Group size influences individual vigilance in different bird species. Most studies have shown that animals spend more time for feeding and less time on vigilance when in groups. Apart from group size, additional factors, such as group density, age, sex, and season, are considered to influence vigilance behaviors. The aim of the present study was to investigate the effects of flock size and human presence on vigilance and feeding in the Eurasian Coot (Fulica atra) during the breeding season. This work was performed in Yorukkirka Lake (Eskisehir, Turkey) from March to August 2005. No correlation was found between flock size and vigilance rates during either human absence or presence. On the other hand, when comparing behavioral differences between human presence and absence, humans appeared to have an important negative effect on vigilance rates, vigilance duration, and feeding behavior, regardless of flock size.