standardization of records keeping in indian zoos - Central Zoo ...

the tag type to read the identification. However, a universal tag reader is also available
now. PIT Tags may wander under an animal‟s skin, especially on large mammals.
The transponders are rod shaped and are available in several sizes, ranging from 2mm
in diameter by 10mm long to 3.5mm in diameter by 30 mm long. The larger the
transponder, the greater the distance from which it can be read. The read range for all
of the currently available transponders is very limited, ranging from less than 8cm for
the 2 by 10mm transponders (Fagerstone and Johns 1987, Thomas et al. 1987) to
approximately 16cm for the 3.5 by 30 mm transponders. As the larger transponder
sizes are unacceptable for many mammals and increase the read range by only
centimeters, the smaller 2 by 10 mm transponder are recommended.
Encased in glass, the transponder can be implanted in the muscle or under the
skin. Transponders are packed in sterilized 12 gauge implanter needles. At the
Wildlife conservation park we implant mammals subcutaneously. After the implant
site is cleaned with alcohol, the hair is spread to expose the skin shaving the site is not
recommended). The implanter needle is placed level-up at an approximately 45 o angle
to the skin surface, and the skin is pierced with the needle. The implanter needle is
then positioned almost parallel to the skin, and the transponder is injected under the
skin surface, and the skin is pierced with the needle. The implanter needle is then
positioned almost parallel to the skin, and the transponder is injected under the skin.
The needle should be carefully withdrawn and finger pressure applied to the
implantation site for approximately 30 seconds. The implantation site then should be
scanned by the reader to verify both successful implantation and the transponder‟s
unique code. Occasionally the needle will leave a wound; if it does, the wound should
be sealed with an adhesive skin bond.
When this technique has been properly applied, neither infection nor migration
of the transponder implants has been a problem (Fagerstone and Johns 1987; Thomas
et al.1987; Ball et al. 1991).
The most convenient site for the implantation of a microchip is at the base of
the left ear for large mammals and between the shoulder blades to the left of centre for
small mammals and for animal species with thick skin such as the slow loris,
Nycticebus coucang, and Rock hyrax, Procavia capensis, on the left hip.
Recently, after reviewing the available transponder systems for performance,
availability, and cost, the IUCN/CBSG working Group on permanent Animal
Identification recommended that the international zoo community adopt the
Trovan/A.E.G (125 KHz) transponder system (IUCN/CBSG 1991).
The major disadvantages of transponder identification are as follows:
I. The equipment is comparatively expensive to other marking equipments.
II. Transponders are not legible at a distance; Restraint of the animal is usually
required to read them.
III. Transponder permanence needs verification, early transponder studies were done
on transponders encased in plastic. Because of leakage into the plastic case, their
failure rates were 16% (Thomas et al, 1978) and 30% (Fagerstone and Johns 1987) in
fairly short-term studies (< 1 year). Transponders are now being manufactured with
glass casings and theoretically should not have the leakage problem. However,
experience to date at the Wildlife Conservation Park and end elsewhere (Taylor,
Emerson, and Wagner 1993) suggests that a failure rate of about 5% can still be
expected, so one should not depend solely on transponders for identification of
individual animal.
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