I picked up my 1st Marans Sat. at a swap. 2 black copper, 1 blue copper, 1 splash, straight run. I also picked up 4 Amerecaunas that are about a yr old and already laying and am hoping to find a Marans rooster to breed them to so I can get olive egger babies out of them. It's really hard finding people willing to sell adult birds, everything's a baby chick adn then I have to wait until some time mid-late fall to even start getting eggs in the first place, and then another 6-8 mos after that before those ones start laying. Sheesh! Long process! LOL!
Congratulations on your new birds!
I can't speak for all Marans breeders, but I can speak from my own experience and why adult birds, mostly females, are so hard to get from time to time. For me, there are a couple reasons it's particularly hard to let the pullets go. Until I see what they produce by way of egg color (after all we are talking Marans here and egg color is one of the most important characteristics of the Marans that makes them special) I like to watch how they grow out and mature. This several months gives me time to study them and make notes of which one/s have the best qualities that would help in my next generational breedings.
This time also gives me an opportunity to cull for faults or things that I dislike that I do not want to breed forward in my program. After they begin laying and eggs are suitable for hatching, I like to do some test matings of birds that I have my eye on to see what they might produce, sometimes this can be time consuming, waiting time for cleaning out the hens from rooster to rooster, waiting for the girls to get over being disgruntled about a new rooster in their pen and start laying again. Some hens can be finicky about small changes in their coops and routines and take a short break from laying, once they feel things are settled they resume.
That said....it may take a up to a year or more before I will sell any adults birds that I have, infact, the majority of the time the average ages of adult females that I sell are 1.5 years to 2 years old after I have gotten to know them and ran a couple batches of their eggs in the 'bator and grown out a few of their kiddos. If after that time I do not like what they produce I will sell them as a layer.
Now.....notice I didn't even talk about what it would cost to raise a whole bunch of birds to adults just to sell them.......you just can't sell them for what it takes to feed and care for them until adulthood......this, IMHO, is why we see more chicks and or hatching eggs available on the Marans market vs. a mature bird.
Roosters are another story......
what kind of incubator did you get? Im looking and reading reviews before I buy one 
