EEP Crowned pigeon number 4

EEP STUDBOOK CROWNED PIGEONS
Arnhem Zoo is famous about its huge greenhouse (135,000 m²) which also houses two pairs
of Goura victoria. In this enormous enclosure, opened in 1988 and called Burgers’ Bush, the
crowned pigeons have possibilities to conduct every kind of behaviour they want: there are all
kinds of substrate available, all kinds of branches, all kinds of vegetation, some parts are
accessible to visitors while others are not. There are hundreds of other animals: mammals,
birds, fish, reptiles, amphibians and invertebrates. There are no prefab nests available, but as
soon as the bird keepers notice that a pair of crowned pigeons has found a suitable place, they
assist in placing a solid basis for the nest.
In the breeding area of the zoo another pair of Goura victoria is housed. This pair used to live
in Burgers’ Bush, but they were too aggressive, especially towards children. Now they are
housed behind the scenes in a former walk-through enclosure. This indoor aviary measures
about 15 x 5 meter and is about 3.5 meter high. The roof consists of frosted glass, which
provides at least a lot of light. There is no artificial light. There is sand as well as mould, a
rather large but deep pond, a lot of plants with branches to sit on, some additional perches, a
nest and also breeding pairs of other birds: Aratinga aurea, Burhinus magnirostris, Tauraco
leucolophus and Amaurornis phoenicurus.
In total eight pairs of crowned pigeons in seven enclosures were studied. These enclosures
can be divided (looking at size and furnishing) into three categories:
(1) The very small enclosure with very little possibilities behind the scenes in Rotterdam Zoo
(this cage does not exist any more)
(2) The restricted environments of Amsterdam Zoo (two aviaries), Alphen a/d Rijn Birdpark
(two cages), and the breeding center of Arnhem Zoo.
(3) The very large and very rich environment of Burgers’ Bush.
Methods
The study comprised two parts. In the observational part the time budgets of the eight pairs of
crowned pigeons in the seven enclosures are studied and compared. In the experimental part
in some enclosures the perches (three enclosures) or the substrate (one enclosure) were
changed irregularly to determine the preferences of the birds.
In the observational part the time budget of eight pairs of crowned pigeons is registered
during four days (about 24 hours). The behaviour was registered every minute using scan
sampling; instantaneous sampling. In this way per bird 24 * 60 = 1440 registrations were
made. Only in Burgers’ Bush observations were carried out during 5 days (40 hours) in order
to get enough data. Because of the size of the enclosure it was not possible to register the
behavior of every bird every minute; therefore in Burgers’ Bush the behavior is recorded only
every 15 minutes. So from these four crowned pigeons only 40 *4 = 160 registrations were
made.
The observations were recorded by using a Psion Organiser II, type LZ 64. With the use of
the computerprogramme “The Observer” (Noldus Information Technology, 1995) a
configurationfile was written. For this use an ethogram was set up.
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