Data from: Linkage and trade-off in trophic morphology and behavioral performance of birds

1. Bill closing behaviour involves a complex suite of tissue types, kinematics, morphological states and muscle architectural arrangements that has been under the scrutiny of natural selection for millions of years. Hence, an evolutionary shift to specialize in closing force may come at a cost to closing velocity and vice versa. 2. Using field measurements on behavioural performance and morphological data from museum specimens, we tested predictions of the force–velocity trade-off hypothesis in 18 species of North American birds with diverse phylogenetic and ecological backgrounds. 3. Linear models revealed that size and shape are excellent predictors of both bite force and closing velocity. However, taken one at a time, they each have a somewhat unique set of morphological predictors. In-lever length, mandibular depth and bill width comprise the best model of prediction for force, while a combination of out-lever length and total skull length provides the best prediction of closing velocity. Additionally, in our sample, only force is size-dependent. Hence, the predicted trade-off is revealed only after correcting bite force for head size. 4. Various modes of predation and decoupled morphological prediction models for performance suggest that specialization towards one strategy (e.g. increase force) may not necessarily come at a cost to the other. towards one strategy (e.g. increase force) may not necessarily come at a cost to the other

Data for FE-2013-00888.R2

Appendix I. Bill closing velocity for 18 species of North American birds. First columns include: AOU Species Codes, vernacular and latin binomials. Other columns include: BC = bill closing velocity in cm/s (for analyses, I used the maximum value for each individual). Location: 1= Private residence in Pittsburgh, PA (PPA), 2 = Beechwood Farms Nature Reserve (PPA), 3 = North Park Latodami Nature Center (PPA), 4 = Bloomsburg University campus, Bloomsburg, PA, 5 = National Aviary in Pittsburgh, (PPA). Sex, M = Male, F = Female, “.” = unknown. Appendix II. Bite-force for 18 species of North American birds. First columns as in appendix I. Band # = USGS aluminum band number for each individual. Asterisk next to four-letter code denotes bite-force inferred by regression from a larger data set (Corbin, et al. in prep). Recap = recaptured individual; the highest value for captured or recaptured bird was used in analysis. Bite-force (N); these are the calibrated amplifier readings. Location = 1 Bloomsburg University campus, Bloomsburg, PA. 2 = private residence in Orange Township, Columbia County, PA, 3 = taken from a data set on netted birds in Coconino Forest, AZ in 2011 (Corbin, et al. in prep). Appendix III. Skull/jaw morphological measurements for 18 species of North American birds. Measurements are in mm. First columns as Appendix I, M = male, F = female. Museum specimen numbers available upon request from CEC (BAHS, Bloomsburg University, Bloomsburg, PA 17815, [email protected], 570-389-4134