Nazca boobies are ground-nesting; usually nest on steep cliffs of high volcanic islands, and have a high density nesting with conspecifics in large colonies (Pitman and Jehl, 1998; Huyvaert and Anderson, 2004) . Birds lay one or two-egg clutches, never 3 (Anderson 1990; Clifford & Anderson 2001). It is fitter to have a two-egg clutch, but under threatening conditions it is more adaptive to save energy and hatch one egg (Drent & Daan 1980; Högstedt 1980). Incubation in these birds consists in transferring heat from the webs of their feet, which are more vascularized in females than males and in incubating than non-incubating individuals (Morgan et al 2003).
Nazca boobies are one of the most pelagic species of boobies during the breeding season, making foraging trips more tan 329 km away from the coast, the longest trip recorded for any booby species (Zalavaga et al., 2012). As mentioned before, the species has biparental care and usually both parents forage during the day leaving the nest unattended for long periods of time.
Nazca boobies have a potential lifespan of over 30 years and probably have post-reproductive lifespan (Anderson & Apanius 2003). Recent research has found support for the terminal investment hypothesis in these birds. Older birds performed a reduced proportion of v-shaped dives, indicating reduced foraging efficiency and senescence. Furthermore, these birds were shown to make a larger number of foraging dives per hour than younger birds, suggesting a larger investment in the reproductive effort at the end of their lifespan, in spite of their reduced reproductive success in comparison to younger birds (Estela & Anderson, 2013).