The Slovenian karst region and similar types of land are difficult to cultivate and often exposed to the process of being abandoned and overgrown with shrubs, trees, and brushwood. Co-grazing in a mixed group may be a way to optimize the management of sheep and goat flocks in such areas. To obtain more knowledge of the natural behavior of small ruminants, the experiment was designed on pasture in the mountain karst region. The experimental area was divided in 6 paddocks, of which 3 paddocks were covered with grass, herbs, and legumes (i.e., grassy paddock [GP]). In the other 3 paddocks the area was additionally overgrown with hazel, beech trees, and bushes (i.e., woody paddock [WP]). In a mixed flock of 40 Slovenian local sheep breed (Istrian Pramenka) and 10 crossbreed goats (Saanen x Alpine goat), 10 animals per species were focally observed during daylight (0500-2100 h). The natural behavior was scored on 12 d, 2 consecutive days in each of the paddocks. Animals were rotated between 6 paddocks according to the balanced schedule. They stayed at each paddock for 5 or 6 d. Observations started on the third day after moving the animals into a specific paddock, following 2 d of adaptation. The results indicated that botanically diverse paddock together with climate conditions affected the behavior. Goats were grazing more (P < 0.001) whereas sheep less in the WP (P = 0.05). In sheep, drinking and salt consumption were higher (both P < 0.001) in the WP, suggesting that salt triggered additional water consumption. The WP enabled conditions where more comfort behavior, that is, autogrooming (both species P < 0.001) and object grooming (both species P < 0.001), was performed. On the second day of observation, animals grazed more compared to the first day (both species P < 0.001), most likely due to lower forage availability. Goats drank (P < 0.001) and consumed more salt on the second day (P < 0.001). With higher temperature sheep and goats grazed less (P < 0.05 and P < 0.001, respectively) and goats drank more (P < 0.05). Sheep showed more while goats less autogrooming when temperature was lower (both P < 0.001). More autogrooming was shown on the second day of observation but only in goats (P < 0.001). The performed behavior of co-grazing sheep and goats suggests different foraging strategies and adaptation between the species, which may be taken into account for management decisions under specific environmental conditions in the mountain karst region.