Sexual selection is defined by Charles Darwin as “the advantage which certain individuals have over others of the same sex and species, in exclusive relation to reproduction.”  The term itself usually conjures up an image of a peacock: a male bird with incredibly elaborate plumage ornaments which females lack.  This is due to the fact that traditionally, studies of sexual selection have focused on male ornaments, both visual and acoustic.  In this situation, males are the showy sex bearing elaborate ornaments  and females are the choosy, cryptic sex.  To date, there have been few studies of female ornamentation, therefore my Masters research will focus on ornamentation and mutual sexual selection in the Royal Flycatcher (Onychorhynchus coronatus).

            Royal Flycatchers are small tyrannid flycatchers which inhabit Central and South America.  They are of great interest to me because both males and females have a crest that they can display prominently or conceal completely.  Males display bright red crests with black spots, while females display bright yellow crests with black spots.  Historically, it has been theorized that these crests play a role in both mate choice and predator defence strategies, however no one has studied these phenomena to any great extent.

            The goals of my Masters thesis are to characterize the breeding system of the Royal Flycatcher and to investigate the signal function of their crests as it relates to sexual selection.

             From August 2005 to May 2006, I worked on my Honours thesis at the University of Windsor in Dr. Daniel Mennill’s lab.  Using recordings made by multi-channel microphone arrays that had been set up to capture the vocalizations of one of Dr. Mennill’s study species, the Rufous-and-white Wren (Thryothorus rufalbus) which had inadvertently also captured the vocalizations of Plain Wrens (Thryothorus modestus), I characterized the vocalizations of a previously-unstudied population of Plain Wrens.  For more on microphone arrays, check out both Dr. Mennill’s homepage, and the homepage of one of his graduate students, Lauren Reed.

            Plain Wrens are neotropical wrens which belong to a group known for their expert singing and duetting behaviour.  They inhabit Central America, from Mexico to Panama along both the Pacific and the Caribbean slopes.  A population of Plain Wrens inhabiting the Caribbean slope of Central America has previously been studied by Mann et al. (2003), who found that these wrens sing highly complex duets.  This Caribbean population is believed by some to represent a distinct subspecies of the Plain Wren, which they refer to as Canebrake Wrens.

            These wrens were recorded in Santa Rosa National Park, Costa Rica, where the University of Windsor maintains a field house for use by several researchers.  I analyzed months of recorded data using Syrinx, a program developed by John Burt (University of Washington).  With Syrinx, I was able to locate and label all Plain Wren songs recorded on the multi-channel arrays.  Once I had found all Plain Wren songs recorded within eleven of these arrays, I was able to measure the fine acoustic characteristics of male and female song, again using Syrinx.

            The results of my Honours thesis were published in The Condor in August 2007.

  Publications

            Cuthbert, Jessica L. and Daniel J. Mennill.  2006.  The Duetting Behaviour of the Pacific Coast Plain Wren (Thryothorus modestus).  Condor 109: 686-692.  (PDF)

Presentations

            Cuthbert, Jessica L.  May 2006.  The Duetting Behaviour of the Pacific Coast Plain Wren.  Honours Colloquium, University of Windsor. 

            Cuthbert, Jessica L.  March 2006.  The Duetting Behaviour of the Pacific Coast Plain Wren.  Ontario Biology Day, University of Western Ontario.