The Grey Partridge - Perdix perdix - also known as the Hungarian Partridge, was successfully introduced to many parts of the world for shooting, including vast areas of North America, where it is most commonly known as Hungarian partridge, or just "Hun". Widespread and common throughout its large range, the Grey Partridge is evaluated as Least Concern on the IUCN Red List. 

However, research in European countries between 1980 and 2009 shows an alarming decline in numbers of 82%.

 The Grey Partridge is a medium-sized, plump brown-backed bird, with pale brick-red head, grey flanks and chest. The belly is white, usually with a large chestnut-brown patch. Young are mostly yellow-brown and lack the distinctive face and underpart markings.
The song is an explosive, metallic, creaking throaty kieerr-ik, kieerr-ik, given at all times, especially at night. When surprised, they take to the wing with loud wing noise and an excited "pitter pattering" call.

They are mainly seed-eaters, but will add insects and greens in winter and spring. The young in particular eat insects. During the first 10 days of life, the young can only digest insects. The parents lead their chicks to the edges of fields, where they can forage for insects. 

This bird breeds on farmland across most of Europe into western Asia. Breeding starts in April with one clutch per season. The nest is usually on the ground under the cover of a hedge or other tall plants. The eggs are smooth, glossy, and uniform olive-brown. Hens lay between 9 and 20 eggs, which she incubates for 23 to 25 days. The chicks are able to feed themselves, but both parents care for them. The chicks wing feathers appear after about 5 days and they can flutter at 10 days, but they are not fully fledged until 28 days.

They form coveys which keep close together outside the breeding season. Grey Partridge are sedentary and even the young rarely move far from their natal grounds.

Changes in farming practices, such as autumn sowing, hedgerow destruction and use of insecticides and herbicides have all contributed to the decline.