Bal-chatri () are traps designed to catch

birds of prey Birds of prey or predatory birds, also known as (although not the same as) raptors, are hypercarnivorous bird species that actively predation, hunt and feed on other vertebrates (mainly mammals, reptiles and smaller birds). In addition to speed ...

(raptors). The trap essentially consists of a cage baited inside with a conspicuously visible live rodent or small bird, with a series of monofilament nooses attached to the surface to snare the legs of a free-flying raptor that attempts to take the bait. The name is derived from the

Hindi Modern Standard Hindi (, ), commonly referred to as Hindi, is the Standard language, standardised variety of the Hindustani language written in the Devanagari script. It is an official language of India, official language of the Government ...

word used by trappers in India. Modified bal-chatri traps are also used for catching

shrike Shrikes () are passerine birds of the family Laniidae. The family is composed of 34 species in two genera. The family name, and that of the larger genus, '' Lanius'', is derived from the Latin word for "butcher", and some shrikes are also known ...

History

The bal-chatri originated in

East India East India is a region consisting of the Indian states of Bihar, Jharkhand, Odisha and West Bengal and also the union territory of the Andaman and Nicobar Islands. The states of Bihar and West Bengal lie on the Indo-Gangetic plain. Jharkhan ...

as a trap developed and used by falconers to catch suitable birds of prey to train for use in

hunting Hunting is the Human activity, human practice of seeking, pursuing, capturing, and killing wildlife or feral animals. The most common reasons for humans to hunt are to obtain the animal's body for meat and useful animal products (fur/hide (sk ...

. It consisted of a small, conical, cane

cage A cage is an enclosure often made of mesh, bars, or wires, used to confine, contain or protect something or someone. A cage can serve many purposes, including keeping an animal or person in captivity, capturing an animal or person, and displayi ...

, containing live lure birds to attract raptors, and covered with attached

horsehair Horsehair is the long hair growing on the Mane (horse), manes and Tail (horse), tails of horses. It is used for various purposes, including upholstery, brushes, the Bow (music), bows of musical instruments, a hard-wearing Textile, fabric called ...

noose A noose is a loop at the end of a rope in which the knot tightens under load and can be loosened without untying the knot. The knot can be used to secure a rope to a post, pole, or animal but only where the end is in a position that the loop can ...

s to entangle their feet. The term ''bal-chatri'' () has been mistranslated as "boy's umbrella", or "small umbrella", after their shape but is correctly translated to "hair umbrella" and refers to the nooses made of horse-hair anchored to the umbrella-like frame. Bal-chatris continue to be used by falconers, but are also used in ornithological research projects which require the capture of raptors for banding and other procedures, such as blood sampling.

Methodology and use

Contemporary traps are made of more modern materials, such as

wire file:Sample cross-section of high tension power (pylon) line.jpg, Overhead power cabling. The conductor consists of seven strands of steel (centre, high tensile strength), surrounded by four outer layers of aluminium (high conductivity). Sample d ...

mesh Medical Subject Headings (MeSH) is a comprehensive controlled vocabulary for the purpose of indexing journal articles and books in the life sciences. It serves as a thesaurus of index terms that facilitates searching. Created and updated by th ...

cages with nooses made of

nylon Nylon is a family of synthetic polymers characterised by amide linkages, typically connecting aliphatic or Polyamide#Classification, semi-aromatic groups. Nylons are generally brownish in color and can possess a soft texture, with some varieti ...

monofilament. The traps vary from 25–50 cm in diameter or length, with the nooses 4–12 cm in diameter. They are normally weighted to prevent them from being carried away by ensnared birds. The live lure, or bait, animals used for the trap are usually rodents such as house mice. The cage may have a double wall, or a removable roof or inner compartment, both to protect the bait animals from the raptors, and to prevent them damaging the nooses by chewing them. The traps are designed to be highly portable and may be deployed opportunistically from a slowly moving vehicle on a roadside when a hawk or falcon is sighted perch-hunting from a pole or utility line along a road. They may also be used near nesting sites in order to trap a breeding pair. Active traps require continuous monitoring. Users require proper training; there are ethical considerations and the need for experience in the use of bal-chatris to avoid harming, and minimizing temporary stress to, the bait animals and the raptors caught.

History

Methodology and use

References

Further reading