In the coastal district of Kollam, Kerala, a fundamental law of nature is being quietly rewritten under the glare of high-intensity LED floodlights. The Brahminy kite (Haliastur indus), a raptor traditionally defined by its "strictly diurnal" lifestyle, has been observed abandoning its sun-bound schedule to hunt and scavenge in the dead of night.
This behavioral shift, documented by citizen scientists and researchers, marks the first formal record of nocturnal foraging by this species in India. It serves as a stark illustration of how Artificial Light at Night (ALAN) is not merely an urban convenience but a powerful evolutionary force capable of altering the circadian rhythms, hunting strategies, and social structures of avian populations.
Main Facts: A Breach of Biological Protocol
The discovery centers on the Vaddy fishing harbour, a bustling maritime hub in Kollam city. Under normal circumstances, the Brahminy kite—easily identified by its chestnut plumage and contrasting white head and breast—retreats to its roost as the sun sets. However, recent observations have confirmed that a subset of the population is now active well past midnight, utilizing the harbor’s powerful lighting to exploit food sources that were previously the exclusive domain of nocturnal scavengers or were simply unavailable after dark.
Key findings from the recent study include:
- The Catalyst: High-intensity LED lighting in auction yards and on fishing vessels creates a "floodlit stadium" effect, providing enough visibility for raptors to identify prey.
- The Behavior: Kites were observed circling the harbour, diving to scoop fish from stationary boats, and snatching discards from the hands of fishermen between 9:00 PM and 12:30 AM.
- The Motivation: By hunting at night, these "bold" individuals avoid the intense daytime competition from hundreds of other kites, house crows, and feral dogs.
- The Scope: While currently localized, experts warn that this behavior could spread through social learning, potentially altering the ecological niche of the species in urban environments.
Chronology: From Routine Monitoring to a Scientific Breakthrough
The journey to this discovery began not in a laboratory, but through the persistent efforts of citizen science.
2019 – 2023: The Foundation of Observation
Polycarp Joseph, a district head for the Kerala State Annual Heronry Survey—a project under the Kerala Bird Monitoring Network (KBM)—began making annual visits to the Shaktikulangara and Vaddy harbours. His primary mission was to track the nesting habits of the little egret (Egretta garzetta). During these years, Joseph began visiting the harbours after dark to understand how light pollution affected nesting success, inadvertently setting the stage for his encounter with the kites.
February 5, 2024: The Midnight Discovery
At approximately 11:00 PM, while conducting a survey at the Vaddy fishing harbour, Joseph witnessed an unexpected sight. Three Brahminy kites were actively maneuvering through the air, performing hunting dives that are typically seen only during peak daylight hours. He remained on-site until 12:30 AM, recording the birds as they snatched fish from the decks of artisanal vessels.
February – March 2024: Establishing a Pattern
To ensure the initial sighting wasn’t a fluke, Joseph returned on subsequent nights. He consistently observed one or two kites scavenging between 9:00 PM and 11:00 PM. Conversations with local artisanal fishermen revealed that this was not a one-off event; the fishermen had been seeing the "midnight hunters" for some time, though they had not realized the scientific significance of the observation.
Mid-2024: Publication and Peer Review
Recognizing the importance of the find, Joseph collaborated with a research team to document the behavior. Their findings were recently published in the Journal of Ornithology, providing the scientific community with its first documented case of nocturnal foraging in Brahminy kites within the Indian subcontinent.
Supporting Data: The Mechanics of Urban Adaptation
The shift from diurnal to nocturnal activity is not a random occurrence but a calculated response to environmental cues and competitive pressures.
The Role of ALAN (Artificial Light at Night)
Research indicates that billions of organisms are currently responding to ALAN. Nishant Kumar, head of the New Delhi-based think tank Thinkpaws, explains that ALAN affects "cue-outcome mapping." In the case of Vaddy, the kites have learned that the presence of bright LED lights (the cue) predicts the availability of easy food (the outcome) with minimal competition.
