Interspezifisches Verhalten zwischen Rotkappenfruchttauben (Ptilinopus pulchellus) und anderen tropischen Kleinvögeln in Gemeinschaftshaltung: Wie stark sind die Einflüsse auf trophischer, räumlicher und reproduktiver Ebene?

Interspecific behaviour between Beautiful Fruit-doves (Ptilinopus pulchellus) and other softbills in mixed aviaries: How severe are the impacts on the trophic, spatial and reproductive level? 

Bachelorarbeit

94 Seiten.

Zoologisches Institut Universität zu Köln.
Betreuung: T. Ziegler, B. Marcordes
Kölner Zoo

Abstract:

Ex-situ breeding programmes that are aimed at augmenting natural populations are important means to conserve species. Therefore, studies that give some indication of the animals’ behaviour may lay the foundation for possible future breed-and-release programmes that can only be properly applied to species whose ecological and behavioural requirements are sufficiently known, i.e. for which husbandry practices are well established.
This study focuses on the impact of other softbills on the trophic, spatial and reproductive behaviour of Beautiful Fruit-doves (Ptilinopus pulchellus). Based on the relatively low ex-situ breeding success of this species it is assumed that there is a relation between the behavior of P. pulchellus and the presence of other birds – particularly other dove species – within the same aviary. For the purpose of this investigation data were collected on three adult couples and a single adult female of Beautiful Fruit-doves under four different husbandry conditions at Cologne Zoo.
The results of this study support the assumption of behavioural differences among differently housed individuals, although not all presuppositions could be accepted without reservation. Thus, the observed differences in behaviour patterns were not strictly due to the presence of other birds within the respective aviary. Regarding the trophic level, the assumption of a lower energetic requirement in separately kept P. pulchellus was validated, whereas the supposition of differences in frequencies and duration of ingestion periods among individuals was refuted. In addition, an analysis of the spatial level confirmed a rather distinct spatial distance between co-housed species. On the contrary, the investigation of general, sociopositive and attentive behaviour patterns only revealed significant differences regarding the birds’ locomotive behaviour. Against all expectations, the separately kept Beautiful Fruitdoves did not display the highest frequencies of locomotive behaviour, but merely the longest durations of movements. However, the respective manners of movement clearly indicated different behaviour patterns among focal animals. Whereas co-housed individuals were rather covering short distances, separately kept birds used the whole enclosure while moving, on average, for longer periods. Lastly, the investigation of the reproductive level revealed no clear proof of the impact of other species on the breeding success of P. pulchellus which might have been due to the short observation period.

In conclusion, the impacts of other softbills on the behaviour of Beautiful Fruit-doves might be less severe as previously assumed, although long-term studies are indispensable to verify these findings. However, information available for this species is still extremely sketchy. Thus, the here obtained results provide a good basis for the development of new strategies to improve the husbandry conditions of Ptilinopus pulchellus and possibly other related species for which conservation actions are needed.

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