Written and published by Grant Donaldson (UK)

 

The Dark factor Blues are the equivalent of the Olive and Dark green mutations previously discussed under Dark factor Greens. The Single dark factor blue is commonly referred to as cobalt, and the double dark factor blue referred to as mauve.

 

 

 

Cobalt Fischer's                                              Mauve Fischer's

 

As with many mutations within the eyering species of Lovebird it is most probable that this mutation was transmutated from another species, most likely the Masked Lovebird, though the breeder should not be put off by this. Dark factor green and blue series Fischer’s are as much a true colour variety as the darkfactor Masked. As long as any one breeder keeps his stock in good order and carefully introduces sensible crosses, his stock will go from strength to strength and any traces of dark marks to the face can be eliminated.

 

The Dark factor blue series birds follow exactly the same incomplete dominant mode of inheritance that the Dark factor greens do and are represented with single factor and double factor birds. Their genetic mode of inheritance is as follows:

 

Blue x Cobalt (SF) = Blues & Cobalts (SF)

 

Cobalt (SF) x Cobalt (SF) = Blues, Cobalts (SF) & Mauves (DF)

 

Cobalt (SF) x Mauve (DF) = Cobalts (SF) & Mauves (DF)

 

Blue x Mauve (DF) = All Cobalts (SF)

 

Mauve (DF) x Mauve (DF) = All Mauve (DF)

 

The above results are regardless of which parent carries the dark factor gene. It should be noted however that it is generally very difficult to breed double dark factor birds with exceptionally good feather quality. Most double dark factor birds have poorer feathers than single dark factor birds. This is not to say that they are not healthy, robust birds. It is just that they are generally not so good for the show bench. For this reason mauve x mauve pairings are best avoided. The best double dark factor birds are always bred from two single dark factor birds.

 

It is this fact that both colours can be produced in the same nest by a pairing of each colour that leads to believe that they are separate mutations, though genetically equivalent of each other.

 

Young cobalt and mauve chicks always hatch with white down. This quickly turns to grey at about the age of ten days. Their eyes and feet are normally coloured and the beak is a light orange colour until about 3 to 4 months old when it turns to the expected coral pink colour of a blue series bird.

 

4 ½ week old Cobalt Fischer’s Lovebird Chicks

 

The dark factor mutation combines well with other mutations, particularly the dilute, edged, violet and pied mutations. There is no point breeding it through Lutino. Dark factor blue dilutes are particularly nice though can take a while to establish from scratch. The easiest way would be to start with a mauve and yellow bird (either dilute yellow or yellow pastel). Their expected offspring would be as follows:

 

Yellow x Mauve (DF) = All Dark green/Blue/Yellow (SF)

 

To the left is one of the authors dilute yellow x mauve proven pairs from which he has bred many fine dark greens/blue/dilute and cobalts/dilute to breed dilute dark factors from. The fact that cobalt chicks have been reared by this pair proves that the dilute cock must be split for blue.

 

Dilute Yellow x Mauve Fischer’s Lovebirds

 

The best way to start this breeding programme would be to run at least two pairs of dilute yellow to mauve in tandem. This way the best young from both pairs can be retained to make unrelated pairs of the resulting double split normal offspring the following year, thus avoiding inbreeding.

 

If two of the double split dark greens/blue/dilute youngsters were bred together the expected results could be expected:

 

Dark green/blue/dilute yellow x Dark green/blue/dilute yellow

= Normals, Dark greens, Olives, Blues, Cobalts,

 

Mauves, Dilutes, Dilute Dark green, Dilute Olive,

 

Dilute Blue, Dilute Cobalt & Dilute Mauve.

 

The list of various split birds is considerably longer. None of the blue, dilute, or green series can be genetically guaranteed as there is no way of telling if the birds are split for blue, split for yellow, split for both or not split at all.

 

It is obvious from the above results that the percentage of dilute dark factor blues will be quite small and that the percentage of genetically unknown birds produced will be high, but any breeding programme relies on the retaining of certain individuals to improve the programme each year. It is this challenge that attracts many bird keepers to breeding mutations.

 

This dilute cobalt Fischer is a good example of a dilute dark factor. This particular bird is paired to a cobalt/dilute which makes a genetically compatible pairing. All the chicks will be blue, dilute blue, cobalt, dilute cobalt, mauve and dilute mauve in varying percentages. The advantage of this pairing is that all the resulting young can be genetically guaranteed, it is known whether they are visually dilute or genetically split dilute. Unlike the pair of dark greens/blue/dilute discussed above there is no way of telling if any one chick is carrying blue or dilute in split form and so can only be sold at face value. Selling a bird as ‘possibly split for blue’ is not much use to a breeder. Cobalt and mauve birds are also extremely useful for breeding other mutations, especially the edged and violet mutations which will be described later.

Dilute Cobalt Fischer’s Lovebird

 

For more information about lovebirds please read our other posts