This article is from the Jan/Feb 1996 AFRMA Rat & Mouse Tales news-magazine.
By Nichole Royer
This was one of the first mutations from Agouti ever found as it occurs naturally in the wild population with some frequency. Domesticated Black rats certainly predate the rat fancy, and at the very first show for fancy rats (Aylesbury Town Show, October 24, 1901) Best In Show was a Black and White Even Marked owned by Miss Mary Douglas. The Black has been in the standards since the beginning of the fancy and has continued down to the present virtually unchanged.
The only thing that distinguishes Black from the wild Agouti color is that it lacks the band of yellow on each hair. Instead, each hair is a solid color throughout. The AFRMA standard describes the ideal Black as “color is a good solid black throughout, showing no rustiness or white hairs. Eye color is black.” A really excellent Black will have a solid, unsilvered color over the entire body with dark feet all the way to the ends of the toes and good dark pigment on the ears and tail.
The genetics of the Black Self are very simple. The Agouti locus has 2 alleles, “A” Agouti (banded hairs), and “a” non-Agouti (selfs). The only difference between Black and Agouti animals is that Blacks are “aa” and Agoutis are “AA” or “Aa.” Blacks are recessive to Agouti group animals, but dominant to all other colors. Because Black is recessive to Agouti, if bred to an agouti-group animal (Agouti, Blue Agouti, Silver Fawn, Fawn, Lynx, etc.), you will get all agouti-group babies (unless the agouti is carrying black). If a Black is bred to any other non-Agouti color you will get some Blacks, and out of Blacks you can potentially produce any non-Agouti group color.
When breeding Blacks it is important to select against rustiness, silvering, and white feet. No Black should appear gray from silvering, but often youngsters won’t show this fault until they are over 8 weeks old, so this is a variety to select at as old an age as possible. The best combinations to use when breeding for Blacks are Black x Black and Black x dark Agouti, although one of the best I have seen is out of a Lilac. Blacks are often used to improve the points in Siamese, and consequently a number of excess Blacks are produced. Unfortunately, these usually have a considerable amount of silvering, as do most Blacks produced from attempts to improve other colors. The trick to breeding really good Blacks seems to be breeding just for Black, as very few show quality animals are produced out of breeding for other colors.
Blacks are an excellent choice for a novice to show. There are quite a few out there and picking up a fairly good one at a reasonable price should not be too difficult. The faults on Blacks are easily seen, white feet and silvering being the most prominent. Females are the better show animals as the males tend to silver; however, some females (fewer males) will turn brown. This can be either due to age, molt, or sunburning. There is nothing that can be done for a Black who naturally turns brown from age or due to molting, however sunlight will often cause a Black animal’s coat to turn reddish brown. This can be eliminated by limiting the amount of sunlight reaching the animal.
Blacks require little preparation for a show unless they are really dirty, just a wipe with a soft cloth to eliminate any dust just prior to being placed on the judge’s table. If one is really dirty, it can be bathed, but make sure the coat has at least a week to regain its oils, otherwise it will appear dull. There are a lot of Blacks around, including some really good ones. Even the best Black must also have excellent conformation to compete with some of the flashier and less abundant colors; however, an animal which combines both these traits is very attractive.