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