an overview of my selection method
Every breeder selects their keepers for breeding on from in different ways, based on what they consider to be priorities and what their personal preferences are. Some use quite rigid tests (these breeders are mostly in the US), but I prefer to strike a balance between my gut, my heart, and my head through observation as the kittens develop.
As my litters grow, I have them out for regular Ďfree rangeí play on a sofa with varying toys and items for them to explore and climb on/in/through/over/under. I observe how they interact with these and each other, and with me. If there are near identical kittens in a litter I will use sharpie pens to put coloured marks on their tails from about 3 or 4 weeks of age, so that I know which kittens are doing what.
Iím looking for rats who are bold, curious, adventurous, and also interested in me. Iím also looking for good type (the shape and size of head, eyes, ears, body, and tail), and a variety that will be useful for the line (for instance, a black kitten from two parents who are both carrying a gene I want, may not even carry the gene, so I would rule them out, but if I am wanting havana, and all the havanas had poor type but there was a chocolate who was better and carried american mink, then Iíd opt for the chocolate over the havana).
Type is not always apparent until kittens are close to homing age, and in the case of silvermanes, their coats canít be fully assessed until their moult is over, so for some litters my decision isnít necessarily made until 8 or even 9 weeks.
Temperament and character are far less easily defined traits, and they unfold over the course of several weeks. Any signs of relative nervousness or bullying behaviour will probably rule a rat out. I like rats who are the first to climb the rope, the ones who get up to the top of the sofa back, the ones who rush to see me when I kneel down at the front but who go off again having said hello, or who climb on me to explore my shoulders or head. When these elements are combined in the same individuals, again and again over the course of time, they will go on my shortlist assuming their type and variety are good enough.
By the time they reach about 6 weeks, I will subject a group of kittens to a loud noise such as a clap, and observe how they react Ė some will flinch and then immediately come forward to see what it was, others may come forwards immediately, but there may be a few who remain still for longer indicating a nature that is too cautious for my liking. Iíll also leave the room for a short while and observe how they react to my return Ė some will be a little startled, but I like the ones who come straight to meet me.
My final decisions will depend on what Iím needing most (if Iím looking at doe keepers, I will probably already have their intended mate, so can balance his strengths or weaknesses against hers), and on how much choice I have. A completely perfect rat is exceedingly rare, but Iíll have in mind a minimum acceptable level, which could be called Ďparí. If there is a rat with perfect type but below par temperament then I wonít keep them, equally if there is a rat with perfect temperament but below par type, I wonít keep them either. In theory, if Iím keeping two of the same sex, then I might favour type for one and temperament for the other, but itís never quite as clinical as it may sound, and Iíll listen to my gut in the end.
The result is an observable improvement (in my opinion) in temperament within only 2 or 3 generations, although type can take longer. And while my keepers will be the best ones, the rest are still fabulous pets.