Dark Factor in Peachfaced Lovebirds
by Doug Bedwell

Dark Factor (DF) is a mutation which creates many interesting color possibilities. DF is a semi-dominant mutation (sometimes termed partial dominant). This means two things:
1. A bird needs only to inherit the mutation from ONE of its parents to show the effects of the mutation. A bird which carries a single copy of the mutation is referred to as a "single dark factor" bird.
2. A bird which inherits the mutation from BOTH of its parents, referred to as a "double dark factor", will look very different from a single dark factor bird.

Unlike most of the other mutations in the Peachfaced Lovebird, Dark Factor does not effect the bird’s feather pigments in any way. Rather, what is effected is actually the physical structure of the feathers. (Jim Morris, "Notes on the Dark Factor", Agapornis World, Oct. 1980). This subtle change in the feather structure alters way that the feathers reflect light, causing the bird’s color to be both deeper, and darker.

On most peachfaced, the presence of the dark factor is most easily identifiable by checking the color of the bird’s rump. In a normal peachie, the rump will be a bright tourquoise blue. If a single dark factor is present, the rump will be a dark royal or navy blue. Double dark factor birds are easily recognized, as the body is very dark, and the rump is actually grey.

Perhaps the most exciting aspect of the Dark Factor is the tremendous variety of colors it makes possible, when it is combined with other mutations. Almost every other color available in the peachfaced can be produced in three distinct shades by combining it with the dark factor. This has led to many beautiful varieties of peachfaced, but also a wide variety of names for these combinations, which frequently prove confusing to the novice enthusiast. Though most experienced breeders are familiar with terms such as "jade", and "slate" many beginning breeders that I have spoken to have been confused by these terms.

The terms "Jade" traditionally refers to a single dark factor green, while "Olive" would refer to a double dark factor green. "Cobalt" refers to a single dark factor Dutch Blue bird, and "Slate" indicates a double dark factor Blue.

These terms were simple enough when there were only a few mutations of the Peachfaced to deal with, and most experienced breeders still use them informally. However, the generally accepted terms for all single and double factor lovebirds are "Medium" and "Dark", respectively. Thus, "Jade," "Medium Green," and "Single Dark Factor Green" are synonomous. The advantage of the terms "Medium" and "Dark" is that they are both simpler and more precisely descriptive than the older terms. Whereas "cobalt" can only refer to birds in the blue series, and "jade" only to the greens, "medium" can be prepended to any color description to indicate the presence of a single dark factor.

 

 
home madagascar lovebird

green fischer's lovebird

 

Photo credits: whitefaced slate by B&G Birds