The aim of this study was to compare two different types of feeding enrichment (vegetarian vs. carnivore) through the daily activity, space use and inter-individual distances in a captive Iberian wolf ( Canis lupus signatus ) pack housed at the Barcelona Zoo. Multifocal sampling methods were used for data collection and instantaneous scans were made at 15-min intervals during sessions of varying duration. The enrichment sessions were carried out once a day, three days per week –Monday, Wednesday, and Friday- repeating the delivered schedule of items every two weeks. Thus, both feeding phases included six different enrichment sessions; the vegetarian phase included chopped fruit – apples inside a burlap sack, scattered bananas, peaches, frozen pears, and oranges, and kiwis inside a frozen water block; the carnivore phase included animal products -beef raw lean meat inside a burlap sack or inside a frozen water block, horse leg, live carp, frozen rabbit skin and live grasshoppers-. There were individual differences in the response to both feeding enrichments. Only the carnivore enrichment provoked statistically significant differences in exploration, locomotion, inactivity and not visible. Only the indeterminate zone showed changes during both enrichment phases. The inter-individual distance between Iberian wolves was statistically significantly lower during both feeding enrichment phases –especially during the carnivore as compared to the vegetarian phase- than during the baseline phase. Enrichment items designed more according to the natural history of these animals seem to have a greater capacity to improve the wolf welfare. Future studies on this species are necessary to improve husbandry techniques, welfare, and conservation programs.

Maintaining biologically functional and compatible social groups is a primary welfare concern for captive animals. The aim of this study was to determine the effect of a pack size change -due to a new yearling- on the daily activity, use of space and inter-individual distance in a mated pair of Iberian wolves ( Canis lupus signatus ) housed at the Barcelona Zoo. Multifocal sampling methods were used for data collection, and instantaneous scans were made at 15-min intervals during 10-h sessions. 432 sampling points were balanced for the daily periods – morning, midday, and afternoon - for two different phases: dyad and triad phase. The subjects studied during the dyad phase - from April to May 1999 - were the mated pair. For the triad phase - from April to May 2000 – we studied the mated pair and the new yearling. When comparing these two study phases, there were statistically significant differences for the daily activity and the use of space. The mated pair used the space more homogenously during the triad phase. In the same phase, the inter-individual distance between the mated pair was statistically significantly closer in the morning and in the midday. The mated pair also showed individualized results for their daily activity, use of space and inter-individual proximity during the triad phase. Increasing understanding about the pack size enables the improvement of management to provide wolf packs with the most appropriate social environments.