EAZA Hornbill Management and Husbandry Guidelines

2 Captive population management
2.1 Identification
Conclusions on this topic were made during the International Hornbill Workshop 1997 in
Malaga (Spain), and were originally summarized by Christine Sheppard.
Large hornbills are rarely individually-marked in zoos because they are dimorphic and
usually kept in pairs. However, if future, more intensive, population management results
in more hornbill exchanges between institutions, all individuals should be readily
identifiable. Transponders are useful, but can migrate or fail, and are unreadable unless a
bird is very near the transponder reader. There have been no reports of significant
problems with any type of metal leg band. Therefore it is recommended that these two
marking systems, bands and transponders, are used simultaneously.
Transponders should be implanted in a hornbill’s right pectoral muscle. If possible, a
second transponder should be implanted as a back up. The second transponder should be
implanted in the left pectoral muscle as two transponders implanted in the same site can
give hybrid readings. All hornbills should be ringed below the tarsometatarsal joint with
metal bands engraved with identification numbers. Males should preferably be banded on
the right, females on the left. While “closed” rings or bands, which cannot be removed
without being destroyed, should ideally be used, other bands can be used when necessary.
Young hornbills should be banded as soon as possible without disruption to management.
Transponder and band numbers and site of placement on the body should be included in
the bird's records.
A comprehensive list of ring sizes and appropriate age to fit closed rings should be
compiled for a future edition of hornbill guidelines or as a supplement to the guidelines.
2.2 Morphology and sex determination
Males are equal to, or up to 17% heavier, than females in mass. Wing length of males is 1
to 21 % greater and bill length 8 to 30% greater than in females. Male casques are always
larger than female casques. The bill and the casque probably have a role in
communicating age, sex and status of an individual in conjunction with changes in eye,
skin and plumage coloration (Kemp, 1995). Examination of the degree of dimorphism in
various features through out the hornbills (Kemp 1995) suggests that species that are
highly dimorphic in coloration are often not extremely dimorphic in casque volume,
while many that are very dimorphic in casque volume are relatively monomorphic in
coloration.
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