My research focuses on the influence of natural and sexual selection on communication and mating behaviours of animals, and the application of new technologies for monitoring and conserving populations of wild animals. I am interested in how individual animals send and receive information, how they use information to make decisions, and how their communication behaviour is related to the populations, communities, and environments in which they live. My research integrates individual-scale behavioural research with population biology, community ecology, natural history, and environmental stressors such as traffic noise, all within an evolutionary context. By integrating traditional field-based observational research with powerful new technologies, my research yields novel insights into the behaviour of wild animals.
Postdoctoral research:Noise presents a significant barrier for acoustic communication because it lowers the effectiveness of signal transmission, which in turn affects animals’ choices related to survival and reproduction. Many species of mammals, birds, fish, and anurans produce altered acoustic signals in noisy environments. My research integrates the effects of anthropogenic noise on animal communication networks. I am presently combining observational and experimental data to investigate how social interactions are altered in the presence of anthropogenic noise using observational recordings, experimental playback, and Acoustic Location System technology. My research will provide data on the scope of the effects of noise, the extent of behavioral plasticity, and the response at a community level for several wild animal species.
My PhD research focused on mating behaviours and communication networks in wild- and laboratory-reared crickets. Traditionally, behaviours thought to be important in determining reproductive success have been studied in isolation. I investigated the interplay between communication, lifespan, aggression, mate choice, sperm competition, and social environment in crickets to better understand the relationships between these naturally- and sexually-selected traits.
Central questions of my PhD research include: do males honestly signal their quality to females, do males experience trade-offs in components of sexual behaviour (e.g. aggression and signaling effort), do acoustic signals change as males age, do individuals behave differently when being watched by others, and how is the quality of a male's signal related to how much effort he invests into signaling? I outline the main results of my dissertation below.
I am interested in both components of sexual selection: aggression between males, and male advertisement to females. To examine how these mechanisms are related to each other, I investigated the relationship between mate attraction and aggression in male crickets. I tested whether successful fighters produce sexy signals or if there a trade-off between these traits. In contrast to birds, signaling is not an honest indicator of aggression in crickets. My research reveals that acoustic signals may be primarily used for mate choice and less important to rivals.
The phenotype-linked fertility hypothesis predicts a positive relationship between investment in mate attraction and ejaculate quality. I investigated the relationships between pre- and post-copulatory male traits and female mating responses in crickets. I quantified signaling effort and quality and then mated males to virgin females to examine how male signals are related to female choice and ejaculate quality in crickets. I found no relationship between mate attraction signals and male fertility or female preference. While female crickets may receive benefits by choosing males based on acoustic signal characteristics, whether the benefits are a result of genetic quality, seminal fluid contents, or some other male trait remains unknown.
Evidence that males signal their age is inconclusive despite female preference for older males in many taxa. I recorded the songs of male crickets continuously and analyzed the quality and quantity of the signals produced over the crickets' lifetime. Males decreased signaling effort with age, suggesting females may use male signals to distinguish between age classes. Males that signaled most lived longest, supporting the handicap signaling prediction that high-quality males bear costs better than low-quality males. This study is the most thorough exploration of lifetime signaling patterns in crickets to date.
Animals often behave differently when being watched, but most research on communication network behaviours comes from vertebrate animals so the ubiquity of these effects is unknown. I conducted an experiment to investigate audience effects on aggression in crickets. I found that audience type may impose different costs and benefits for competing males depending on whether they win or lose and whether they are socially experienced or not. Field-captured winners dynamically adjusted their contest behaviour, potentially to gain a reproductive benefit via female eavesdropping and to deter future aggression from rivals.
Watch a short clip of a fight between two crickets, including a victory song and dance once the fight is over.
During my MSc, I studied vocal behaviour in black-capped chickadees, focusing on male-male song contests from a communication-network perspective. I used a large Acoustic Location System to passively record the songs of entire neighbourhoods of territorial birds. My research was the first to quantify patterns of temporal- and frequency-variation in natural countersinging exchanges by free-living animals. I found that both song matching and overlapping were frequently used communication strategies during countersinging contests. My observations reveal that contests containing frequency matching had significantly more instances of overlapping than nonmatched contests, which suggests that chickadees use frequency matching as a conventional signal of aggression in a graded system of signals. I also found that the post-contest singing behaviour of chickadees did not appear to function as a victory display; surprisingly, most often the subordinate male who lost the contest was the one who vocalized after the contest.
I also conducted a playback experiment that revealed that territorial male chickadees listen in (eavesdrop) and respond to interactions occurring outside of their territory boundaries. Interestingly, the effect of playback was not limited to the focal male -- males with nearby territories also responded to playback with elevated song rates. My playback study revealed that dyadic interactions can have both an immediate effect on adjacent neighbors and also a communication network ripple effect, effecting the behaviour of more distant neighbours.
While my MSc research focused on daytime singing interactions of chickadees, I also concurrently collaborated with Dr. Jenn Foote on studies of the dawn chorus singing behaviour of chickadees.