AFRMA - Colors & Coats - Two-Tone Mouse; Mouse Changing Color

This article is from the WSSF 2017 AFRMA Rat & Mouse Tales news-magazine.

Colors & Coats

Two-Tone Mouse; Mouse Changing Color

By Karen Robbins

Two-Tone Mouse

Sarah Kafel, Facebook
Q Anyone know what this coloration would be called? These guys started showing up. At first I thought they had gotten wet, but then Two-Tone Mouse realized their fur was dry. This appears to be genetic, as these have been producing offspring with the same two-tone coloration. Pretty neat, but not sure if this is a recognized color? Thanks for any help.

A Very interesting! My first thought is it is molting. Mice can go through many variations when losing their old coat/getting a new coat from having odd stripes and spots to being half and half like this mouse. However, when molting, they eventually lose their odd molting patterns (sometimes takes weeks) so you know it is from a coat change and not permanent.

You say they have been producing offspring with this two-tone pattern. At what age can you tell they are going to be this? Does the amount on either half vary or are they all pretty much 50/50? Do they only come in this color? Looks like Agouti on the front half and Cinnamon on the back half. Would love to see more photos of various ages!

A 4-month-old Pearl female mouse with dark/light spot and dark rump molt pattern, owned and bred by Karen Robbins, Karen’s Kritters. It is common for these types of molts to take a while to finish. Photo ©2017 Karen Robbins.

A 4-week-old Seal Point Siamese male mouse with spectacles on his face of new color coming in, owned and bred by Karen Robbins, Karen’s Kritters. This type of coat change happens fast. Photo ©2014 Karen Robbins.

Here the whole litter of the 3-month-old Silver Chocolate mice (2 females and male on right) have half and half molt patterns (the male’s isn’t as noticeable. They were nicely silvered, like the front half of their bodies, in the nest, then lost most of the silvering. Mice owned and bred by Karen Robbins, Karen’s Kritters. Photo ©2017 Karen Robbins.

Mouse Changing Color

Katherine Brown, e-mail
Q I was wondering why my mock chocolate male tan mouse is now changing color? His head is turning a more dark chocolate color up to his shoulders, but the rest of his body is his original light mock chocolate. Why is this happening? Should I be worried? Will he turn into this new color?

Original photo of Chocolate poor-Tan male. Photo from Katharine Brown.

Photo sent with this question. Photo from Katharine Brown.

A The photos you sent originally vs. now look like two different mice. If this is the original mouse, then he is a Chocolate Tan (not mock). If this is a new mouse, the color in the photo looks like he is a Beige Fox (belly color will be white with no orange/cream on the edges like a poor Tan may have; Tans have an orange color and may have darker color on the edges and lighter in the middle; to make a Beige Fox, the Beige gene [c^e] changes the orange color of Tan bellies to white but they are still genetically the tan [a^t] gene). If all of the photos are of the same mouse, then that is why giving a proper ID from photos is so difficult as lighting, angle, flash, etc., can make the animals look different or the same when in reality they are not. Getting an ID in person is always the best.

In the current photo it looks like he is molting and should be changed over to all the new color shortly. Nothing to worry about, just sometimes you can see them molting into the new color because of the difference in colors where other times you won’t see this because the old and new colors are the same.

Update: You were right about my male molting. He’s OK, I guess it might have been the weather change or age.

April 15, 2019