EAZA Hornbill Management and Husbandry Guidelines

Most hornbills sometimes investigate the substrate, eat from the ground and use the
ground for sun or dust bathing, exposing themselves to attack.
Hornbills are sometimes also held with other hornbill species. Hybridization is a potential
problem, at least among congenerics. For example a male rhinoceros hornbill Buceros
rhinoceros and female great hornbill Buceros bicornis at Neopark Okinawa formed a
bond despite the presence of conspecifics of the opposite sex, and reared a hybrid
offspring (Uehara, 1990 in Takaki, 1996). A Jackson’s hornbill Tockus deckeni jacksoni
and African red-billed hornbill Tockus erythrorhynchus hybridized in a free-flight aviary
at San Antonio in the 1980’s. Subspecies need to be identified and kept separately; e.g.
Von der Decken’s hornbill Tockus d. deckeni and Jackson’s hornbill Tockus d. jacksoni
have probably hybridized freely in North American zoos (K. Smith, pers. comm).
An important consideration in housing hornbills with other species is availability of
unsuitable food items. It is highly likely that the hornbills will consume items higher in
iron than recommended for them if such items are available (see Section 3.1.6: Iron
storage disease).
4.2 Temperature
It is suggested for well-studied birds (e.g. chickens, pheasants, ducks and geese) that
colder weather (< 15°C) lowers sexual activity. Low temperatures also make it difficult
for the female to be able to maintain the appropriate temperature of the eggs during
incubation (Anderson Brown and Robbins, 1994).
Although exact tolerable minimum and maximum temperatures are not known for any
hornbill species, hornbills almost entirely range between 30° N to 30° S latitude, and
experience warm and fairly stable temperatures in their natural environment. Hornbills in
open, arid habitats experience greater daily temperature fluctuations than forest species,
but nevertheless average temperatures in such habitats are warmer than average
temperatures throughout most of Europe, and the air is drier. Like most tropical to subtropical
species, hornbills will suffer from frost-bite if held in freezing temperatures, and
their large casques and bills are particularly vulnerable. It is difficult to factor in the
effect of wind, precipitation and humidity into temperature management, nevertheless
these parameters certainly do influence how cold it is. The amount of shelter from wind
and amount of sun are also important. Age and condition of the birds influence their
temperature tolerance.
Managers should strive to duplicate temperature regimes that species are adapted to in
their native habitats (see Table 1.A) rather than holding them at the far lower
temperatures found throughout much of the northern hemisphere (Table 1.B). It can be
seen that annual temperature variation in in situ ranges of hornbill genera (Table 1 A) is
far smaller than annual variation in Russia and most of Europe as shown in Table 1.B.
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