This package was developed to compute the center of gravity and moment of inertia tensor of any flying bird. It functions by modeling a bird as a composite structure of simple geometric objects. This requires detailed morphological measurements of bird specimens although those obtained for the associated paper have been included in the package for use. Refer to the vignette and supplementary material for detailed information on the package function.


You can install AvInertia from CRAN via:


Or to get the latest (developmental) version through GitHub, use:



Refer to our vignette for a detailed example.

Contributing and/or raising Issues

Feedback on bugs, improvements, and/or feature requests are all welcome. Please see the Issues templates on GitHub to make a bug fix request or feature request.

To contribute code via a pull request, please consult the Contributing Guide first.


Harvey, C., Baliga, V.B., Wong, J.C.M., Altshuler D.L., and Inman, D.J. Birds can transition between stable and unstable states via wing morphing. Nature 603, 648–653 (2022). https://doi.org/10.1038/s41586-022-04477-8


GPL (>= 3) + file LICENSE