Euwing and Misty are autosomal dominant incomplete mutations and Greywing is sex-linked dominant (per OGVZW) in Fischer's lovebirds. One copy (Single Factor, SF) already shows; two copies (Double Factor, DF) show more strongly. There is no "split" for these mutations - if the gene is present, you can see it. For Euwing and Misty, SF × SF = 25% DF, 50% SF, 25% normal, and the fastest route to DF is DF × SF = 50% DF. Greywing is sex-linked, so its outcomes have to be read by sex.
Following Ornitho-Genetics VZW (Dirk Van den Abeele) test-mating and feather research, Greywing in Fischer's lovebirds is sex-linked incomplete dominant, not autosomal. The first birds were reported in the Netherlands in 2009-2010, and OGVZW's feather cross-sections matched the SL dominant greywing of the lineolated parakeet (Bolborhynchus lineola), so the official suggested name is SL dominant greywing. It is not the same mutation as the autosomal dominant edged Fischer's, which it was historically confused with. Practical effect: a Greywing hen paired to a normal male produces greywing sons only and normal daughters, while a Greywing SF cock gives half his daughters single-dose visuals, and a DF cock gives all of them. Euwing and Misty remain autosomal dominant incomplete. Sources: OGVZW: SL dominant greywing in A. fischeri and OGVZW: feather research results. The calculator has been updated to model Greywing sex-linked.
What do SF and DF mean in lovebirds?
SF means Single Factor (one copy of the gene) and DF means Double Factor (two copies). Euwing and Misty are autosomal dominant incomplete and Greywing is sex-linked dominant, so a single copy already produces a visible effect, and two copies produce a stronger version of that same effect. This is why a bird can never be "split" for these mutations: if it carries the gene, you can see it.
Almost every mutation breeders work with is recessive (Ino, Aqua, Dilute, the Fallows) or sex-linked (Opaline, Cinnamon, Pale, plus the not-yet-confirmed pallid phenotype). In both cases a bird can carry the gene invisibly as a split, and you need two copies, or the right sex chromosome, before anything shows. Dominant incomplete mutations break that pattern entirely.
"Incomplete" is the key word. In full dominance, one copy and two copies look identical. Here they do not: SF shows the effect, and DF shows it more strongly. That intermediate step is what makes these three mutations both easy to track and easy to model wrongly.
You never have to test-breed for Euwing, Greywing or Misty. There is no hidden split to chase. Look at the bird: if the effect is absent, the gene is absent. That alone makes these the most predictable mutations in your aviary.
Euwing vs Greywing vs Misty: how they differ
Euwing and Misty are autosomal dominant incomplete and share identical SF/DF percentages. Greywing is sex-linked incomplete dominant, so its outcomes must be read by sex. They differ in what they change too: Euwing alters the wing pattern, Greywing softens the wing melanin to grey, and Misty mutes and deepens the overall body tone.
Euwing and Misty share the same autosomal dominant incomplete inheritance, so every pairing table below applies equally to Misty. Swap the mutation name and the percentages do not change. Greywing does not transfer, because it is sex-linked, and its outcomes are set out separately in the sex-split table further down.
All SF/DF pairing outcomes (engine-verified)
Every percentage below comes straight from the Lovebird Genetics calculator engine. These four combinations are the complete set, there are no others.
| 1.0 Euwing SF × 0.1 Normal | |
|---|---|
| Offspring | Chance |
| Euwing SF | 50% |
| Normal (no Euwing) | 50% |
| 1.0 Euwing SF × 0.1 Euwing SF | |
|---|---|
| Offspring | Chance |
| Euwing DF | 25% |
| Euwing SF | 50% |
| Normal (no Euwing) | 25% |
| 1.0 Euwing DF × 0.1 Normal | |
|---|---|
| Offspring | Chance |
| Euwing SF | 100% |
| 1.0 Euwing DF × 0.1 Euwing SF | |
|---|---|
| Offspring | Chance |
| Euwing DF | 50% |
| Euwing SF | 50% |
Greywing pairing outcomes, read by sex
Greywing is sex-linked incomplete dominant, so the four tables above do not transfer to it. A Greywing cock can be SF or DF because he carries two Z chromosomes. A Greywing hen has a single Z, so she carries a single dose only and can never be DF. Every Greywing pairing has to be read separately for sons and daughters.
| Greywing, sex-linked incomplete dominant | ||
|---|---|---|
| Pairing (cock × hen) | Sons | Daughters |
| Normal cock × Greywing hen | 100% SF Greywing | 100% normal |
| SF Greywing cock × normal hen | 50% SF Greywing, 50% normal | 50% Greywing, 50% normal |
| DF Greywing cock × normal hen | 100% SF Greywing | 100% Greywing |
| SF Greywing cock × Greywing hen | 50% DF Greywing, 50% SF Greywing | 50% Greywing, 50% normal |
How do you breed a Double Factor lovebird?
Pair DF × SF for 50% Double Factor, the most efficient route once you own a DF bird. If you only have SF birds, SF × SF gives 25% DF, and it is the only way to create your first DF from scratch. DF × Normal gives zero DF - every chick gets exactly one copy and comes out Single Factor.
That last one catches people out. It feels like a Double Factor parent should produce Double Factor chicks, but a DF bird has two copies and passes only one. The other parent contributes none. Every chick therefore lands on exactly one copy: 100% Single Factor, guaranteed, no exceptions.
It also means DF × Normal is the perfect way to spread the mutation through your aviary. Every single chick carries it visibly, nothing is wasted, and you can pair those SF birds together later to get your DF birds back.
