Glass Manja and Kite Wing Injuries: How Bird Rescue Teams in India Repair the Damage

Glass-coated manja is abrasive wire designed to cut a rival's kite string. At the speeds a black kite flies, up to 50 km/h in a glide, contact with a taut strand of manja acts less like a cut and more like a saw. The wire drags across the patagium, the thin membrane of skin that stretches from shoulder to wrist on a bird's wing, and through the flight feathers at the leading edge. The patagium is densely supplied with blood vessels and has almost no fat layer beneath it. A clean manja laceration bleeds heavily and fast.
The bone most commonly fractured is the coracoid or the ulna, depending on where the wire catches. The ulna runs along the trailing edge of the wing and anchors the secondary flight feathers. A fractured ulna does not just mean a broken bone, it means the bird cannot hold its wing in the aerodynamic shape required for lift. A kite with a fractured ulna that lands on the ground cannot take off again. It will stand, wing drooping, and wait.
Raptors have a skeletal structure built for lightness. Their bones are pneumatised, hollow, with internal struts, connected to the respiratory system. This is why a bird of prey weighing 900 grams can have a wingspan of 1.3 metres. The same hollowness that makes flight possible makes fractures complicated to stabilise. A splint applied with too much tension can compromise the blood supply running through the periosteum. Too little tension and the bone ends shift.
Black kites (Milvus migrans) are among the most studied urban raptors in the world. Research published in the journal Ibis has documented their extraordinary tolerance for human proximity, they nest on building ledges in Delhi, Mumbai, and Kolkata, scavenge alongside crows at municipal dumps, and fly in thermals directly above traffic. This behavioural flexibility is precisely why they suffer manja injuries at higher rates than other raptors: they share airspace with kite-flyers rather than retreating from it.

A further complication is stress physiology. When a wild raptor is handled, cortisol and adrenaline spike immediately. Prolonged handling without sedation can cause capture myopathy, a condition where sustained muscle exertion during restraint leads to cellular breakdown in muscle tissue. Rescuers trained in wildlife handling know that speed and calm handling are not just kindness; they are clinical requirements.
Wildlife rescue organisations, among them Wildlife SOS in Delhi and the Bombay Natural History Society's network of trained responders, follow a triage sequence when a manja-injured kite comes in. The bird is first wrapped loosely in a cloth to reduce visual stimuli and lower the stress response. The wound is cleaned with saline, not antiseptic solutions that damage tissue. Flight feathers that are bent but not broken are carefully straightened and, where necessary, imped, a technique borrowed from falconry in which a damaged feather shaft is spliced with a donor feather using a thin steel pin inserted into both quills.

Fractures are stabilised using figure-of-eight bandaging that immobilises the wing in a folded position against the body. This is not a cast in the human sense. The wing must be held in the bird's natural resting position, not extended, or the muscles will contract incorrectly during healing. For compound fractures, some facilities use intramedullary pins inserted into the hollow bone shaft under anaesthesia. Recovery time for an ulna fracture in a black kite runs between four and six weeks of cage rest, followed by progressive flight conditioning in a large aviary before release.
A manja injury left untreated for more than 12 hours carries a sharply elevated risk of infection and tissue necrosis. The patagium, once necrotic, cannot regenerate. A bird that loses a section of patagium cannot fly again, not because the bones are broken, but because the membrane that gives the wing its aerodynamic surface is gone. Rescuers in cities where manja use is heavy, Jaipur, Ahmedabad, Lucknow, and parts of Delhi, report that many birds arrive after bystanders have held them for a day or more, uncertain where to take them. That delay is the difference between a bird that returns to the sky and one that spends the rest of its life in an enclosure.

The injury that manja inflicts is not random. It concentrates on the birds most willing to live alongside us, and the repair, when it works, returns them to the exact thermals above the same neighbourhoods where the wire found them. The kite does not know it was saved. It simply rises again, and the city below it has no idea how close it came to losing one more bird to a string.