Unusual sperm morphology in two sedentary songbird species

These data describe the morphology of bird sperm cells. The primary species are white-breasted nuthatch (Sitta carolinensis) and wrentit (Chamaea fasciata), for which we provide data from light microscopy and scanning electron microscopy (SEM). We additionally provide SEM data for Eurasian and Azores bullfinches (Pyrrhula pyrrhula and P. murina). For reproducibility, we provide summarised data on ecological and life history traits. We use that data in phylogenetic analyses to understand the evolution of the unusual sperm shape that is the focus of the paper.  , , , # Data from: Unusual sperm morphology in two sedentary songbird species

[https://doi.org/10.5061/dryad.p8cz8wb1t](https://doi.org/10.5061/dryad.p8cz8wb1t)

## Description of the data and file structure

Our original data are descriptive statistics of sperm morphology from individual male songbirds. Background data on captures are also provided. 

For reproducibility, we also include summaries of otherwise-available data. Because of changing species concepts and names, it may not be straightforward to reproduce our results from the original sources. For purposes other than reproducibility, please go to the original source data. 

### Files and variables

#### File: NuthatchWrentitData.xlsx

**Description:** Morphological measurements of sperm cells from light microscopy and scanning electron microscopy (SEM), with field data.

##### Variables: Most variable names are fully self-contained, including units.

* Sperm measurements collected via light microscopy: Head, µm; Midpiece, µm; Fla...,