A marked retrieve is a retrieve of a bird which the dog has seen fall. A blind or unseen retrieve is a retrieve of a bird which the dog has not seen fall. There are a few pertinent facts about marked and blind retrieves which bear looking at. The major issue being that the sequence in which you develop the two behaviors in a young dog has a major impact upon how easy the training job will be for both the dog and the trainer. I have a few opinions on marked retrieves which I would like to share.
A dog does not need much training on marked retrieves. He is born with the behaviors to accomplish a marked retrieve. An 8-week-old puppy will go fetch a thrown object and deliver it to hand with no training. If you look at it from an evolutionary standpoint, the dog's ancestor must have had the ability when he saw a bird land on the ground in the distance to go to it, catch it, and eat it, without the benefit of any training from man. If he couldn't do that he probably did not live very long. Thus I look at a dog as having an innate ability to "mark".
What the dog needs training on is obedience, steadiness in the face of high distraction, and stopping on the whistle to take a hand signal. These behaviors are not innate and must be trained.
Giving the dog a lot of marked retrieves early in his training program makes it harder for him to develop steadiness and harder for him to develop proficiency at whistle stopping, taking casts and blind retrieves. Here are three traditional practices that interfere with getting to the end goal of a well trained gundog:
(1) Give young puppies lots of uncontrolled retrieves to develop drive.
Drive is determined by the genes the puppy inherited from his parents. No amount of training is going to increase that inheritance. However, if you build a lot of out-of-control behaviors and then use force to get the control back, you quite likely will inhibit with the punishment the amount of drive that was inherited.
(2) Give puppies a lot of birds early in life in an attempt to build drive.
Birds bring out the wildness in a puppy and make it more difficult for him to become proficient in control behaviors such as steadiness, whistle stopping and blind retrieves. Birds are simply an accelerated distraction level. The puppie's fundamental gundog behaviors should be developed and made proficient with dummies first. Then the puppy graduates to using the occasional bird.
(3) Give puppies lots of marks before starting blinds and/or before steadying. If you break it down to a behavior chain, marks and sight blinds and memory blinds, and lining drills are all training exercises that train a dog NOT to stop and look for a cast.
The behavior chain goes like this:
Go out ---------------------------------------------------------- Reward (get the dummy or bird)
The behavior chain for a blind retrieve goes like this:
Go out ------------------Stop/look-cast--------------------Reward (get the dummy or bird)
If you look at it in terms of operant conditioning, every mark and every lining exercise "programs"(trains) the dog to go on without stopping (to Not-Stop).
Every marked retrieve and every lining drill you do makes it more difficult for the dog to learn to stop/look for a hand signal. That stop/look is the most important piece of a blind retrieve. It should be trained early, and kept in balance with the marked retrieves and lining drills
The crux of the easy training route to an excellent gundog lies training the behaviors that need training, and training them in the correct sequence. Marked retrieves don't need much training. They are natural to a dog. For young dogs, The primary use of marked retrieves should be as rewards for sitting quietly. Here is the way to start that process:
Lizzie gets steadiness lesson with clicker - bridging from food reward to retrieve reward
Blind retrieves are not natural to a dog, therefore they are more in need of training. The earlier the better.
The essence of the message is to get the sequence right when you train your retriever puppy:
(1) Train obedience and steadiness first. Marked retrieves should only be given occasionally as a reward for sitting quietly.
(2) Train whistle stops and casts
(3) Train blind retrieves
(4) Train to leave the close marked falls and go for the long unseen cripple.
(5) After the dog is proficient in the above, then he can have a few marked retrieves.
Training the essential gundog behaviors in the correct sequence will make the job much easier for the dog and much more fun for the trainer.