Many key questions in behavioral ecology can be profitably addressed by applying endocrinological techniques. This research will examine the physiological basis of plasticity of reproductive behavior in a biparental burying beetle (Nicrophorus orbicollis). Correlative analyses will be used in two ways to implicate specific hormones in the regulation of reproductive behavior. First, titer curves for juvenile hormone and ecdysteroids will be developed for both males and females across a complete reproductive cycle. Second, environmental variables will be manipulated to alter the quality and duration of paternal care; these behavioral responses will be matched to concurrent hormonal responses. To examine the casual relationship between hormones and behavior, hormone treatments will be made in an attempt to induce changes in behavioral patterns. The endocrine techniques that are developed will subsequently be utilized as sensitive probes to identify the particular environmental stimuli that influence decision-making in burying beetles. Hormonal manipulations will also be employed to alter male parental behavior in order to examine effects on reproductive success, female parental behavior, costs of maternal care and host selection by a symbiotic phoretic mite. For the first time, this study will integrate hormonal and behavioral analyses of an invertebrate species that exhibits biparental care, infanticide and mate desertion and thus will bring new depth to the study of plasticity of reproductive behavior.
