Silent Evolution: The Rise of Tuskless Elephants in India

SAIKAT K BASU

Just like others, I love wildlife and biodiversity; and is concerned about their successful conservation. What prompted me to work on this particular article was a recent visit to the Indian Museum in Kolkata. I was amazed to locate the gigantic skeletons and tusks of Indian elephants displayed in the Zoology Gallery of the museum from the early 1900s and earlier. The monumental heights of these preserved skeletons and lengths of the tusks in display made me look into the past, searching answer for a question. Do current elephant populations in India demonstrating smaller average body heights and shorter tusks compared to their ancestors? Yes, there is some evidence suggesting that modern elephant populations in India are showing trends toward smaller body sizes and shorter tusks compared to their ancestors.

These changes are likely the result of both natural and human-influenced selection pressures, including:

1. Poaching and Human Conflict: Elephants with larger tusks are more likely to be targeted by poachers. Over time, this has led to increased survival and reproduction of elephants with smaller or no tusks. In some regions, tusklessness in Asian elephants (which already occurs naturally in some females and a minority of males) may be increasing.

2. Habitat Fragmentation: With reduced and fragmented habitats, smaller-bodied elephants may have a survival advantage, requiring less food and being more manoeuvrable in tight forested areas.

3. Historical Comparisons: Historical records, temple carvings, and colonial-era accounts often describe or depict larger elephants with prominent tusks.

Comparisons with skeletal remains and fossil records support the idea of a gradual size reduction over centuries, though data can be limited. These changes are more noticeable over generations and may vary by region. There’s still ongoing research on how significant and widespread these trends are in Indian elephant populations. There is compelling evidence that Indian elephant populations are exhibiting trends toward smaller body sizes and shorter or absent tusks compared to their ancestors. These morphological changes are influenced by a combination of human-induced pressures and environmental factors.

Tusklessness and Shorter Tusks

Regional Variations in Tusklessness: In North Eastern India, particularly in Assam and neighbouring states, studies have found that approximately 60% of male elephants are tuskless (known as "makhnas"). This contrasts sharply with southern India, where less than 10% of males are tuskless. The high prevalence of tusklessness in the Northeast is attributed to centuries of selective removal of tusked males for military use and ivory trade, leading to a genetic shift in the population.

Impact of Poaching on Tusk Size: In regions like Karnataka, rampant poaching between the 1970s and 1990s significantly reduced the number of large-tusked males. This selective pressure has led to a noticeable decrease in tusk size over generations. For instance, tusks seized before the 1980s often weighed over 80 kg and measured up to nine feet, whereas recent seizures rarely exceed 40 kg.

Body Size and Habitat Fragmentation: While direct studies on reductions in body size are limited, habitat fragmentation and loss have likely influenced elephant morphology. Between 1930 and 2013, India lost approximately 24.68% of its forest cover in elephant ranges, with core forest areas shrinking by nearly 40% . In the Western Ghats, over 16 lakh acres of elephant habitat were lost between 1960 and 2004, severing critical corridors and increasing human-elephant conflicts.

In fragmented landscapes like the Anamalai Hills, elephants have adapted by altering their habitat use patterns. They prefer riparian vegetation and rainforest fragments, especially during the day, and avoid large monoculture plantations and human settlements. These behavioural adaptations may favour smaller body sizes, which require less food and are more manoeuvrable in constrained environments.

Ongoing Research and Conservation Efforts: Researchers from institutions like the Indian Institute of Science are conducting genetic studies to understand the decline in tusk size and the increase in tusklessness. By analyzing DNA from tusks and blood samples, scientists aim to identify the genes responsible for tusk development and assess how these have changed over time.

Conservation initiatives, such as Project Elephant, have been launched to address these challenges. Established in 1992, Project Elephant focuses on habitat protection, mitigating human-elephant conflicts, and ensuring the long-term survival of elephant populations through a landscape-level approach.

Here are more detailed insights on regional patterns and conservation programs related to elephant tusk and body size changes in India:

1. Regional Details:

Northeast India (e.g., Assam, Arunachal Pradesh)

High tusklessness: Up to 60% of males are tuskless (makhnas)

Historical pressure: Elephants were captured for logging and military use; tuskers were preferred, reducing their numbers.

