Pied Currawongs and the decline of native birds
Karen L. Bayly and Daniel T. Blumstein
Emu 101(3) 199 - 204
Abstract
Predation pressure by Pied Currawongs,
Strepera graculina, has been implicated as a principal
factor in the decline of native bush bird populations. We review the available
literature, analyse the types of avian species reported as being preyed on by
currawongs, and examine whether this evidence suggests that increased
currawong predation is limiting bird populations. Virtually all species
reported as prey could be classified as ‘introduced/common’
and ‘native/common’. The results suggest that predation is
greatest on introduced/common species, and less than expected on
native/common species and native/rare species. Currawongs seem to be
generalist predators and do not appear to target any particular size or age
range of avian prey. Nonetheless, it is not clear that currawongs are
primarily responsible for predation on both nests and adults in all
populations of small native birds, nor are the possible compensatory effects
of density-dependent population growth rates in small Australian passerines
well understood. It is also difficult to separate the effects of predation
(increased mortality, possible reduced recruitment) from the effects of gross
habitat change (degradation, fragmentation, changes in species composition
and/or abundance). We discuss the limitations of some previous studies on
currawong predation, and suggest possible directions for future research.
Full text doi:10.1071/MU00018
© CSIRO 2001





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