Euwing, Greywing and Misty are autosomal dominant incomplete mutations 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. All three follow identical inheritance, so the same percentages apply to each: SF × SF = 25% DF, 50% SF, 25% normal. The fastest route to DF is DF × SF = 50% DF.
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, Greywing and Misty are autosomal dominant incomplete, 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, Pallid). 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
All three are autosomal dominant incomplete and share identical inheritance, so the same SF/DF percentages apply to each. They differ only in what they change: Euwing alters the wing pattern, Greywing softens the wing melanin to grey, and Misty mutes and deepens the overall body tone.
Because the inheritance is identical across all three, every pairing table below applies equally to Greywing and Misty. Swap the mutation name and the percentages do not change. That is unusual, and it is genuinely useful: learn the pattern once and you can plan all three.
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% |
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, Greywing and Misty, which 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.
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, Greywing and Misty are autosomal dominant incomplete, 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?
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 does Euwing SF × 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 I breed Double Factor Euwing?
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?
Their inheritance is identical (all autosomal dominant incomplete with SF/DF), 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. Splits only exist for recessive and sex-linked mutations. Greywing and Misty are dominant incomplete, so a single copy is always visible. If a bird shows no effect, it carries no copy and cannot pass it on.