Vision and Predation
While Brahminy kites are diurnal, "Old World" kites (a group that includes both Brahminy and Black kites) possess relatively good low-light vision. This physiological "pre-adaptation" allows them to push the boundaries of their active hours. In Delhi and parts of Europe, Black kites have been seen foraging near landfills as early as 5:00 AM or as late as 9:00 PM. The extreme shift to 12:30 AM in Kollam, however, represents a significant extension of this plasticity.
The Competitive Edge
The Vaddy harbour area is home to an estimated 500–600 Brahminy kites. During the day, these birds must compete with:
- Hundreds of Black kites (Milvus migrans).
- Thousads of House crows.
- Large numbers of feral dogs.
- Aggressive little egrets.
By shifting to a nocturnal schedule, a small subset of the population—often those that are more "risk-prone" or perhaps malnourished and desperate—can access high-quality protein (mackerels and sardines) without the energetic cost of defending their catch from a dozen other scavengers.
Official Responses and Expert Insights
The discovery has prompted a wider discussion among ornithologists and environmental scientists regarding the long-term impacts of light pollution on biodiversity.
Nishant Kumar (Thinkpaws):
Kumar highlights that this behavior is a form of "unusual resource exploitation." He notes that while it may start with a few bold individuals, "it may also spread in the region as other kites and opportunistic birds socially learn this behavior from them." This suggests that we may be witnessing the birth of a new urban behavioral tradition among Indian raptors.
Sayuri Díaz-Palma (Jagiellonian University):
Díaz-Palma, a lead author on a meta-analysis of light pollution in Ecology Letters, provides a broader physiological context. Her research, which analyzed 36 studies across 30 bird species, found that ALAN consistently leads to:
- Activity Extension: Birds staying active long after sunset.
- Sleep Disruption: A clear physiological impact that disrupts circadian rhythms.
- Metabolic Shifts: Changes in melatonin production and immune function.
"Our results showed that stronger light intensities were generally associated with activity shifts and sleep disruption," Díaz-Palma stated. She suggests that the powerful LED lighting at Vaddy is the primary facilitator for this "unnatural" foraging.
Implications: The Future of the Urban Sky
The nocturnal Brahminy kites of Kollam are a symptom of a larger, global environmental transformation. As India continues to urbanize and modernize its coastal infrastructure, the "darkness" of the night is rapidly disappearing.
1. Ecological Traps and Physiological Stress
While the kites gain a short-term advantage by finding food more easily, the long-term costs remain unknown. Constant exposure to ALAN can lead to "accelerated aging" and weakened immune systems due to the lack of restorative sleep. If the kites are not getting adequate rest, their ability to successfully breed or migrate could be compromised, turning the well-lit harbour into an "ecological trap."
2. Habitat-Specific Behavioral Evolution
Interestingly, the behavior is not universal. At the Shaktikulangara harbour, just 8 kilometers away, the kites remain diurnal. Researchers believe this is due to the nature of the catch. Shaktikulangara hosts large trawlers bringing in heavy fish like tuna, which are too large for a kite to carry. Furthermore, the "excessive noise pollution" from large industrial engines at Shaktikulangara may act as a deterrent, whereas the smaller, quieter artisanal boats at Vaddy provide a more inviting environment for the raptors.
3. The Need for "Dark Sky" Policies
The study underscores the fact that light pollution is an understudied component of anthropogenic environmental impact. While air and water pollution receive significant policy attention, "light spill" is often ignored. Experts argue that documentation like Joseph’s should encourage urban planners to consider "bird-friendly" lighting—such as motion-activated lights or shielded fixtures that direct light downward rather than into the sky.
4. The Power of Citizen Science
Finally, this case highlights the vital role of citizen science in modern ecology. Professional researchers cannot be everywhere at once, especially at 1:00 AM in a fishing harbour. It was the curiosity and dedication of a local volunteer, Polycarp Joseph, that brought this phenomenon to light.
As the sun sets over the Arabian Sea and the LED floodlights of Vaddy flicker to life, the Brahminy kites taking to the wing are a reminder that nature is not static. It is a flexible, responding force, constantly trying to find a foothold in a world that never sleeps. The challenge for conservationists moving forward will be ensuring that in our quest to light up the night, we don’t inadvertently extinguish the biological rhythms that have sustained these species for millennia.
