Yellow-billed cuckoos are probably monogamous, though their breeding system has not been well studied. Breeding pairs form in May or June, and pairs may visit prospective nest sites together before choosing a location. Males may attempt to procure or keep a mate by offering sticks and other nest materials to their mate as well as feeding them (Eaton, Erlich et al).
Mating System: monogamous
Yellow-billed cuckoos begin breeding in mid- to late-May. Most populations breed once per year, though some eastern populations may raise two broods in one breeding season. The male and female build the nest, which is made of twigs, lined with roots and dried leaves, and rimmed with pine needles. The female may begin laying eggs before nest construction is complete. She lays 1 to 5 (usually 2 or 3) light blue eggs, and begins incubating after the first egg is laid. Incubation is done by both parents, and lasts 9 to 11 days.
Yellow-billed cuckoo chicks are altricial at hatching, and are brooded often by the parents for the first week or so. Both parents feed the chicks, which begin to leave the nest 7 to 9 days after hatching. They begin to fly about 21 days after hatching. Soon thereafter they leave the nest for good. The male will usually take care of the first fledgling, and the female will care for the rest (Ehrlich et al.). There is little information available on when yellow-billed cuckoo chicks become independent from their parents. Most yellow-billed cuckoos begin breeding at age 1.
Some yellow-billed cuckoos may parasitize other birds by laying eggs in the nest of other parents. They may lay eggs in the nest of other yellow-billed cuckoos, or in the nests of other bird species, including black-billed cuckoos, American robins, gray catbirds and wood thrushes.
Breeding interval: Most populations breed once per year, though some eastern populations may lay two broods in one breeding season.
Breeding season: Yellow-billed cuckoos begin breeding in mid- to late-May
Range eggs per season: 1 to 5.
Average eggs per season: 2 to 3.
Range time to hatching: 9 to 11 days.
Range fledging age: 7 to 9 days.
Average age at sexual or reproductive maturity (female): 1 minutes.
Average age at sexual or reproductive maturity (male): 1 minutes.
Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate)
Average eggs per season: 3.
Male and female yellow-billed cuckoos incubate eggs, brood and feed chicks and protect the nest from predators. They also keep the nest clean by removing the fecal sacs of the chicks. After chicks have left the nest, the parents continue to feed them until they are able to care for themselves. The length of this period is unknown.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female); pre-independence (Provisioning: Male, Female, Protecting: Male, Female)