This study investigated behavioral responses towards novel objects by equids. Goals were to (1) compare responses of feral horses and donkeys towards novel stimuli and (2) identify variables such as age, species, colour, or facial whorl position that may predict investigative behaviour. Measuring investigative behaviour using novel objects may benefit wildlife conservationists, because it has predicted dispersal and survival in reintroductions. It could also improve management strategies for feral and invasive species. It was hypothesized that a higher proportion of juveniles (here defined as = 2 y) would investigate novel stimuli. Three novel objects (Ball, Cube, and Saucer) were positioned on feeding grounds and videotaped in 60 minute trials at least 1 week apart. Responses were recorded only from those equids likely to have perceived the object (criterion: within 25 m of object and head oriented towards it). Responses were classified as Investigation (criterion: approach within .5 m and orient) or No Investigation. While the total percentage of feral equids investigating the object varied across trials (Saucer = 17.3%, Ball= 18.5%, Cube= 32.2%), the proportions of juveniles and adults that investigated were not significantly different from each other in any trial. In the Ball trial (N = 65), 17.2% of juveniles and 28.6% of adults investigated (Fisher's Exact Test (FET), p=.604). In the Cube trial (N=87), 34.3% of adults and 23.5% of juveniles investigated (p=.564, FET). In the Saucer trial (N=81), 18.8% of adults and 11.8% of juveniles investigated (p=.723, FET). Proportion of individuals investigating did not differ significantly between species (horses vs. donkeys), in the 2 trials where donkeys appeared: Ball, p=1.0 (FET) and Cube, p=.491 (FET). These findings suggest that the level of investigative behaviour does not decrease with maturation from juvenile to adult in the typical pattern of behavioural development of feral horses.