Genetic Diversity

Genetic diversity is important to keep any species healthy. Pedigree research is an important tool to monitor this. This page informs you about some aspects of the genetic diversity of the Maine Coon breed.

Top 5 Foundation Cats of the Maine Coon

The Maine Coon breed is founded on more than hundred foundation cats.
However if you look at the pedigrees of the Maine Coons we see in the show
halls today, most of them are founded for 65% - 75% on the same five
foundation cats. We call these five foundations cats, which are most
prevalent in today's Maine Coon pedigrees, Top 5 cats.

The Top 5 of the Maine Coon foundation cats are:

  1. Andy Katt of Heidi Ho
  2. Bridget Katt of Heidi Ho
  3. Dauphin de France of Tati-Tan
  4. Tatiana of Tati-Tan
  5. Smokie Joe of Whittemore


In 1978 Heidi Ho Sonkey Bill was born, a grand son and double great grand son
of Andy and Bridget Katt of Heidi Ho. When bred to Tanstaafl Polly Adeline the
amazing thing was that their offspring all looked alike, almost like clones...
So when we nowadays speak of "clones" we are talking about the sons and
daughters of Sonkey and Polly.
The significance of the clones is, that they were used over and over, because
they threw nice show quality cats and really added size. So many breeders
decided that if a little was good, a lot was better.
So although the clones themselves did not have a very high inbreeding
coefficient (9.4%), there was done a lot of linebreeding with them and their
Nowadays many Maine Coons have pedigrees with 35% clones, sometimes even up to
50% clones.

Coefficient of Inbreeding (COI)

The amount of inbreeding is expressed in percentages. Here at Tricks and Tails
we calculate them for 10 generations of the pedigree. The more generations,
the higher the percentage will be. However if you only calculate only for 4 or 5
generations, like some breeders do, you will get a much lower and less
valuable percentage.

To give you some idea of the meaning of these percentages, we give you a few

25.0% COI, for example mating of brother  to  sister
cat  to  parent
12.5% COI, for example mating of half brother  to  half sister
cat  to  grandparent

Note: The numbers mentioned above are for total outcross pedigrees, when you
linebreed Maine Coons today the percentages will be even higher!

We have seen pedigrees of today's Maine Coons with Inbreeding Coefficients
as high as 25% and even 37%!

Today's Pedigrees

This brings us to today's pedigree, which often shows 35% clones, 70% Top 5 cats
and an Inbreeding Coefficient of 15%.
These kind of pedigrees do not make our Maine Coon gene pool as varied as it
could be. And the more variation there is in the pedigree, the better the
immune system of the cat will be.

Tricks and Tails Pedigrees

Our goal is to breed cats that have pedigrees with less than 25% clones and
less than 65% Top 5 cats and that have an Inbreeding Coefficient below 12.5%.

Analysis of our Breeding Cats

The analysis of our breeding cats has moved. It can now be found at the bottom of the cats' personal page.

For more information visit:

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