What is Jatinga bird mystry? Is it related with bird migration ? Explain.

The Jatinga Phenomenon: An Overview

The Jatinga bird mystery primarily occurs during the months of September to November, coinciding with the southward migration of birds from Central Asia and the Himalayas. The phenomenon is most pronounced on foggy and moonless nights. Birds, particularly those migrating, are attracted to lights in the village, and instead of flying over them, they circle around and eventually plummet to the ground, often resulting in their death or making them vulnerable to capture. The species affected include various types of warblers, kingfishers, herons, and other migratory birds.

Hypotheses Linking to Bird Migration

Initially, the phenomenon was linked to the disorientation of migratory birds. Several theories proposed that:

• Magnetic Anomalies: The region is believed to have some degree of magnetic anomalies, potentially disrupting the birds’ navigational abilities, especially during cloudy nights when they rely on the Earth’s magnetic field.
• Strong Winds: The area experiences strong downdrafts and winds, which could push birds off course, particularly those already disoriented by lights.
• Migration Fatigue: Migratory birds are often exhausted after long flights. The bright lights might attract them, and their weakened state could prevent them from correcting their flight path.
• Traditional Hunting Practices: Early reports suggested that villagers used lights to attract and kill birds for food, though this has largely been debunked as the primary cause.

Scientific Explanations & Current Understanding

While the migration-related theories hold some merit, current scientific understanding points towards a combination of factors, with counter-illumination camouflage disruption being the most prominent:

• Counter-illumination Disruption: Many birds use counter-illumination camouflage, where they emit a faint glow from their underside to blend with the brighter sky above, making them less visible to predators below. Artificial lights disrupt this camouflage, making the birds appear more visible and potentially causing them to lose their sense of direction.
• Visual Confusion: The bright lights create a visual distraction, causing birds to become confused and lose their navigational cues.
• Local Geography: Jatinga is situated in a valley, and the surrounding hills create a funnel effect, concentrating the birds in a specific area.

Studies have shown that the phenomenon is not limited to migratory birds; local resident birds are also sometimes affected, suggesting that the light-induced disorientation is a significant factor. Furthermore, the use of bird-friendly lighting and reducing light pollution in the area have shown some positive results in mitigating the problem.

Geographical Context

The Dima Hasao district of Assam, where Jatinga is located, is characterized by hilly terrain and dense forests. This geographical setting plays a role in the concentration of birds during migration. The valley location and the presence of fog contribute to the visibility of artificial lights and the disorientation of birds. The area lies on a major migratory route for birds traveling between the breeding grounds in the Himalayas and the wintering grounds in Southeast Asia.