Why does perrault say that buck is one in ten thousand?

In Jack London's "The Call of the Wild," Perrault describes Buck as "one in ten thousand" because of Buck's exceptional qualities that set him apart from other dogs. Buck possesses remarkable strength, intelligence, and adaptability, making him ideally suited for the harsh conditions of the Yukon wilderness. His unique combination of instincts and skills enables him to thrive in a challenging environment, highlighting his extraordinary nature compared to the average sled dog. This distinction emphasizes Buck’s potential as a leader and Survivor in a brutal, primal world.