A bir is a preserved patch of woodland, usually a princely hunting reserve, kept when the country around it was cleared. Punjab has a number of them and they are the state's oldest surviving tree cover outside the Shivaliks.
Bir Bhadson, Bir Bhunerheri, Bir Moti Bagh, Bir Aishvan and Bir Gurdialpura in Patiala district; Bir Talab near Bathinda; Bir Baba Buddha Sahib at Thatta in Amritsar district.
Several are now wildlife sanctuaries. They hold blackbuck, nilgai, hog deer and a bird population out of proportion to their size, because there is nowhere else.
Bir Baba Buddha Sahib is a different case: it is the forest where Baba Buddha Ji grazed cattle and it was preserved for that reason rather than for hunting.
The princely states preserved these for their own sport and the result is that Punjab's only fragments of pre-agricultural vegetation exist because a maharaja wanted somewhere to shoot.
They are small, isolated and surrounded by intensive agriculture, which is the worst possible configuration for anything living in them.
A bir is a reserved wood, usually attached to a shrine, a state's hunting ground or a village's common land, and they are what is left of the natural vegetation of the plain.
Bir Aishvan, Bir Bhunerheri, Bir Moti Bagh, Bir Gurdialpura and others in the Patiala country were the state's shikargahs and are now reserved forests.
Together they are a very small area. Punjab has the lowest forest cover of any Indian state and most of what it has is either Shivalik hillside or a bir.