Among the following Tiger Reserves, which one has the largest area under "Critical Tiger Habitat" ?

1. Project Tiger & The NTCA (basic)

Welcome to our first step in mastering tiger conservation! To understand how we manage tiger reserves today, we must go back to April 1, 1973. At that time, India’s tiger population had plummeted from an estimated 40,000 at the turn of the century to fewer than 2,000. In response, the Government of India launched Project Tiger, a pioneering conservation program aimed at ensuring a viable population of tigers for their scientific, ecological, and cultural values Environment and Ecology, Majid Hussain (Access publishing 3rd ed.), BIODIVERSITY, p.43. The tiger is considered an "umbrella species"—by protecting the tiger and its vast habitat, we automatically protect thousands of other species of flora and fauna in that ecosystem.

Initially, the project began with just nine tiger reserves. Today, that footprint has expanded significantly to over 50 reserves across 18 states, covering more than 71,000 sq. km INDIA PHYSICAL ENVIRONMENT, Geography Class XI (NCERT 2025 ed.), Natural Vegetation, p.50. A crucial turning point occurred in 2006. Realizing that tiger conservation needed stronger legal and professional backing, the Wildlife (Protection) Act of 1972 was amended to create the National Tiger Conservation Authority (NTCA) Environment, Shankar IAS Academy (ed 10th), Conservation Efforts, p.228. The NTCA is a statutory body under the Ministry of Environment, Forest and Climate Change (MoEFCC), providing the oversight and standardized guidelines that all tiger reserves must follow.

One of the core management strategies under this framework is the identification of Critical Tiger Habitats (CTH). These are the "core" areas of tiger reserves which are required to be kept inviolate (free from human disturbance) based on scientific evidence to ensure tiger breeding and long-term survival. Outside this core lies the "buffer" zone, where some human activity is managed to allow for co-existence Environment and Ecology, Majid Hussain (Access publishing 3rd ed.), BIODIVERSITY, p.45.

Sources: Environment and Ecology, Majid Hussain (Access publishing 3rd ed.), BIODIVERSITY, p.43, 45; INDIA PHYSICAL ENVIRONMENT, Geography Class XI (NCERT 2025 ed.), Natural Vegetation, p.50; Environment, Shankar IAS Academy (ed 10th), Conservation Efforts, p.228

2. Zoning: Critical Tiger Habitat (Core) vs. Buffer (basic)

To understand how India protects its national animal, we must look at the zoning strategy of a Tiger Reserve. Under the Wildlife Protection Act (WPA), 1972, a Tiger Reserve is not just one uniform block of forest; it is divided into two distinct functional layers: the Critical Tiger Habitat (Core) and the Buffer Zone. This 'zoning' is essential because tigers require vast, undisturbed territories to hunt and breed, but they often live in landscapes shared with human communities. Environment, Shankar IAS Academy, Conservation Efforts, p.227

The Critical Tiger Habitat (CTH), also known as the Core Area, is the 'sanctum sanctorum' of the reserve. It is identified based on scientific evidence to be kept inviolate—meaning it should be free from all human disturbances, including permanent settlements and commercial exploitation. The primary goal here is to provide a safe, stress-free environment for tiger populations to thrive. In contrast, the Buffer Zone is the peripheral area that surrounds or adjoins the core. It acts as a 'shock absorber' for the core area. In the buffer, a lesser degree of habitat protection is required, and the focus shifts toward co-existence. Environment and Ecology, Majid Hussain, BIODIVERSITY, p.34

Feature	Critical Tiger Habitat (Core)	Buffer Zone
Legal Status	Inviolate (No human interference)	Multiple-use area
Permitted Activities	Strictly limited to scientific research and monitoring.	Sustainable grazing, fishing, eco-tourism, and collection of non-timber forest produce.
Objective	To ensure an undisturbed breeding ground for tigers.	To provide habitat supplement and ensure the integrity of the core while supporting local livelihoods.

