Category Archives: Algemeen

FAQ: Are cross sections the only way to determine colour mutations?

FAQ: Are cross sections of feathers the only way to determine colour mutations?

Absolutely not. Cross sections in combination with a light microscope give us only the basic information on what type of mutation we probably have:

  • Melanin mutations: Leucism? Albinism? Dilution?
  • Change of feathers structure / keratin layer?
  • Other pigmentation?
  • ……

For further research we need other, more specific tools.
Here is a list of recommended scientific instruments / methods needed to:

Impairment of mixed melanin-based pigmentation in parrots

Parrots and allies (Order Psittaciformes) have evolved an exclusive capacity to synthesize polyene pigments called psittacofulvins at feather follicles, which allows them to produce a striking diversity of pigmentation phenotypes. Melanins are polymers constituting the most abundant pigments in animals, and the sulphurated form (pheomelanin) produces colors that are similar to those produced by psittacofulvins. However, the differential contribution of these pigments to psittaciform phenotypic diversity has not been investigated. Given the color redundancy, and physiological limitations associated to pheomelanin synthesis, we hypothesized that the latter would be avoided by psittaciform birds. Here we test this by using Raman spectroscopy to identify pigments in feathers exhibiting colors suspicious of being produced by pheomelanin (i.e., dull red, yellow and grey- and green-brownish) in 26 species from the three main lineages of Psittaciformes. We detected the non-sulphurated melanin form (eumelanin) in black, grey and brown plumage patches, and psittacofulvins in red, yellow and green patches, but no evidence of pheomelanin. As natural melanins are assumed to be composed of eumelanin and pheomelanin in varying ratios, our results represent the first report of impairment of mixed melanin-based pigmentation in animals. Given that psittaciforms also avoid the uptake of circulating carotenoid pigments, these birds seem to have evolved a capacity to avoid functional redundancy between pigments, likely by regulating follicular gene expression. Ours study provides the first vibrational characterization of different psittacofulvin-based colors and thus helps to determine the relative polyene chain length in these pigments, which is related to their antireductant protection activity.

Neves, Ana Carolina de Oliveira, Ismael Galván, Dirk Van den Abeele. 2020. “Impairment of Mixed Melanin-Based Pigmentation in Parrots”. Journal of Experimental Biology.

On request: article Agapornis roseicollis: DM Jade

New mutation in Agapornis roseicollis: DM Jade
(Article published in 2017 / update 2018)

By Dirk Van den Abeele
Ornitho-Genetics VZW
MUTAVI, Research & Advice Group

It has been nearly ten years since Miriam Bisiacchi told me she had a deviating colour in a number of her Agapornis roseicollis. These birds had all been born with red eyes which became darker after a few days, but the main problem was that all these birds also contained the marbled factor. The consequence of course was that it was difficult to predict what this deviating factor actually does. Of course, we always recommended Miriam, as always, to try to breed this mutation in the green base type. That is the only way to determine what this mutation entails.

Asteriornis maastrichtensis

Amateur paleontologist Mr. Maarten van Dinther discovered in 2000, near the Dutch border in Belgium a fossil from probably one of the oldest – extinct – birds (known till now). Recent research at the University from Cambridge revealed that this bird lived in the Cretaceous period, that was 66.8–66.7 million years ago and they named it Asteriornis maastrichtensis. The bird was a mix of galliform (landfowl)-like and anseriform (waterfowl)-like features. Due to this, some name it the wonder chicken. Interesting to know is that this animal lived at the same period of Tyranosaurus rex.

The ‘wonderchicken’ fossil from Belgium reveals dawn of modern birds


Field, Daniel J., Juan Benito, Albert Chen, John WM Jagt, en Daniel T. Ksepka. 2020. “Late Cretaceous neornithine from Europe illuminates the origins of crown birds”. Nature 579(7799):397–401.

Archive articles

The last weeks we spend some time to our online archive ( and we were able to complete the list with my articles that have been published in:
• Alcedo Edizioni Srl
• AOB Belgium
• Arndt Verlag
• Avizandum South Africa,
• BVA-International
• BVP Belgium
• CDE France (list not complete)
• €uro-Parrot
• Kelsey Media UK
• Nederlandse ForpussenClub,
• Papousci – Czech parrot magazine
• Parkietenfederatie (list not complete)
• Parkieten Sociëteit
• Roma Press SA – Spain
• Onze Parkieten – The Netherlands
• KBOF – Belgium

We had a complete database with all these articles, but due a PC crash a few years ago, we lost the data from our articles published in:

ANBvV – The Netherlands
NBVV – The Netherlands
PSC – Parkieten speciaal club
Australian Bird Keeper
and an Hungarian magazine –  name unknow

Now we are trying to recover this data and to complete the list.

Hans Kater is coordinating this project, if you have these magazines in your library – or you are aware of other magazines – and you are willing to help us,  please contact Hans via


UPDATE: Measures related to the corona crisis

Due to the corona crisis, we are forced to cancel all our meetings, courses and lectures in Europe until September 1.

Meetings, courses and lectures outside Europe are cancelled until January 1. 2021.

Webinars and online meetings continue as usual.

Each organizer will be notified personally.


New url

As of today, we have an new url for our website:

the url “” will expire soon.

Attention: the email address no longer exists

Data cursusdagen

Ten gevolge van de coronacrisis waren we genoodzaakt om de lessen 2, 3, 4 en 5 te verplaatsen naar later datum. Deze lessen gaan nu terug door op zaterdag 5 september, zaterdag 19 september, zaterdag 3 oktober en zaterdag 10 oktober.

Grey Forpus coelestis

We recently concluded our investigation into the AR grey factor at Forpus coelestis. An article about this mutant will, in the first instance, be published by AOB Belgium and the Dutch forpus society.

Next step is to compare this mutation with the grey factor in Agapornis roseicollis.

FAQ: Combinations of alleles of the same gene

FAQ: Combinations of alleles of the same gene are indicated by writing the mutant names one after the other, for example PastelIno. A capital is used to indicate the start of each mutants name.

But how do we write the name of a combination with epistatic genes?

Well here we have an  easy answer: exactly the same as we write alleles of the same gene! The mutant (gene) names one after the other. Why? It are also two (different) alleles that are creating a (non wild type) phenotype.

Visitors in 2019

This year we had a total of 197.361 visitors – from 141 countries – on our website (stats 1th of January till 28th of December 2019)

These countries are in the top 20:

Belgium 31656
Netherlands 23667
Indonesia 21051
Philippines 16143
Pakistan 15897
India 13566
United States 10653
South Africa 6048
Spain 4179
Portugal 3591
Germany 3387
Italy 2982
France 2787
Singapore 2628
Brazil 2481
United Kingdom 2388
Thailand 2298
Australia 2229
Egypt 1956
Canada 1593

Thank you all for your visits and support!

Agapornis fischeri blue2

The last months we received several reports from breeders who bred blue2 Agapornis fischeri which develop a yellow / pinkish forehead. We suspect that this (as I mentioned in my article about blue and blue2), can confirm our thesis that blue2 types probably still have the possibility to produce (a limited amount of) psittacin.
The link between * sapphire * and blue2 becomes also more likely. Hopefully we will be able to prove or counterprove this theory in the future by DNA analyses.