## 3 Results and Discussion  
Table 1 shows the number of incubated, fertile, and hatched eggs, the fertility and hatchability of the incubated eggs, and the hatchability of the fertile eggs, according to the sibling contact regime during artificial incubation of red-legged partridge eggs. The mean fertility of the eggs found in this trial (89.8%) was higher than in previous reports on \(A\). _rufa_ under game farming conditions (50.2% to 85.6%) [9, 11, 12, 23, 24, 25]. Higher fertility found in this trial with respect to average values described in the literature might be explained by the eggs being gathered in the center of the breeding season in this trial, a period in which fertility of red-legged partridge peaks [1, 16, 26]. Good quality and fertility selection  
in the breeding flock could also have influenced the outcome [16]. No differences were found in fertility among the experimental batches (\(p>0.05\)), which evidences that eggs were randomly distributed among treatments. The mean hatchability of the incubated eggs (70.4%; Table 1) was within the range of values reported in the literature in red-legged-partridge under game farm conditions (31.0% to 84.1%) [7; 9; 11; 12; 24; 25; 27]. No differences (\(p>0.05\)) were found in the hatchability of all incubated eggs according to the sibling contact regime of the eggs during incubation (\(p>0.05\)). The mean hatchability of the fertile eggs (78.4%; Table 1) showed an intermediate value with respect to the interval reported for this species (57.6% to 91.6%) [7; 9; 11; 12; 23; 24]. This means that incubation conditions set in this trial were suitable for the specific requirements of this species. Moreover, no significant differences were observed in hatchability of fertile eggs in function of the sibling contact regime of the eggs (\(p>0.05\)). Previous scientific reports did not test the variation in hatchability of the red-legged partridge (\(A\). _rufa_) eggs submitted to different sibling contact regimes of the eggs during artificial incubation. Our results agree with those obtained by [PERSON] [28; 29] in chicken eggs, as well as those by [PERSON] et al. [30] in Bobwhite quail (_Colinus virginatus_) eggs, for which no effect on hatchability was observed when eggs were kept in contact in the hatching trays from days 18 and 21 of incubation, respectively. No difference was found among sibling eggs contact regimes during incubation for embryo development stages at embryonic mortality (Table 2). In general terms, development stages at which embryo mortality occurs coincided with the pattern and values reported for \(A\). _rufa_ by [PERSON] et al. [10] and were lower than mortalities reported at positive development, early embryonic, and late embryonic development when red-legged partridge eggs were submitted to pre-storage incubation [9]. In the present trial, however, eggs pipped but not out of shell were higher (6.3%, Table 2) than in the aforementioned studies (0.0% to 0.5%) [9; 10]. In our experiment, a lower incidence of fertile eggs not developed and positive development was observed than in a trial on \(A\). _rufa_ eggs submitted to different turning regimes during storage before incubation [12]. To our knowledge, there has been no study investigating embryonic mortality in relation to sibling contact regime in red-legged partridge eggs during artificial incubation. No differences were found among treatments in the initial weight of the fertile eggs before their incubation (19.2 g; \(p>0.05\)), in the egg weight after 20 days of incubation (17.3 g; \(p>0.05\)), and in the egg weight loss after 20 days of incubation (9.5 g; \(p>0.05\)) (Table 3). Recently laid egg weights fit those described for \(A\). _rufa_[3; 9; 10; 11; 25; 31] and other species of the _Alectoris_ genus [17; 32; 33]. The mean weight loss of the fertile eggs during the first 20 days of incubation was similar to the value found by [PERSON] [7] (9.2%) and slightly lower than the values reported by [PERSON] et al. [9; 10] (10.2% to 11.1%) for \(A\).