<P> The killdeer has a clutch of four to six eggs, buff to beige in colour, with brown markings and black speckles . It is about 38 by 27 millimetres (1.5 by 1.1 in) in size . These eggs are laid at intervals of 24 to 48 hours . When these eggs are being laid, the energy expenditure of both sexes is at its highest; the female needs to produce eggs, whereas the male needs to defend its territory . Both the female and male are closer to the nest site during egg laying and incubation, with the male generally being closer to the nest during all stages of breeding . This latter fact is likely due to the male's increased investment in nest - site defense . Up to five replacement clutches can be laid, and there are occasionally two broods . The eggs are incubated for 22 to 28 days by both the male and the female, with the former typically incubating during the night . The time dedicated to incubation is related to temperature, with one study recording that killdeer incubated eggs 99% of the time when the temperature was about 13 ° C (55 ° F), 76% of the time when it was around 26 ° C (79 ° F), and 87% of the time during temperatures of about 35 ° C (95 ° F). When it is hot (above at least 25 ° C (77 ° F)), incubation does not take the form of warming the eggs, but instead occurs through the cooling of eggs, generally through shading . </P> <P> The day after the young hatch, they are led by both parents out of the nest . The family then generally moves to a feeding territory with dense vegetation which the chicks are able to hide under when a predator is near . The chicks are raised, at least in single - brood pairs, by both parents, likely because of the high failure rate of nests and the need for both parents to be present to successfully raise the young . In two parents broods, the young are usually attended by only one parent, generally the female, until about two weeks of age, after which the non-attentive parent occasionally tends the young . Otherwise, the non-attentive parent is generally at least 23 metres (75 ft) away from the chicks . Periods of attentiveness for each parent generally last about one to one hour thirty minutes . This time is mainly spent standing when the chicks are young, with the time dedicated to this decreasing as the chicks get older . When the young are below two weeks of age, the attending adult dedicates little time to foraging . The non-attentive adult defends the young most of the time when they chicks are less than a week old, but this task steadily shifts onto the attentive adult, until about three weeks of age, when the attending parent does almost all of the defense . One parent at a time generally broods the chicks, and does so frequently until they are two days old . They are also brooded, until about 15 days after hatching, during rain, and, until about 18 days after hatching, at night . The only time when the young are not in the presence of a parent is when the parents are responding to a predator or an aggressive conspecific, or when mating . </P> <P> There are sometimes one parent broods when a pair has two broods . This brood is watched over by the male, who is able to hatch the chicks on its own, unlike the female . In this case, the adult does not spend most of the time standing, and the time it did spend did not decrease as a function of age . Like attentive adults in two parent broods, the sole parent of a brood increases the time spent foraging as the chicks get older . </P> <P> The young fledge about 31 days after they hatch, and generally move to moister areas in valleys and on the banks of rivers . They may be cared for by their parents for up to 10 days after they fledge, and exceptionally 81 days after hatching . </P>

What bird builds its nest on the ground