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This study examined the potential of animals as vectors for mesquite seedling establishment via fecal deposition. Cattle, deer, and coyote fecal material containing emerging mesquite was located in May 1994 on a clay loam site in north Texas and assigned to two grass competition treatments (clipped to 3-cm height, or unclipped) and three moisture treatments (rainfall, rainfall + four 1.25-cm irrigations, or rainfall + one 10-cm irrigation). Except for a 2-week period in August 1993 when feces were deposited, cattle grazing was excluded from the site during the study and for several years prior to study initiation. Seedling emergence and survival were quantified throughout 1994, a dry year, and 1995, which had precipitation well above normal. By spring 1995, survival of 1994 seedlings (all treatments pooled) was 16.6, 9.3, and 1.3% at deer, cattle, and coyote fecal sites, respectively. Survival of 1994 seedlings was not affected by moisture or clipping treatments. New cohorts of emerging seedlings occurred from the same fecal sites during 1995. High rainfall during summer 1995 increased percent survival of 1995 seedlings when compared to survival of 1994 seedlings, even though grass growth was much greater in 1995 than in 1994. A strong trend emerged in which survival of 1995 seedlings appeared to be greater when surrounding perennial grasses were clipped (37.0% in clipped plots vs. 9.4% in unclipped plots), but this was not statistically significant (P less than or equal to 0.14). By spring 1996, average number of seedlings emerged per site (1994 and 1995 cohorts combined) was 7.8, 5.2, and 4.5; number of established seedlings per site was 0.8, 0.6, and 0.3; and percent survival was 12.1, 13.5, and 6.5% at cattle, deer, and coyote sites, respectively. Mesquite seedlings were capable of establishing from feces of all three animal vectors within dense, ungrazed stands of perennial grass.