Sexual Dimorphism, Female-Female Pairs, and Test for Assortative Mating in Common Terns

Sexual size dimorphism and discriminant functions for predicting the sex of Atlantic Puffins (Fratercula arctica)

“…We were able to achieve a higher rate of correct classification in our discriminant function for Witless Bay puffins (88 %) in part because we specifically measured both members of pairs when creating the function (Sandvik 2001;Fletcher and Hamer 2003;Nisbet et al 2007). Our initial discriminant model for Witless Bay puffins with four variables (wing length, culmen, bill depth, head ?…”

Interregional Breeding Dispersal of Adult Roseate Terns

“…Coulson et al 1983;Chardine and Morris 1989;Craik 1999;Fletcher and Hamer 2003;Devlin et al 2004;Bluso et al 2006;Nisbet et al 2007;Shealer and Cleary 2007;Herring et al 2010), we found head length to be the most reliable trait for sexing birds in the hand. Although mean head lengths of males and females differed by only 3.2 mm (approximately a 4% difference), there was less overlap between the sexes in this than in other measurements (Table 1).…”

“…If both members of a pair had been measured, including mate characteristics in the discriminant functions increased accuracy, as in other terns (Fletcher and Hamer 2003;Devlin et al 2004;Nisbet et al 2007;Shealer and Cleary 2007). The stepwise analysis produced a discriminant function with the following variables: head length, tail length, and mate's head length (Table 2).…”

“…However, subtle sexual dimorphism is present and discriminant function analysis (DFA) can be used to sex terns based on field measurements (e.g. Coulter 1986;Chardine and Morris 1989;Craik 1999;Fletcher and Hamer 2003;Devlin et al 2004;Bluso et al 2006;Nisbet et al 2007;Shealer and Cleary 2007;Reynolds et al 2008). In the Roseate Tern (Sterna dougallii) males are, on average, larger than females (Gochfeld et al 1998), and we report here on the first discriminant functions developed for use in sexing this species.…”

Using Morphometry and Molecular Markers for Sexing South American, Cayenne and Royal Terns Breeding in Patagonia, Argentina

“…The ability to sex individuals is particularly important to answer many ecological and behavioral questions and to effectively develop conservation and management actions. For example, sexing of individuals has been fundamental for the study of tern foraging patterns (Bluso-Demmers et al 2008), feeding behavior (Wagner and Safina 1989), mating systems (Nisbet et al 2007), demography (Dittmann et al 2005), and differential effects of pollutants (Herring et al 2010b).…”