Why most calculators get these three wrong
Most older calculators were built for recessive and sex-linked mutations only. They either omit Euwing, Greywing and Misty entirely, or model them as simple recessives with a visual/split distinction, which produces wrong percentages. Dominant incomplete inheritance needs separate SF and DF states, not visual and split.
The tell is simple. If a calculator offers you "split Euwing" as an option, it is modelling the mutation incorrectly, because a split Euwing cannot exist. If it cannot distinguish SF from DF at all, it cannot produce the 25/50/25 outcome that SF × SF actually gives.
The Lovebird Genetics calculator models all four SF/DF combinations correctly for Euwing and Misty, and it models Greywing separately as sex-linked dominant, splitting the outcome between sons and daughters. That is why its outcomes for these three differ from tools that treat them as recessive. You can verify any of the tables above by opening the pairing yourself.
Common mistakes with dominant mutations
Looking for splits that do not exist. There is no split Euwing, split Greywing or split Misty. Breeders waste seasons test-pairing normal-looking birds hoping to reveal a hidden dominant. If you cannot see it, it is not there.
Expecting DF chicks from a DF parent paired to a normal. That cross gives 100% SF and zero DF. To get DF you need both parents carrying at least one copy.
Forgetting the 25% normals. Two visible SF parents still throw 25% chicks with no Euwing at all. Those birds are genetically clean and cannot pass it on, no matter how good their parents looked.
Assuming DF is always the goal. DF shows a stronger effect, but in some lines the doubled expression is less attractive than a clean SF. Decide what you are breeding toward before you chase DF for its own sake.
References
- Van den Abeele, D. (2016). Lovebird Compendium. Ornitho-Media. ISBN 978-90-822990-0-3.
- Ornitho-Genetics VZW. Mutations in Agapornis. Accessed 2026.
- BirdLife International. Agapornis fischeri, Fischer's Lovebird. BirdLife Species Factsheet. Accessed 2026.
Euwing pairing outcomes, cock × hen
Breeders usually describe a pairing as cock × hen. Below is every common Euwing pairing written that way, with the exact percentages this calculator produces.
What do you get from a single factor Euwing cock x normal hen?
Half the chicks show Euwing as single factor and half are completely normal. Euwing is dominant, so there is no split form: a bird either shows it or does not carry it.
| Chicks | Outcome |
|---|---|
| All chicks | 50% SF Euwing, 50% normal |
What do you get from a single factor Euwing cock x single factor Euwing hen?
One quarter of the chicks are double factor Euwing, half are single factor and one quarter are normal. Double factor birds show the effect more strongly.
| Chicks | Outcome |
|---|---|
| All chicks | 25% DF Euwing, 50% SF Euwing, 25% normal |
What do you get from a double factor Euwing cock x normal hen?
Every chick is a single factor Euwing. A double factor parent passes one copy to every chick, so no normal chicks are possible.
| Chicks | Outcome |
|---|---|
| All chicks | 100% SF Euwing |
Run any of these in the lovebird genetics calculator to see the full offspring list for your own birds.
Frequently asked questions
What does SF and DF mean in lovebirds?
SF is Single Factor (one copy of the gene) and DF is Double Factor (two copies). Euwing and Misty are autosomal dominant incomplete and Greywing is sex-linked dominant, so one copy already shows visibly and two copies show more strongly. This is why no bird can be "split" for these mutations, if it carries the gene at all you can see it.
Is Euwing dominant or recessive in lovebirds?
Dominant incomplete, not recessive. One copy shows (SF), two copies show more strongly (DF). It is autosomal, so males and females carry and show it equally, and it can never hide as a split.
What offspring does Euwing SF x Euwing SF produce?
25% Euwing DF, 50% Euwing SF, and 25% normal with no Euwing gene at all. It is the only pairing that creates a DF bird from two SF parents, and the 25% normals surprise breeders who assume two visible parents must pass it to every chick.
How do you breed Double Factor Euwing lovebirds?
DF × SF gives 50% DF, the fastest route. SF × SF gives 25% DF and is how you make your first one. DF × Normal gives 100% SF and zero DF, because each chick inherits exactly one copy.
What is the difference between Euwing, Greywing and Misty?
Euwing and Misty share autosomal dominant incomplete inheritance, while Greywing is sex-linked dominant (OGVZW-confirmed), all with SF/DF in males, so the same pairing percentages apply to all three. They differ in effect: Euwing alters the wing pattern, Greywing softens wing melanin to grey, and Misty mutes and deepens the body tone.
Can a lovebird be split for Greywing or Misty?
No, neither has a split form. Misty is autosomal dominant incomplete. Greywing is sex-linked dominant incomplete, so a Greywing cock can be SF or DF and a Greywing hen carries a single dose only. In both cases a single copy is always visible, so if a bird shows no effect it carries no copy and cannot pass it on.
Why do most lovebird genetics calculators get Euwing wrong?
Most older calculators were built around recessive and sex-linked mutations only, and they either omit autosomal dominant incomplete mutations entirely or model them as simple recessives, which produces wrong percentages. Dominant incomplete inheritance needs separate SF and DF states rather than a visual/split distinction. The Lovebird Genetics calculator models all four SF/DF combinations correctly for Euwing and Misty (Normal x SF, Normal x DF, SF x SF, DF x SF), and it models Greywing on a separate sex-linked dominant basis that splits the outcome between sons and daughters. That is why its Euwing, Greywing and Misty outcomes differ from tools that treat them as recessive.