Inbreeding and kinship
The app can warn you when two birds have known kinship before creating a pair. The warning does not stop you breeding them: it gives you information so you can decide with better judgement.
How it works
Detection uses the family tree you have recorded in each bird's profile. The more fathers, mothers and generations you have filled in, the better the app can detect kinship.
If information is missing from the tree, the app does not invent relationships. In that case it may show no warning even though real kinship exists outside the saved data.
Review levels
In Settings → Breeding and reproduction you can choose the inbreeding level you want to review. When you select a level, the app shows its legend so you know which relationships it includes.
The levels decide how far the app should look:
- Level 1: very close relations, such as parents and children or siblings.
- Level 2: wider close relations, such as uncle/niece, aunt/nephew, grandparent/grandchild and first cousins.
- Higher levels: broader checks for common ancestors when the family tree allows it.
You can also turn Warn about related pairs on or off without changing the selected level.
When creating a pair
When you choose the male and the female, the app checks their kinship according to the configured level. If it finds a relationship, it shows a warning before saving.
The warning is informative. You can cancel, review the profiles or carry on if you decide the cross is acceptable in your case.
When putting a bird in a breeding cage
Since 6.4.3 the warning also fires when moving a bird into a cage in breeding use (a breeding-type cage, one labelled as breeding or, with no label, one with an active pair or a nest): the app compares the bird with the opposite-sex birds already inside, with the same review level and the same declared kinships, and shows you which are relatives and their expected inbreeding. A warning, not a block. Aviaries labelled as moult, weaning, rest or quarantine are left out: siblings live together there on purpose. See Cages.
Inbreeding percentage
Besides the warning, the app calculates two percentages to interpret the cross:
- Expected inbreeding in the offspring (F): chance that the offspring inherit identical genes from the parents' kinship.
- Relationship between the parents (R): how genetically similar the male and female are.
For reference: full-sibling parents, or father × daughter, give offspring with F ≈ 25 %; first cousins, F ≈ 6.25 %.
The app distinguishes full siblings from half siblings. Two birds with the same father and the same mother are full siblings. If they share only father or only mother, they are half siblings and the expected inbreeding is lower: usually F ≈ 12.5 % instead of F ≈ 25 %.
A colour traffic light sums up the level: Low, Watch, Notable or Discouraged. You see these figures when creating or editing a pair, on the pair page, in the pairs list and in the Inbreeding tab of the Genetic Calculator.
The family tree and its PDF also show this difference, so full siblings are not confused with half siblings.
The percentage depends on the recorded tree: if parents are missing it may fall short. If the app says the tree is incomplete, raise the review level to check more generations.
Recommendations
To make the warnings useful:
- fill in father and mother whenever you know them;
- register chicks from their clutches whenever possible;
- review past pairs if you are unsure about a relationship;
- use wider levels if you work with closed family lines.
Inbreeding does not always mean an immediate problem, but it is worth seeing it before forming the pair.
Setting relationships
From a bird's profile, under Genealogy, you have Add relationship (or Manage relationships if there are already some). The editor shows:
- Parents: choose the father and mother among your birds.
- Grandparents: four slots, paternal and maternal. If the intermediate parent is registered, tapping a slot assigns the grandparent directly to the tree; otherwise the app offers to assign the parent first or to declare the grandparent without a tree.
- Siblings: full, through the father, through the mother, or "I don't know which parents they share".
- Other kinships: the uncles, cousins, nephews and grandchildren the tree proves, plus the ones you declare. With Add relationship you can also record great-grandparents, great-grandchildren, uncles, nephews, cousins and grandchildren; and with Other kinship… any relationship by degrees: you set how many generations separate each bird from their common ancestor (great-uncle = 1 and 3; second cousins = 3 and 3; great-great-grandparent = 0 and 4) and the app shows the resulting name before saving.
Whatever the tree can prove is not stored separately: it is computed from the parents, so it never goes stale and no fictitious record fills the tree. Whatever the tree cannot prove is stored as a declared kinship and marked as such everywhere. Every relative derived from a declaration carries an info button explaining which declaration it comes from.
Two sisters bought without knowing their parents
A common case: you buy two hens you know are sisters, but you have no records of their parents. Register each one separately —the Save and add relationship button takes you straight to the editor—, open Add relationship → Add sibling and select the other one. Keep "Siblings; parents not recorded" (or state whether they are full or half sisters, if you know) and save.
The bond appears on both profiles, in the tree, in the PDF and in the inbreeding warnings, marked as Declared. Until you register their parents, the app warns but does not compute a percentage: that would be making up a number from an incomplete tree.
Offspring inherit declared kinships
Following the example: if Perla and Coral are declared sisters and Perla has a chick, Coral automatically appears as that chick's aunt, and the chicks of both as cousins through the maternal line — with nothing else to record, also for future hatchings. If one day you try to pair two of those cousins, the inbreeding warning fires on its own.
The rule is "one declaration per path": the app derives kinships crossing at most one declaration; the rest of the path must be proven by the tree. The declared sister of a bird's declared sister produces nothing, because chaining declarations could fabricate false kinships (two half-sibling bonds on different sides share nobody). If you know that bond also exists, declare it directly.
When the tree catches up with the declaration
If you later register the real parents and the tree comes to prove a declared kinship, the declaration is removed automatically: the relationship switches from "Declared" to "Through parents" and the warnings start computing its real percentage.
Kinships proposed by a hybrid's lineage
When you declare the ancestors without a record of a hybrid (see Birds → Hybridisation) and a bird from your aviary appears in that chain, the app creates the matching kinship on its own —grandparent, great-grandparent or whatever degree applies, with its paternal or maternal branch— and uses it like any other in the inbreeding warnings.
Those kinships stay in step with the lineage: change the chain and they adjust; remove that ancestor and they go. Deleting them from this screen warns you that they will also leave the lineage and that the bird's generation will be recomputed. And if you correct them by hand —"it is actually its uncle"—, your correction wins: the app does not undo it on its own.