tell a male and female cardinal apart, as usual the question led me to look at published research on cardinals and their coloration.
One study that I found a little disturbing was done by L. LaReesa Wolfenbarger at Cornell University 1998. They captured 30 male birds with a similar red coloration and 1/3 were given a Clairol Professional “Torch Crimson” treatment to deepen their red color, 1/3 were lightened with an “Ultra Blonde” treatment and 1/3 were left the same color.
A cardinal goes through one full molt in the fall, and their health, and how well they are eating determines how red their plumage will be for the following year. The redder cardinals are usually the more dominant birds.
So what happens if you take cardinals all the same shade of red and make some lighter and some darker? Released the next day after their male beauty treatments, the scientists observed to see if color played a roll in dominance during the non-breeding season.
The results found it didn’t affect their behavior. Birds that are redder naturally are probably in better health, more experienced and better foragers than duller birds and are more dominant naturally. The false redder heads didn’t take advantage of their new coloring to control food resources. Both the falsely brighter and duller birds acted in accordance with their true coloring.
Do you have a question about birds? Send it to email@example.com and I'll do my best to answer it. We also post bird photos every Friday and you are welcome to contribute. Happy birding! Sarah
Source: Is Red Coloration of Male Northern Cardinals Beneficial during the Nonbreeding Season?: A Test of the Status Signaling http://elibrary.unm.edu/sora/Condor/files/issues/v101n03/p0655-p0663.pdf
- What can I feed the cardinals to make them redder? http://bit.ly/vn2HK3
- How to have more colorful birds at your feeder http://bit.ly/rT5Hfj
- Sexually dimorphic Northern Cardinals: Why male and female cardinals are a different color http://bit.ly/ueILUf
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- Types of Bird feathers http://bit.ly/oTXSmm