a bit less sexy, it also saves them some costly beatings.

Adam Reddon, McMaster University – Last up to bat was my talk. I told the audience about a recent study comparing the decisions during fights between two closely related species of cichlid fish, one of them highly social (frequent star of this blog, Neolamprologus pulcher) and the other (Telmatochromis temporalis) much less so. I predicted that because the social species may have more information about their opponents before a fight because they have interacted with them before, and because the social species may have a greater overlap in interests with their opponents, the social species would have less costly fights. I also predicted that the social species may find a way to end a conflict that allowed them to stay in the same area and continue to interact with their opponent after the fight, whereas the less social species may just run away and go somewhere else. My results confirmed both of these predictions, suggesting that changes in the way animals fight may be tightly linked to their social system, how they live with and get along with other members of their species. The morning of my talk, I found out that the paper this data was drawn from was accepted for publication in the journal Behaviour. I considered this a good omen, and sure enough, my talk went great. I was happy with my performance and got lots of positive feedback afterwards. Best of all, lots of smart people hung in there to the end and listened to me speak. It was a great way to end a great meeting.

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