On the Alps, Alpine ibex lives in sympatry mainly with chamois Rupicapra r. rupicapra, less frequently with mouflon Ovis ammon mousimon and with domestic ruminants (sheep, goats, cattle) (Gauthier et al., 1991).

8.1. Interactions with wild ungulates
Contradicting what has often been hypothesised, there is no evidence of competitive interaction between Alpine ibex and chamois, as suggested from studies on behaviour (Pfeffer & Settimo, 1973), space use (Resche-Rigon, 1982), and demography (Durio et al., 1988).
With the exception of some cases of hierarchy in the use of salt licks, the two species often can be found in near contact to each other (Gauthier et al., 1991). Only in atypical and sub-optimal conditions for Alpine ibex, cases of competition with chamois have been described. This is what happened, for example, in Austria after the introduction of alpine ibex in environments virtually without any rock cliff and with a high density of chamois (Schröeder, 1983). It has also been hypothesised that the decline of chamois may be caused by a possible parasite interaction between the two species (Schröeder & Kofler, 1985).

8.2. Interactions with domestic ungulates
Between domestic and wild ungulates, on the alpine meadows, four kind of interactions are possible: space-time interaction, trophic interaction, sanitary interaction and genetic interaction (Bassano, 1994).

8.2.1. Space-time interaction
In this kind of interaction, the use of a same resource is avoided, or happens in different times. The presence of domestic ungulates, grazing on open meadows, causes important modifications for habitat selection, social aggregation and the activity budgets of Alpine ibex. In the presence of cattle, Alpine ibex: i. reduce the use of plane meadows in favour of areas at a higher altitude and with more rocks; ii. dedicates less time to feeding during daytime (Bassano et al., 1997b); iii. aggregates in smaller groups (Bassano et al., 1997a).

8.2.2. Trophic interaction
While for the Pyrenean ibex the diet niche overlap with domestic ungulates appears to be low (Garcia-Gonzales & Cuartas, 1989), in Alpine ibex the probability of a trophic interaction with sheep and cattle is much higher: on Alpine meadows the diet overlap indexes among these species reach the highest values described in the literature (Bassano, 1994). If the resource should be limited, the possibility of a competition among these species, in conditions of sympatry, might be high.

8.2.3. Sanitary interaction
A possible exchange among domestic and wild ungulates on alpine meadows has been shown in many studies (Balbo et al., 1978; Artois et al. 1992; Lanfranchi, 1982 e 1993; Rossi et al., 1988; Peracino & Bassano, 1991). Alpine ibex can be involved in such events regarding parasitic, bacteric and viral diseases (De Meneghi et al., 1996).
Sheep and goats are responsible for the contamination of meadows occupied by Alpine ibex and chamois (Rossi, 1990) and, on the other hand, can be infected with the gastro-intestinal nematodes of the wild ungulates (Rossi et al., 1985).
The highest prevalence of transmittable diseases among domestic and wild ungulates are found in situations of high pasture pressure (Bourgogne, 1990). The main diseases found in sympatric situations between domestic species and ibex are paratuberculosis, Q fever and salmonella (Gauthier et al., 1991). The recent discovery of some cases of brucellosis in Alpine ibex (Peracino et al., 1996; Ferroglio et al., 1998), inside the Gran Paradiso population, following a case of infection inside a pastured sheep herd, shows that this disease could potentially become a serious epidemiological and sanitary management problem.

8.2.4. Genetic interaction
The possibility of a hybridisation between ibex and domestic goat is well documented (Couturier, 1962). As a matter of fact, domestic goat has played an important role in the history of reintroduction of Alpine ibex (Gauthier et al., 1991b), and the first attempts have been done also releasing hybrids bred in zoos and often in the presence of domestic goats (Desax, 1978; Varicak, 1978; Peracino e Bassano, 1986; Giacometti, 1988; Buchli & Abderhalden, 1998a; Passerin d'Entreves, 2000).

Even if hybrids in nature usually are unable to transmit their genes to the following generations, it has been shown that goats abandoned in the wild often attract subadult Alpine ibex males and that from these encounters fecund hybrids can be born (as an example: 7 hybrids born in Haute Savoie in 1985, Gauthier et al., 1991).