The suppression of immobilizing and killing behavior in border collies would NOT be considered an adaptation. Adaptations typically refer to traits or characteristics that have evolved in a species over time to enhance their survival and reproduction in a specific environment.
In the case of border collies, their behavior is more related to training and domestication by humans rather than a genetic adaptation that has evolved over generations. It's a learned behavior rather than an inherited trait that enhances their survival in the wild. The other examples you provided, such as resistance to fungal blight in American chestnut trees, dense fur in Arctic mammals, and small wind-dispersed seeds in cottonwood trees, are all examples of adaptations that have evolved to increase the organism's fitness in their respective environments