With a rich and diverse variety of flora and fauna, this sub-continent is considered ornithologist paradise, almost every state of Indian union has a Sanctuary or Park. All across the country are wildlife sanctuaries whose areas extend over several thousand of square kilometers from where wildlife can be observed in their natural surroundings. 
Each sanctuary supports several species of wildlife, being well known for one particular species. In some cases, there are rare or even endangered species. 

Thus, the Gir Forest in Gujarat is the only surviving home of the Asiatic lion, Manas and Kaziranga in Assam have significant population of one horned rhinos, Periyar in Kerala is best known for wild elephant viewing. Thamin deer at Keibul Lamjao national park in Manipur, Hangul or Kashmir Stag at Dachigam, Srinagar and Black Buck at Velavadhar in Gujarat are the only home of these species. 

Project tiger initiated in 1973, identified major areas inhabited by tigers. Bhandavgarh and Kanaha sanctuaries in Madhya Pradesh, Sariska and Ranthambore in Rajasthan and Corbett Park and Dudhwa in Uttar Pradesh are some of the countries best known tiger reserves. Sunderbans National Park is mostly estuarine mangrove forest is the habitat of nearly two hundred Royal Bengal Tigers. Other species at these places include panthers and several species of deer and antelope.

Bharatpur, a five hours drive from Delhi, has the largest bird sanctuary in Asia. Water birds, that migrate from other parts of the country include herons, ibis, pelicans, painted storks, spoonbills, egrets and open billed storks. Various species of ducks and gees migrate from Russia. These include brahminy ducks and the endangered Siberian crane. 

The best time for a visit is from October to March when the weather is relatively pleasant. July - August is the breading season for the resident species.