Crested has been present in pigeons, budgies, and canaries, with distinctive features in each species.
It was never expected that Crested would also be present in Lovebirds. Even on the mutation table, it is listed as a "multi-factorial" mutation. Crested is also present in Agapornis fischeri, but I have not seen it.
The only crested Agapornis I have seen is in Agapornis roseicollis combined with the SL ino mutation.
This phenotype was first recognized in Belgium for Agapornis roseicollis, while fischeri was first recognized in the Philippines.
Then, Italian breeder Lorenzo Bassi also reported having crested PallidIno roseicollis. Meanwhile, in 2022, Tibor Nagy's breeder published the crested Agapornis Roseicollis SL Ino.
Knowing that many breeders have shown ownership of this crested adds to the belief that this mutation is true.
But among the many posts of these lovebird breeders, nothing mentions the fischeri species. If readers have crested Agapornis fischeri, you can email it to me for coverage and inclusion in the article.
Background on the crested mutation in Agapornis roseicollis
The crested Agapornis Roseicollis is caused by a genetic mutation that affects the development of the feathers on the bird's head.
In scientific terms, this mutation occurs in a gene that regulates morphogenesis (body shape formation). In the case of crested, it causes a change in the structure of feather growth in the rear head area.
In ordinary birds, head feathers grow according to a pattern determined by genes that regulate the morphogenesis and differentiation of feather cells. Usually, they grow close to each other.
However, the crested mutation disrupts this typical pattern, resulting in some feathers on the top of the head growing in a different direction than usual, creating a crested effect. This is because the normal feathers collide with some of the feathers that are growing in reverse.
The crested on Agapornis roseicollis looks very simple; indeed, it is due to only a few hairs growing in reverse. This differs from the crested canary, which has a very extreme crest pattern resembling a crown.
Nature of inheritance of crested Agapornis roseicollis At the beginning of its discovery, crested was identified as dominant, inferred from several breeding tests conducted by senior breeder Harry Bens. However, in its development, crested was recognized as an autosomal multi-factorial and officially registered in the mutabase table.
This makes the crested mutation very rare and challenging to develop in captivity. There is no specific formula for its crossing model. Unlike the pied mottle, it is also autosomal multi-factorial, which is often encountered.
Crested cannot be planned with crossing methods such as recessive and dominant mutations. Only luck can give you this phenotype.