Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Skip to content

Sex ratio of Western Bluebirds (Sialia mexicana) is mediated by phenology and clutch size (dataset)

Metadata Updated: July 3, 2022

Mothers may produce more of one sex to maximize their fitness if there are differences in the cost of producing each sex or there are differences in their relative reproductive value. We tested if breeding date, clutch size and drought conditions influenced offspring sex ratios in Western Bluebirds (Sialia mexicana) from 1997 to 2017. We found that hatch dates late in the breeding season were associated with the production of more females. When clutch size was taken into account, small clutches yielded significantly more females late in the breeding season compared to the early and middle parts of the breeding season that produced significantly more males. Large clutches early in the season tended to produce more females, although this was not significant. Drought severity was not correlated with sex ratio adjustment. Citation information for this dataset can be found in the EDG's Metadata Reference Information section and's References section.

Access & Use Information

Public: This dataset is intended for public access and use. License: See this page for license information.

Downloads & Resources



Metadata Created Date July 3, 2022
Metadata Updated Date July 3, 2022

Metadata Source

Harvested from EPA ScienceHub

Additional Metadata

Resource Type Dataset
Metadata Created Date July 3, 2022
Metadata Updated Date July 3, 2022
Publisher U.S. Environmental Protection Agency
Data Last Modified 2021-01-15
Public Access Level public
Bureau Code 020:00
Schema Version
Harvest Object Id e62293e5-9882-470d-87a7-32254e45efa4
Harvest Source Id 04b59eaf-ae53-4066-93db-80f2ed0df446
Harvest Source Title EPA ScienceHub
Program Code 020:000
Publisher Hierarchy U.S. Government > U.S. Environmental Protection Agency
Related Documents
Source Datajson Identifier True
Source Hash 7ab113089c77fef70c443143c5e9a1832787ea11
Source Schema Version 1.1

Didn't find what you're looking for? Suggest a dataset here.