EEP Crowned pigeon number 4

EEP STUDBOOK CROWNED PIGEONS
6.5 Information on crowned pigeons in Papua New Guinea
6.5.1 Ecology of crowned pigeons
Crowned pigeons occur in the swampy lowland forests of New Guinea until a height of
maximal 500 meters above sea level (Wetzel, 1992a). Because New Guinea is very
mountainous, with mountains up to 4,500 meters in the heart of the island, crowned pigeons
can only be found along the coasts of New Guinea. They are real ground-dwellers, because it
is very energy consuming to fly for a bird of this size. They are turkey-sized and in good
condition crowned pigeons weigh about 2 - 2.5 kilograms (Weekers, 1991), although Grzimek
(1974) states that their weight is about 1.3 kilograms, which is definitely false for a mature
crowned pigeon. They only fly if necessary: to sleep, to fly and to produce offspring. When
they fly they make a very clumsy impression and they have to take great pains to land safely
and not to drop off the branch (Rand and Gilliard, 1967). Although no research has been done
to the use of space in the wild, they do not seem to be territorial. They are said to live in
groups during the year, and in the breeding season they look for a suitable place to brood, not
in the neighbourhood of another nest. It is not likely that they will allow any other crowned
pigeon in the neighbourhood of the nest, but no research has been done into this subject.
Social behaviour
Although most zoos keep their crowned pigeons in pairs, in the wild they are often found in
groups up to about ten individuals (Rand and Gilliard, 1967; Goodwin, 1983; Coates, 1985),
but also groups of ten up to thirty individuals have been found (Coates, 1985). Probably in
this way young crowned pigeons can choose their own partner (Nijboer, pers. comm.).
Research has been done on the time-budgets of crowned pigeons in captivity and it became
clear that crowned pigeons, as well in a small as in a big enclosure, have an almost mixed
daily rhythm, which is displayed every day (Stockwell, 1996).
In aggressive as well as defensive threat display, one or both wings are raised and the tail is
jerked up and down. This movements appear to be the equivalent of the similar and probably
homologous tail movements of the green pigeons Treron and the wing twitching in agnostic
and sexual situations of other pigeons (Goodwin, 1983).
Feeding
In their feeding behaviour they do not differ significantly from other forest dwelling and
largely ground living pigeons (Goodwin, 1983). Crowned pigeons feed on fruits (mainly figs)
and seeds of the ground, by foraging. Also in zoos it could be observed that crowned pigeons
spend a lot of time foraging. Their relatively long bill is very useful for this purpose. They do
not scratch for feed with their feet but only shift the substrate, if it is loose and friable, with a
sideways flicking movement of the bill (Goodwin, 1983). Furthermore they are said to feed
on small insects, and one reference even reports that scheepmaker's crowned pigeons should
eat small crabs (Grant in Coates, 1985), but this has never been confirmed.
Almost nothing is known about the composition of the diet of crowned pigeons, neither in the
wild nor in captivity (Hallebeek and Nijboer, 1996).
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