Females from a wide variety of taxa display elaborate ornaments and aggressive behaviours that are similar to those expressed by males. Although recent empirical investigation has demonstrated that ornamental traits and behaviours of females may function by attracting mates or signalling competitive ability when competing against conspecifics for access to mates and resources, less is known about how such traits influence the mating success of free-living female birds. For my research, I experimentally examined how variation in plumage brightness and behaviour of female tree swallows (Tachycineta bicolor) influenced their mating success. Plumage brightness of females had no influence on investment in parental care or mating strategies of males, or the quality of social mate paired to the female. These results suggest that bright plumage is not a signal of attractiveness preferred by male tree swallows. In contrast, I report evidence that plumage brightness of female tree swallows is involved in agonistic interactions with conspecifics. Females whose plumage brightness was enhanced to signal high quality were less able to retain their nest site than females whose plumage brightness was reduced to signal low quality. This suggests that females displaying bright plumage may be challenged by conspecifics of high quality to test the quality signalled by bright plumage, and is supported by the finding that females displaying enhanced plumage brightness suffered social costs, such as delaying breeding and producing low-quality nestlings. Despite these costs, females in the enhanced plumage brightness treatment mated with extra-pair males that were higher quality than their social mate. Behaviour of females, manipulated by elevating testosterone (T), lowered the proportion of extra-pair offspring in the broods of T-treated females. Females manipulated so that the androgenic and estrogenic actions of T were blocked also produced fewer extra-pair iii offspring, and suggest that the androgenic and/or estrogenic actions of T influence extra-pair copulation behavior of female tree swallows. In conclusion, my results show that plumage brightness and behaviour of female tree swallows influence their mating success, and highlight the importance of studies experimentally manipulating ornamental and behavioural traits of free-living female birds prior to breeding. iv

Models of sexual selection assume that female mating preferences are heritable and, thus, repeatable for individual females across multiple mating episodes. Previous studies of the repeatability of female preference have examined individuals in captivity and focused presumably on social mate choice. However, extra-pair mating is widespread and can also influence sexual selection. We examined the repeatability of extra-pair mating in a wild population of tree swallows (Tachycineta bicolor) by experimentally inducing females to lay two clutches in rapid succession within the same season. We found that the proportion of extra-pair young and the number of extra-pair sires were highly repeatable for individual females. However, the repeatability of specific extra-pair sires was low. We suggest that this unusual pattern of mating may be due to females maximizing the heterozygosity of their offspring.

In today's increasingly technological society, a workforce proficient in science, technology, engineering, and mathematics (STEM) skills is essential. Research has shown that active engagement by K-12 students in hands-on science activities that use authentic science tools promotes student learning and retention. Mobile laboratory programs provide this type of learning in schools and communities across the United States and internationally. Many programs are members of the Mobile Lab Coalition (MLC), a nonprofit organization of mobile and other laboratory-based education programs built on scientist and educator collaborations. A recent survey of the member programs revealed that they provide an impressive variety of programming and have collectively served over 1.2 million students across the US.

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