Major
Biology
Anticipated Graduation Year
2024
Access Type
Open Access
Abstract
Ecology can shape variation in mating systems. Spotted sandpipers (Actitis macularius) are migratory shorebirds with a sequentially polyandrous mating system. Females compete for multiple mates, and males care for offspring, including through incubation and chick care. A study of a Midwestern population found that females have larger body mass and feather spots, but we do not know whether this pattern extends to other populations of this species. We studied a California population of spotted sandpipers surrounding Mono Lake. We used PCR to determine genetic sex from blood samples, and we used R to compare morphological traits between females and males. We find sexual dimorphism in several morphological traits, including tarsus, wing, and bill length, as well as body mass, suggesting the Midwestern and California populations have evolved similarly, and both have sexually dimorphic morphology.
Creative Commons License
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When females compete and males care: Phenotypic differences in the spotted sandpiper
Ecology can shape variation in mating systems. Spotted sandpipers (Actitis macularius) are migratory shorebirds with a sequentially polyandrous mating system. Females compete for multiple mates, and males care for offspring, including through incubation and chick care. A study of a Midwestern population found that females have larger body mass and feather spots, but we do not know whether this pattern extends to other populations of this species. We studied a California population of spotted sandpipers surrounding Mono Lake. We used PCR to determine genetic sex from blood samples, and we used R to compare morphological traits between females and males. We find sexual dimorphism in several morphological traits, including tarsus, wing, and bill length, as well as body mass, suggesting the Midwestern and California populations have evolved similarly, and both have sexually dimorphic morphology.