The management of the Buffer Zone is particularly clever because it involves local communities in conservation. By allowing activities like limited recreation and tourism, it reduces the economic dependency of locals on the resources inside the core area. Environment, Shankar IAS Academy, Protected Area Network, p.220 This dual-zone approach ensures that while the tiger has its 'private home' (Core), the 'neighborhood' (Buffer) is managed to prevent conflicts and support regional biodiversity.

Sources: Environment, Shankar IAS Academy, Conservation Efforts, p.227; Environment and Ecology, Majid Hussain, BIODIVERSITY, p.34; Environment, Shankar IAS Academy, Protected Area Network, p.220

3. Notification Process of Tiger Reserves (intermediate)

The notification of a Tiger Reserve is a formal legal process governed by the Wildlife (Protection) Act (WPA), 1972. While Project Tiger began as an administrative scheme in 1973, it was the 2006 amendment to the WPA that gave Tiger Reserves a statutory (legal) status Shankar IAS Academy, Conservation Efforts, p.227. The process follows a specific hierarchy: the State Government holds the power to notify an area as a Tiger Reserve, but they can only do so upon the recommendation of the National Tiger Conservation Authority (NTCA). This ensures that local administrative control is balanced with national conservation standards.

Under Section 38V of the Act, a Tiger Reserve must consist of two distinct zones created through a scientific identification process. The Critical Tiger Habitat (CTH), also known as the Core Area, is identified based on scientific evidence to be kept 'inviolate'—meaning it should be free from human disturbance to allow for tiger dispersal and breeding. Surrounding this is the Buffer or Peripheral Area, which serves as a transition zone to provide habitat supplement to the core and allows for a higher degree of co-existence between wildlife and human activity.

Feature	Critical Tiger Habitat (Core)	Buffer/Peripheral Area
Objective	Strict conservation; kept inviolate.	Co-existence; habitat protection.
Human Activity	Highly restricted; relocation often required.	Regulated activity; ensures livelihood security.
Legal Basis	Identified by experts/scientific evidence.	Established in consultation with Gram Sabhas.

A vital aspect of this notification process is the protection of tribal rights. Before any area is notified or any relocation occurs, the consent of the Gram Sabha and the completion of the settlement of rights are mandatory. This ensures that conservation does not come at the cost of the fundamental rights of forest-dwelling communities Shankar IAS Academy, Protected Area Network, p.211.

Sources: Shankar IAS Academy, Conservation Efforts, p.227; Shankar IAS Academy, Protected Area Network, p.211

4. Connected Concept: Critical Wildlife Habitats (FRA) (intermediate)

To truly master tiger reserve management, we must distinguish between two terms that sound identical but belong to different laws: Critical Tiger Habitats (CTH) and Critical Wildlife Habitats (CWH). While CTHs are governed by the Wildlife Protection Act (WLPA), 1972, the concept of Critical Wildlife Habitats arises from the Scheduled Tribes and Other Traditional Forest Dwellers (Recognition of Forest Rights) Act, 2006, commonly known as the FRA Shankar IAS Academy, Indian Forest, p.165. The goal of a CWH is to identify specific areas within National Parks and Sanctuaries that must be kept inviolate—meaning free of human presence—to ensure the long-term survival of threatened species Majid Hussain, Biodiversity, p.29.

The beauty of the CWH provision is how it balances ecology with human rights. Unlike older conservation models that sometimes led to forced evictions, the FRA mandates a rigorous process. Before an area is declared a CWH, the individual and community forest rights of the local people must be fully recognized and settled Shankar IAS Academy, Indian Forest, p.165. Furthermore, it must be scientifically established that human presence is causing irreversible damage to the wildlife, and most importantly, the Gram Sabha must give its free, prior, and informed consent to any proposed resettlement M. Laxmikanth, World Constitutions, p.746.

