Fauna
The creation of vast reservoirs has without doubt considerably reinforced the ornithological interest of this part of the Champagne wetlands, already a favoured migratory stop by water birds because of the presence of many ponds and vast zones of humid natural meadow.
Over 250 species of birds have been observed so far on the lakes and their forest boundaries, among which some prestigious feathered hosts, for whom the Champagne wetlands brings the only French site for regular wintering: the white tailed eagle, Bewick and Whooper swans ...
Place of refuge also for the thousands of Cranes who stopover, a few score of Bean and Greylag geese... , falcons and other osprey... The deep forests also shelter some remarkable birds (goshawks, woodpeckers...) but it is especially the big fauna (deer, roebuck and boar) that makes it important.... The Fauna in the Orient is rich, no doubt about it : hairs, feathers and scales..., claws, beaks and teeth.
In the corner of a path, you may be lucky and get to observe Sir Fox, his accomplice the Badger or Lady Marten...
Amphibians and reptiles
In May, a low plaintive note rises up into the forest canopy. It sounds so far away. Attracted by this mysterious fairy musician you cross a wide forest alley... the sound stops. Suddenly, the surface of a pool trembles and is disturbed by small waves. Bathed in sunlight, a small world can be seen in this pool. Lying still, the palmate newt can hardly be spotted because of its earth coloured skin. Several large tadpoles move quickly and disappear between the twigs lying on the bottom. An almost transparent salamander larva, , hardly evokes the yellow and black colour of its nocturnal elder hidden not far away in a vole's burrow. On the edge, an inhabitant flees. Caught, frozen with terror, it shows its salamander coloured stomach. It is the mysterious fairy musician: the yellow bellied toad. ..
We can now find 13 species of amphibians in the Nature Park, all of them classified endangered species in France. 8 species of reptiles can also be found, including some of them endangered.
Birds

Viewed from the sky, the large lakes (5,000 ha) of the Forêt d'Orient Regional Nature Park, offer long distance migratory birds large stretches of water for a dream stay. Autumn or spring migrators , wintering birds, myriads of colourful birds, whether they be divers, geese, or ducks and cranes... find here a haven of peace. The lakes and the mud flats which appear after they're drained, the meadows, the ponds, the cultivated fields, offer indispensable food resource for birds. This site of international renown (it represents one of the world sites recognized by the RAMSAR convention), is the object of very particular attention (hunting forbidden ,control of human activity ).
During the winter, it welcomes, besides the thousands of water birds, such important hosts as the rare white tailed fish eagles. Otherwise, these lakes and their surroundings borders (forests, ponds and marshes) shelter, in the breeding season, many species (grebes, ducks...). So far, around 270 species of birds have been observed by local ornithologists.