How to translate text using browser tools
1 September 2009 No Assortative Mating Based on Size in Black Guillemots Breeding in the Canadian Arctic
Lisha L. Berzins, H. Grant Gilchrist, Gary Burness
Author Affiliations +

The Black Guillemot (Cepphus grylle) is a monomorphic, socially monogamous member of the Alcidae. Although aspects of their breeding and foraging ecology have been extensively studied, less is known about possible sex-based differences in morphology, nor whether Black Guillemots mate assortatively based on body size. Using molecular techniques, we identified the sex of 26 male and 21 female Black Guillemots captured in the Canadian Arctic, and measured six external body measurements: outer tarsus length, wing length, culmen length, bill depth, head plus bill length and body mass to test for sexual size dimorphism (SSD) and assortative mating. Overall, males were 1.7% and 8% larger than females in outer tarsus length and bill depth, respectively. Within breeding pairs, bill depth was the most dimorphic trait. Despite these morphological differences no evidence of assortative mating based upon body size was found. Thus, mate choice for body size does not appear to be an underlying mechanism of SSD in bill depth in Black Guillemots.

Lisha L. Berzins, H. Grant Gilchrist, and Gary Burness "No Assortative Mating Based on Size in Black Guillemots Breeding in the Canadian Arctic," Waterbirds 32(3), 459-463, (1 September 2009).
Received: 23 September 2008; Accepted: 1 January 2009; Published: 1 September 2009
Black Guillemot
discriminant analysis
mate choice
sexual size dimorphism
Get copyright permission
Back to Top