American Fancy Rat & Mouse Association

This article is from the WSSF 2012 AFRMA Rat & Mouse Tales news-magazine.

Colors & Coats

Outcome Of Rat Breeding: Berkshire x Berkshire; Berkshire or Irish Rat?

By Karen Robbins

Outcome Of Rat Breeding: Berkshire x Berkshire

Natalie Watson, Facebook
QI’m a little confused about my first litter. My doe is a light Beige Berkshire; the buck is a Dumbo Blue Berkshire. We have no family history of either parents. We were expecting Hooded, Berkshire, and Self babies, probably all Black (but there was a possibility that the mother carried Blue).

Instead, it looks like roughly 50/50 variberk (?) and Self (?). Can someone explain the inheritance of patterns to me? I thought it was HH (Self), Hh (Berkshire), and hh (Hooded), but breeding our two Berkshires produced what appear to be variberks, and I’m confused.

The rats live with my boyfriend in another state right now. My boyfriend tells me some of the ones I thought were self pups apparently have little islands of white on their bellies. I’m not certain if there are any that are completely solid-coated. This is his first rodent litter, and he’s having trouble telling some of the pups apart.

ACan you send photos of the parents (top and bottom views) and of the kids so we can help identify these rats for you?

There are two kinds of Berkshire—Hooded Berkshire (Hh) and Variegated/Dalmatian Berkshire. The Hooded Berkshires when bred together, will indeed produce Self, Berkshire, and Hooded. These rats don’t have a head spot and the white on their belly usually just covers the belly area and they will normally have a colored chest/throat area. The Variegated/Dalmatian Berkshires will have a head spot (can range from a spot to a streak or blaze) and have a lot more white on the underside that includes the complete belly area and chest and are marked more like what you would see in a Tan/Fox mouse having the entire underside a different color.

Variegateds are very common around the country and it sounds like you have this type of Berkshire since you describe variberk as the markings on some of the kids. Breeding two Variegated Berkshire will get you more of the same, breeding a Hooded Berkshire to a Variegated Berkshire will get you some of each which may be what happened in your case.

Sorry we can’t be of more help, but photos are needed to give a more accurate answer.

Berkshire or Irish Rat?

Samantha Hamilton, Facebook
QI was just wondering if someone could help me out on the color of my guy Harley? I’m thinking he is a Black Berkshire or maybe Irish, but he has started to get an almost cinnamon color coming in on his rear.

Black Irish rat

AHe looks like a Black Irish. Berkshires are supposed to have the entire belly, chest, and throat area white with a white star/head spot. They should be marked similar to a Tan/Fox mouse with even demarcation lines between the top color and belly color. But unlike a Tan/Fox mouse which is naturally occurring and you get straight lines, with the rats it is a marking, so you have to select for even edges.

It is common for Blacks to get brown patches as they get older from molting that can take a while sometimes to completely molt out. It is also very common for Black females to turn brown and patchy. It looks like your guy doesn’t have much/any silvering? which is common for males to get. Thanks for taking the photo in natural lighting, it helped with his color ID. *

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July 12, 2015