The Chestnut-capped Piha reserve is a strange place. It is not high altitude or low altitude, but has species from both. I remember seeing a Great Thrush followed by a Red-throated Caracara. I think of the Orange-crowned Euphonia as a lowland species. I am not sure if it is possible to differentiate this from the Orange-bellied Euphonia from just this photo, so I have to trust the reserve checklist.
Africa (entire continent rather than south of Sahara)
AN
Antarctica
AO
Atlantic Ocean
AU
Australasia (Wallacea (Indonesian islands east of Wallace's line), New Guinea and its islands, Australia, New Zealand and its subantarctic islands, the Solomons, New Caledonia, and Vanuatu)
PAL
Eurasia (Europe, Asia from the Middle East through central Asia north of the Himalayas, Siberia and northern China to Japan)
IO
Indian Ocean
LA
Latin America (Middle and South America)
MA
Middle America (Mexico through Panama)
NA
North America (includes the Caribbean)
NO
Northern oceans
OR
Oriental Region (South Asia from Pakistan to Taiwan, plus Southeast Asia, the Philippines, and Greater Sundas)