Greater flamingos Phoenicopterus roseus are partial capital breeders

Capital breeding refers to a strategy in which birds use body stores for egg formation, whereas income breeders obtain all resources for egg formation at breeding sites. Capital breeding should occur more in large‐bodied species because the relative cost of carrying stores for egg formation becomes smaller with increasing body size. Based on a comparison between stable isotopes of carbon and nitrogen in potential prey at wintering sites and eggs, we examined whether greater flamingos use nutrients stored earlier in the year for egg production. Our results suggest that the greater flamingo is a partial income breeder, since prey for egg formation were obtained both in overwintering sites and at the breeding site. This may be because there are selective pressures for nesting females to lay soon after arriving at the breeding site, which may be facilitated by arriving at the breeding site with developed ovarian follicles.