Genetic implications: This selective pressure likely passed on tuskless traits.

Southern India (e.g., Karnataka, Tamil Nadu, Kerala)

Tusked elephants more common, but with shorter tusks than in historical records.

Poaching impact: Intensive poaching in the 70s–90s significantly reduced large-tusked bull populations.

Recovery slow: Males with large tusks are now rare, and shorter tusks are increasingly common.

Western Ghats (Nilgiris, Anamalais, Periyar)

Habitat fragmentation has isolated elephant groups.

Adaptations: Elephants in fragmented forests may be evolving toward smaller body sizes due to limited forage and space.

2. Conservation Programs & Research

Project Elephant (MoEFCC, 1992–present)

Aims to:

· Protect elephant habitats and corridors.

· Reduce human-elephant conflict.

· Monitor populations scientifically.

· Includes monitoring tusk trends in states like Odisha and Jharkhand.

Genetic Research by Indian Institute of Science (IISc)

· Ongoing studies on genetic factors influencing tusklessness.

· Uses DNA from confiscated ivory and blood samples.

· Early results suggest heritable factors driving the change in tusk size.

NGO-Led Corridors Projects

NGOs like the Wildlife Trust of India and WWF have mapped 88 elephant corridors.

Efforts are being made to secure and restore these corridors, improving gene flow and habitat access.

While a detailed, up-to-date map is not readily available, existing studies provide insights into regional variations:

Northeast India (e.g., Assam, Arunachal Pradesh): Reports indicate that up to 60% of male elephants are tuskless, known locally as makhnas. This high prevalence is attributed to centuries of selective removal of tusked males for warfare and, more recently, ivory poaching.

Southern India (e.g., Karnataka, Kerala, Tamil Nadu): Tusklessness among male elephants is significantly lower, with estimates below 10%.

These patterns suggest that historical human activities have influenced the genetic makeup of elephant populations in different regions.

Summaries of Key Scientific Studies on Tusklessness

1. Historical Human Influence on Tusklessness in Northeast India

Findings: Centuries of selective capture of tusked elephants for military purposes and sustained ivory poaching have led to a higher proportion of tuskless males in Northeast India.

Implications: This long-term human intervention has likely caused genetic shifts favoring tusklessness in the region's elephant populations.

2. Genetic Basis of Tusklessness in African Elephants

Study: Research in Mozambique's Gorongosa National Park observed a rise in tuskless female elephants from 18.5% to 50.9% following intense poaching during the civil war.

Genetic Insights: The tuskless trait is linked to mutations on the X chromosome. Females with one copy of the mutation become tuskless, while males inheriting the mutation may not survive, explaining the scarcity of tuskless males.

Relevance to Indian Elephants: While this study focuses on African elephants, it underscores how intense poaching pressure can drive rapid evolutionary changes, a concept applicable to Indian elephant populations as well.

Tusklessness in Indian Elephants: Regional Insights

Assam: A High Prevalence Region

Makhnas (Tuskless Males): In Assam, tuskless males, locally known as makhnas,

Tusklessness Trends in Indian Elephant Populations

Tuskless Males (Makhnas): 64.5%

Tusked Males (Tuskers): 32.8%

Ganesh-type Males: 2.7%

These figures highlight the dominance of tuskless males in Assam's elephant population.

Kerala

Total Elephant Population (2023): Approximately 2,386 individuals

Makhnas: Data not explicitly available; however, the adult sex ratio is 1:2.56 (male:female), indicating a higher proportion of females.

Tamil Nadu

Total Elephant Population (2023): Approximately 3,063 individuals

Makhnas: Data not explicitly available; the adult sex ratio is 1:2.03 (male:female), suggesting a balanced male-to-female ratio.

While specific percentages for tuskless elephants in Kerala and Tamil Nadu are not easily available data, the provided figures offer insights into the general trends. Assam exhibits a significantly higher proportion of tuskless males compared to the southern states.