Understanding the difference between these two "Critical" areas is vital for any civil services aspirant:

Feature	Critical Tiger Habitat (CTH)	Critical Wildlife Habitat (CWH)
Governing Act	Wildlife Protection Act, 1972 (as amended in 2006)	Forest Rights Act (FRA), 2006
Scope	Specifically for Tigers in Tiger Reserves	Any species in National Parks/Sanctuaries
Key Authority	National Tiger Conservation Authority (NTCA)	Ministry of Environment, Forest and Climate Change (MoEFCC)

Sources: Environment, Shankar IAS Academy, Indian Forest, p.165; Environment and Ecology, Majid Hussain, BIODIVERSITY, p.29; Indian Polity, M. Laxmikanth, World Constitutions, p.746; NCERT, Contemporary India II, Nationalism in India, p.30

5. Connected Concept: Eco-Sensitive Zones (ESZ) (intermediate)

To understand Eco-Sensitive Zones (ESZ), we must first look at the landscape of conservation. Imagine a National Park or a Tiger Reserve as a strictly protected 'inviolate' island. If we allow heavy industry or massive mining right up to the park's boundary, the sudden change would cause an 'ecological shock' to the wildlife. Therefore, ESZs are designed as 'shock absorbers' or transition zones between areas of high protection and areas of intensive human activity. While the Wildlife (Protection) Act, 1972 focuses on the management within the protected areas, the legal 'teeth' for ESZs actually come from the Environment (Protection) Act, 1986 Environment and Ecology, Majid Hussain (Access publishing 3rd ed.), Major Crops and Cropping Patterns in India, p.88. Under Section 3 of this 1986 Act, the Central Government can restrict areas in which any industries or operations shall not be carried out or shall be carried out subject to certain safeguards.

The primary goal of an ESZ is to regulate human activity so that it doesn't negatively impact the fragile ecosystem of the core area. For instance, in sensitive coastal regions, these zones might protect mangroves, coral reefs, and nesting grounds to maintain the geomorphological integrity of the coast Environment, Shankar IAS Academy (ed 10th), Aquatic Ecosystem, p.54. In the context of Tiger Reserves, these zones ensure that the forest doesn't become an isolated patch, allowing for better movement and genetic flow of tigers across the wider landscape. The extent of an ESZ is generally up to 10 kilometers around a protected area, though this can be extended if there are specific ecological corridors that need protection.

Activities within an ESZ are categorized into three distinct tiers to balance conservation with local livelihoods:

Category	Description/Examples
Prohibited	Commercial mining, setting up sawmills, highly polluting industries, and major hydroelectric projects.
Regulated	Felling of trees, establishment of hotels/resorts, drastic change of agriculture system, and widening of roads.
Permitted	Ongoing agricultural or horticultural practices by local communities, rainwater harvesting, and organic farming.

Sources: Environment and Ecology, Majid Hussain (Access publishing 3rd ed.), Major Crops and Cropping Patterns in India, p.88; Environment, Shankar IAS Academy (ed 10th), Aquatic Ecosystem, p.54

6. Profile: Nagarjunsagar-Srisailam Tiger Reserve (exam-level)

The Nagarjunsagar-Srisailam Tiger Reserve (NSTR) is a crown jewel of India’s conservation efforts, distinguished primarily by its sheer scale. Located in the Nallamala Hill ranges of Andhra Pradesh, it is recognized as the largest tiger reserve in India Geography of India, Natural Vegetation and National Parks, p.45. Geographically, the landscape is dominated by the Krishna River, which cuts through the reserve, creating deep gorges and supporting a rich mosaic of dry deciduous forests and scrublands. This rugged terrain provides an ideal, contiguous habitat for not just the Bengal Tiger, but also leopards, dholes (wild dogs), and the rare honey badger. From a management perspective, the most critical aspect of NSTR is its status regarding Critical Tiger Habitats (CTH). Under the Wildlife Protection Act (WPA), 1972, tiger reserves are divided into a 'core' and a 'buffer' area. The core area, or the CTH, is required by law to be kept 'inviolate'—meaning it must be free of human habitation and commercial exploitation to ensure the long-term survival of the species. NSTR holds the record for the largest notified CTH in India, spanning approximately 2,595.72 sq. km. This makes it a vital sanctuary where tigers can roam across vast distances without human interference. Historically, the reserve was even larger before the bifurcation of Andhra Pradesh. Following the creation of Telangana, a portion of the original reserve was reorganized as the Amrabad Tiger Reserve. Despite this division, the NSTR remains a massive ecological corridor that connects the Eastern Ghats, facilitating genetic diversity among wildlife populations across the region Environment, Environment Issues and Health Effects, p.430.

