Border collies are working dogs. They have a reputation for smartness, and they are highly motivated. They are bred to herd sheep indefatigably all day long. Absent that task, they must be given something else to do or they go stir crazy.
Chaser proved to be a diligent student. Unlike human children, she seems to love her drills and tests and is always asking for more. “She still demands four to five hours a day,” Dr. Pilley said. “I’m 82, and I have to go to bed to get away from her.” ...
As with other animals for which prodigious feats of cognition have been reported, like Alex the gray parrot or Kanzi the bonobo, it is hard to place Chaser’s and Rico’s abilities in context. If their achievements are within the general capacity of their species, why have many other instances not been reported? If, on the other hand, their achievements are unique, then either the researchers have lucked out in finding an Einstein of the species, or there could be something wrong with the experiments like a Clever Hans effect.
Dr. Pilley said that most border collies, with special training, “could be pretty close to where Chaser is.” When he told Chaser’s dog breeder of the experiment, “he wasn’t surprised about the dog’s ability, just that I had had the patience to teach her,” Dr. Pilley said.
Dr. Horowitz agreed: “It is not necessarily Chaser or Rico who is exceptional; it is the attention that is lavished on them,” she said.
Border collies are a handful if you don't own a flock of sheep to keep them busy.