Great Cuckoo-dove

Appearance

The great cuckoo-dove is a large and long-tailed pigeon, with a length of 47.5–52.5 cm and a weight of 208–305 g. A slight crest on the back of the head gives it a "big-headed" appearance. Birds of the nominate subspecies have the head, neck, and breast blue-grey or cream-white with a pale bluish-grey tinge, turning purplish grey on the back of the neck and upper back. The throat and belly are white, with the latter frequently having a pinkish tinge. The upper back, back, rump, and uppertail-coverts are chestnut-brown. The wings are darker chestnut-maroon, becoming blackish further from the body, and are black below. The underparts are pale bluish-grey.

The outermost rectrices are greyish-white with black bases and black stripes near the end, while the second-outermost are coloured similarly with black-and-chestnut stripes. The amount of chestnut increases moving inwards, with the central rectrices being almost entirely chestnut with only a small amount of black and grey near the base. Individuals of the nominate subspecies vary clinally in appearance, being darkest in the north and palest in the southwest of their range. In males, the iris is yellowish-white with a red outer ring and the orbital skin is reddish. Females have a more yellowish iris and duller orbital skin. The feet are pink to purplish-red in adults.

Newly hatched nestlings are pinkish-white. Older nestlings have black bills and feet. Juveniles are dull grey-brown, with dirty-white throats and bellies. The wings are darker than the rest of the body and the wing-coverts, rump and uppertail-coverts are reddish-brown with dark edges. The central rectrices are sooty-brown with a rufous tinge. The cere and base of the bill are red to purplish pink and the rest of the bill is yellowish-brown, sometimes with a white tip.

The great cuckoo-dove is easily recognised by its large size and distinctive appearance, with the pale underparts contrasting strongly with the richly-coloured upperparts. However, it may still be confused with the "slender-billed cuckoo dove", a species complex that includes the Amboyna and Sultan's cuckoo-doves. These cuckoo-doves can be distinguished from the great cuckoo-dove by their smaller size and vinous-tinged, more strongly barred underparts, which contrast less with the upper body.

Distribution

The great cuckoo-dove is native to Papuasia and Wallacea. In the Maluku Islands, it is found on Buru, Ambon, Seram, Obi, Bacan, Kasiruta, Kayoa, Halmahera, and Morotai. On New Guinea, it occurs on most of the mainland, excluding the Trans-Fly lowlands, as well as the satellite islands of Waigeo, Salawati, Misool, Yapen, Biak, Kumamba, Kairiru, Manam, Karkar, Goodenough, and Fergusson.

Status

The great cuckoo-dove is classified as being of least concern by the International Union for Conservation of Nature due to its sufficiently large range and stable population. Its population has not been estimated, but it is thought to be generally uncommon throughout its range, although it can be locally common in hills and mountains. It is fairly common in Papua New Guinea and has a density of 4–6 birds per square kilometre in the Crater Mountain Wildlife Management Area, although it can be uncommon in the northeast of the country. On Seram, it is rare in the lowlands, but rather common at higher elevations.

Behavior

The great cuckoo-dove is usually seen either alone or in pairs in the midstorey or canopy of the forest, although it will form groups of up to ten birds at fruit trees, sometimes joining flocks of other frugivores. It flies under the canopy and is rather fast, with slow, powerful, and graceful wingbeats.

Habitat

The species mainly inhabits primary forest and forest edge, but is also found in logged forest, secondary growth, and gallery forests on Biak. It is found at elevations of up to 3,380 m on mainland New Guinea and up to 1,190 m on Karkar Island. On the Maluku Islands, it is found from 115–1,400 m, but is most common above 800 m.

Reproduction

Its typical courtship display consists of a deeply undulating flight, with the bird flying sharply upwards, spreading its wings and tail or clapping its wings together at the top of the flight, and descending sharply. Another reported display involves the bird flying up obliquely from a perch and then returning after flying in a wide circle, similar to the displays performed by "Macropygia" cuckoo-doves. Breeding occurs throughout the year and varies in different parts of its range. On Buru, nestlings have been observed in February. On New Guinea, breeding seems to occur throughout the year, with nests or young having been observed from March to August and from October to December, and is thought to peak in the latter period. Nests are flat or slightly concave platforms made of sticks, moss, roots, and ferns, lined with fine plant material. They are usually located in a tree or bush at a height of 1.2–5 m, although some have been observed as high up as 12 m in "Pandanus" palms. Nests may sometimes be made on rocky ledges in caves or river canyons at heights of 2.4–12 m.

Great cuckoo-doves lay a single white egg, measuring 37.1 mm–40.0 mm × 25.0 mm–26.8 mm. Captive birds are known to lay multiple clutches if their first clutch fails. Both parents may incubate the egg, which has been observed to hatch after 16 days in captivity and after 22 days in a wild nest. Young are brooded until 13 days after hatching and leave the nest 25 days after hatching. Fledglings begin picking food by themselves 35 days after hatching.

Food

The great cuckoo-dove feeds on fruits and small seeds, preferring plants in the Araliaceae and especially those in the genus "Heptapleurum", such as "Heptapleurum chaetorrhachis". Feeding usually takes place in the canopy, but occasionally occurs on the ground. It has been observed defending fruiting shrubs that it is feeding on by scaring off other birds that attempt to feed on the shrub, including birds-of-paradise, "Ailuroedus" catbirds, honeyeaters, and berrypeckers. The dove attacks other birds by "clapping" its wings together loudly, while trying to land on the intruding bird. Defending fruit sources is an uncommon foraging behaviour as it occurs only in certain conditions, requiring intermediate crop sizes and moderate rates of visitation by other birds. The species has also been observed eating soil, and several individuals have been found to have stones in their stomachs.

Predators

Known parasites of the species include the feather louse "Columbicola taschenbergi" and "Coloceras museihalense". The pygmy eagle is a possible predator.