Sources: Geography of India, Natural Vegetation and National Parks, p.45; Environment, Environment Issues and Health Effects, p.430

7. Ranking Tiger Reserves: Area & Density (exam-level)

When we discuss the ranking of Tiger Reserves in India, we look at two primary metrics: Spatial Extent (Area) and Population Concentration (Density). Understanding these rankings requires a distinction between the Total Area (which includes the buffer zones) and the Critical Tiger Habitat (CTH), also known as the core area. Under the Wildlife Protection Act, 1972, CTHs are notified based on scientific evidence to be kept 'inviolate' for tiger conservation, meaning they are managed primarily for wildlife with minimal human interference.

In terms of sheer size, Nagarjunsagar-Srisailam Tiger Reserve (spanning Andhra Pradesh and Telangana) holds the title of the largest tiger reserve in India Geography of India, Natural Vegetation and National Parks, p.45. It features a massive Critical Tiger Habitat of approximately 2,595 sq. km within the Nallamala forest range. Conversely, the Bor Tiger Reserve in Maharashtra is recognized as the smallest, covering a total area of only about 138.12 sq. km Geography of India, Natural Vegetation and National Parks, p.46. These variations in size are often dictated by the topography and the contiguity of the forest landscape.

However, a large area does not always equate to a high number of tigers. This brings us to Tiger Density — the number of tigers per 100 sq. km. While reserves like Nagarjunsagar-Srisailam are vast, they may have lower densities compared to smaller, prey-rich parks. Jim Corbett Tiger Reserve in Uttarakhand consistently records the highest tiger density in India, followed by reserves like Kaziranga and Orang in Assam. This high density is typically driven by an abundance of alluvial grasslands and high concentrations of ungulate prey (like deer and wild boar).

Metric	Rank: Highest/Largest	Rank: Lowest/Smallest
Total Area / CTH	Nagarjunsagar-Srisailam (AP/Telangana)	Bor (Maharashtra)
Tiger Density	Jim Corbett (Uttarakhand)	Varies (often reserves with high human disturbance or low prey)

Sources: Geography of India, Natural Vegetation and National Parks, p.45; Geography of India, Natural Vegetation and National Parks, p.46

8. Solving the Original PYQ (exam-level)

Now that you have mastered the legal framework of the Wildlife Protection Act, 1972, this question challenges you to apply the concept of Critical Tiger Habitat (CTH) to India's physical geography. As you learned, the CTH represents the inviolate core area of a tiger reserve, where conservation is prioritized over all other activities. This question isn't just testing memory; it’s testing your ability to distinguish between a reserve's general reputation and its actual notified land-use scale as defined by the National Tiger Conservation Authority (NTCA).

To arrive at the correct answer, you must look toward the massive, contiguous landscape of the Nallamala forest range. While many aspirants are tempted to pick more famous reserves, the correct choice is (C) Nagarjunsagar-Srisailam. This reserve holds the title of the largest CTH in India, spanning approximately 2,595.72 sq. km. When reasoning through such questions, always remember that the legal notification of the core is the deciding factor, and in this case, the vastness of the Andhra Pradesh landscape far exceeds the core zones of its counterparts in the north or east.

UPSC frequently uses "fame traps" to distract students. For instance, Corbett and Ranthambore are iconic for tiger sightings, but their Critical Tiger Habitats are relatively small (821.99 sq. km and 1,113.36 sq. km respectively). Even the Sunderbans, despite its global ecological stature, has a CTH of about 1,699.62 sq. km—large, but still significantly smaller than Nagarjunsagar-Srisailam. Don't let a reserve's popularity in tourism mislead you; instead, focus on the quantitative data regarding notified land zones found in the NTCA Annual Reports.