Serin (Serinus serinus) Science Article 2
Given that in many bird species females are subordinate to males and that, in general, subordinate individuals are more vigilant than dominants ones, we should predict foraging females to be more vigilant than males. This prediction is tested here in flocks of Serins Serinus serinus, where several males may forage together. We compared 41 winter foraging pairs (male versus female). Results showed that male Serins were dominant over females. Proportion of males around the focal pair had a significant effect on vigilance frequency and time spent vigilant and foraging in males, but not in females. When the percentage of males around the focal pair was lower than 50%, females displayed higher vigilance and less foraging time than males; when the percentage of males increased, males and females displayed a similar vigilance pattern. We suggest therefore that in flocks with several males (i.e. high ranking individuals) foraging together, males as well as females should keep the other flock companions as well as predators under surveillance, so that in the end the difference in vigilance rate of males and females would be diluted
Domenech J. & Senar J.C., ARDEA 87 (2): 277-284.