The North American grey wolf (Canis lupus ssp.) has recently been reclassified into 5 subspe cies (Nowak, 1995), down from 24 (Hall Sc Kelson, 1959). The new classification lists Ca nis lupus arctos, C.l. nubilus, C.l. occidentalis, C.l. lycaon, and C.L baileyi. Mitochondrial DNA studies (Coppinger Sc Schneider, 1995) show that wolves are indeed the ancestors of our domesticated dogs, which are now classified as Canis lupus familiaris and are considered one species. The variability in size by weight in adult wolves ranges from 30 kg to 75 kg on the aver age, with some northern wolves weighing as much as 80 kg and the Arabian wolf weighing around 20 kg. The weight of dogs ranges from approximately 1.5 kg for a chihuahua to 130 kg for an Old English mastiff. Yet, behaviorally the similarities between wolves and dogs are im pressive. The ethogram of the wolf (Goodmann Sc Klinghammer, 1994) contains more than 190 distinct behavior patterns shared by dogs. Variations in behavioral characteristics between wolves and dogs are due to selection during do mestication, but the differences are more quan titative than qualitative. However, some quali tative differences in behavior patterns exist as well. For example, many breeds, or even indi vidual dogs, have lost the ability to howl; and most livestock-guarding dogs lack certain predatory behaviors that are still found in herd ing dogs in a somewhat modified form.