The social and maintenance behaviors of two pairs of Mexican gray wolf in captivity were studied. Wolves belonged to Zacango (ZZ) and Leon Zoo (LZ). For the ZZ pair significant differences were observed (p<0.01) for the social behaviors, whereas no differences were found for neutral or affiliative behaviors. The LZ pair showed no differences in social behavior before the breeding season, but after this significant differences were observed for playing and sexual activity (p<0.001). Wolves showed a preference (p<0.0001) to perform their activities on a reduced place far away from the human transit, especially those related with the courtship behavior. For the ZZ pair a total number of 389 mounting observations were registered during 11 consecutive days, most of them with pelvic movements but only two culminating with copulation (0.6%). The LZ pair showed a reproductive activity of 180 mountings, three of them culminating with copula (1.6%); none of the pairs showed reproductive success. Reproductive success depends on both physiological and behavioral compatibility, but some other causes may be involved in the reproductive failure of the ZZ pair, among them the stress of restraining for the cytology studies and the housing conditions like the presence of large predators as closer neighbors to the wolves.