Cuculus optatus
Silhouette: Nicolas Huet le Jeune and Jean-Gabriel Prêtre (vectorized by T. Michael Keesey) · PhyloPic
In 3 days ~30% in a week ~50%
The Oriental cuckoo or Horsfield's cuckoo (Cuculus optatus) is a bird belonging to the genus Cuculus in the cuckoo family Cuculidae. It was formerly classified as a subspecies of the Himalayan cuckoo (C. saturatus), with the name 'Oriental cuckoo' used for the combined species. Differences in voice and size suggest that it should be treated as a separate species. The binomial name Cuculus horsfieldi has often been used instead of Cuculus optatus, but is now usually considered to be a junior synonym.
It is 30–32 centimetres long with a wingspan of 51–57 centimetres and a weight of 73–156 grams. The adult male has a grey head, breast and upperparts. The belly is creamy-white with dark bars. The vent is frequently buff with few markings. The legs and feet are orange-yellow and there is a bare yellow ring around the eye. Adult females and juveniles occur in two morphs. The grey morph is similar to the male but has a brownish wash on the breast. The rufous morph is reddish-brown above, paler on the underparts and with strong dark bands all over including the rump.
The common cuckoo (C. canorus) is very similar in appearance but is slightly bulkier with longer wings and... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Taroko National Park | 🇹🇼 Taiwan | |
| 2 | Nikko National Park | 🇯🇵 Japan | |
| 3 | Raja Ampat | 🇮🇩 Indonesia | |
| 4 | Daintree National Park | 🇦🇺 Australia |
With luck
About 10% of wildlife watchers report an Oriental Cuckoo sighting in Nikko National Park on a given day, based on 42 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 58th most-seen of the 102 birds we can rate there. Over three days the chance rises to about 30%, and over a week to about 50%, if each day is a fresh chance.
May
In that month about 30% of wildlife watchers report an Oriental Cuckoo in Nikko National Park on a given day, against under 5% in March–April and July–December, the lowest months.
Between 7 and 10 am
Across all the parks we cover, that three-hour window holds the most Oriental Cuckoo sightings with a recorded time, and about 7 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Among the best
Of the 4 parks where we can rate Oriental Cuckoo sightings, Nikko National Park ranks 2nd at about 10%, level with the leaders once rounded. The best odds are in Taroko National Park (Taiwan, about 10%).
Same genus: Cuculus
The closest relatives of the Oriental Cuckoo that you can see in Nikko National Park (genus Cuculus, Typical Old World Cuckoos) are Common Cuckoo (about 30%) and Lesser Cuckoo (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Oriental Cuckoo is recorded against all the birds logged in Nikko National Park (42 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
