The respiratory system influences flight mechanics in soaring birds
Cite this dataset
Schachner, Emma et al. (2024). The respiratory system influences flight mechanics in soaring birds [Dataset]. Dryad. https://doi.org/10.5061/dryad.0k6djhb64
Abstract
The subpectoral diverticulum (SPD) is an extension of the respiratory system in birds that dives between the primary muscles responsible for flapping the wing. Surveying the pulmonary apparatus in 68 species showed that the SPD was present in virtually all soaring taxa investigated yet absent in non-soarers. We find that this structure independently evolved with soaring flight at least seven times, indicating that the diverticulum may have a functional and adaptive relationship with this flight style. Using the soaring hawks Buteo jamaicensis and B. swainsoni as models, we show that the SPD is not integral for ventilation, that an inflated SPD can increase the moment arm of cranial parts of the pectoralis, and that pectoralis muscle fascicles are significantly shorter in soaring hawks than in non-soaring birds. This coupling of an SPD-mediated increase in pectoralis leverage with force-specialised muscle architecture produces a pneumatic system adapted for the isometric contractile conditions expected in soaring flight. The discovery of a mechanical role for the respiratory system in avian locomotion underscores the functional complexity and heterogeneity of this organ system and suggests that pulmonary diverticula likely have other undiscovered secondary functions. These data provide a mechanistic explanation for the repeated appearance of the SPD in soaring lineages, demonstrating that the respiratory system can be co-opted to provide novel biomechanical solutions to the challenges of flight and thereby influence the evolution of avian volancy.
README: README document for the dataset from: Schachner et al., 2024. The respiratory system influences flight mechanics in soaring birds. Nature. https://doi.org/10.5061/dryad.0k6djhb64
Description of the data and file structure
This dataset includes the files and code used to re-run the character correlation analyses from the manuscript. It also includes the surface files that were used to model the moment arms for the biomechanical analysis of the pectoralis models of the Red-tailed and Swainson’s hawks. These models should be opened and run using GaitSym 2019. The link for this free software is listed below. Lastly, there is a zipped file of high-resolution images (TIFF image files), showing each of the birds scanned for this project. They are the original images used in the extended data section of this manuscript.
The following files are provided:
1) Input files and code necessary to run the character correlation analyses in R.
2) A zipped file with the surfaces used for the MDA models. Each folder contains the MDA model file (.gaitsym) and associated OBJ graphics file for visualization of each bird. Models can be opened in GaitSym2019 available from https://animalsimulation.org. Models will not work with older versions of GaitSym. Avian names match the chart provided in the methods section of the manuscript.
3) A zipped file with the high-resolution images of the axial slices from the Extended Data figures demonstrating the morphology of the subpectoral diverticulum around the sternocoracoideal joint. These TIFF files are exported screen shots of single CT or µCT DICOM images of birds included in the study. The species is listed in the file name.
Sharing/Access information
All data are freely available
Code/Software
The input files and code for the character correlation analysis can be run in R. R is available here: https://www.r-project.org/
The MDA models should be run in GaitSym2019 which is available from https://animalsimulation.org
Funding
University of Florida Gatorade Award Allocation
Louisiana State University Health Sciences Center Research Enhancement Program Fund