Is the conservation value of small urban remnants of eucalypt forest limited by increased levels of nest predation?
Scott D. Piper A B and Carla P. Catterall A
A Faculty of Environmental Sciences, Griffith University, Nathan, Qld 4111, Australia.
B Corresponding author. Email: firstname.lastname@example.org
Emu 106(2) 119-125 http://dx.doi.org/10.1071/MU05043
Submitted: 5 September 2005 Accepted: 28 February 2006 Published: 19 May 2006
Levels of predation on bird nests may be increased in small remnant patches compared with levels in extensive forests, owing to edge-related nest predation or mesopredator release. Previous work using artificial nests has demonstrated that increased rates of nest predation, owing mainly to avian predators, occur near edges of fragmented subtropical Australian eucalypt forests. This implies that levels of nest predation within small patches of remnant forest, which could effectively be all ‘edge’, may also be increased. We used artificial nests, deployed on the ground and 1–4 m above the ground in shrubs, to compare levels of nest predation and predator assemblages between interiors of small (10–20 ha) suburban remnant patches and extensive tracts (>400 ha) of subtropical Australian eucalypt forest. Most predation of nests in shrubs in both remnants and extensive forests was by birds, although there were some differences in the assemblages involved. Ground-nests were far more likely to be depredated by mammals or lizards in the remnants than in the extensive forests. However, despite the differences between their predator assemblages, overall levels of nest predation did not differ significantly between remnants and extensive forests, suggesting that any edge-related predation was of insufficient spatial extent to affect the interiors (>50 m from external edges) of remnants in this size-class. Eucalypt forest remnants of 10–20 ha often support bird assemblages typical of extensive forest tracts, but may act as population sinks for these species if levels of nest predation are excessive. Our results support the contention, however, that remnants in this size-class are useful to the conservation of forest bird assemblages.
Andrén H. (1995). Effects of landscape composition on predation rates at habitat edges. In ‘Mosaic Landscapes and Ecological Processes’. (Eds L. Hansson, L. Fahrig and G. Merriam.) pp. 225–255. (Chapman and Hall: London.)
Conservation of woodland birds in a fragmented rural landscape.
Pacific Conservation Biology
Evidence of an edge effect on avian nest success.
Habitat loss and population decline: a meta-analysis of the patch size effect.
Predation rates of artificial nests in the edge and interior of a southern Victorian forest.
Catterall C. P., Green R. J., and Jones D. N. (1991). Habitat use by birds across a forest-suburb interface in Brisbane: implications for corridors. In ‘Nature Conservation 2: The Role of Corridors’. (Eds D. A. Saunders and R. J. Hobbs.) pp. 247–258. (Surrey Beatty: Sydney.)
Use of remnant forest habitat by birds during winter in subtropical Australia: patterns and processes.
Pacific Conservation Biology
Deforestation, urbanisation and seasonality: interacting effects on a regional bird assemblage.
Mesopredator release and avifaunal extinctions in a fragmented system.
Quail eggs, modelling clay eggs, imprints and small mammals in an Australian woodland.
Experimental evidence for edge-related predation in a fragmented agricultural landscape.
Australian Journal of Ecology
Graetz R.D., Wilson M.A., and Campbell S.K. (1995). Landcover disturbance over the Australian continent. Australian Department of Environment, Sport and Territories, Biodiversity Series Paper No. 7, Canberra.
Nest predation and neotropical migrant songbirds: piecing together the fragments.
Wildlife Society Bulletin
Do edge effects occur over large spatial scales?
Trends in Ecology & Evolution
Predicting the impacts of edge effects in fragmented habitats.
Low T. (1995). ‘The Animals of Brisbane: A Vertebrate Status Review.’ (Brisbane City Council: Brisbane.)
Loyn R. H. (1987). Effects of patch area and habitat on bird abundances, species numbers and tree health in fragmented Victorian forests. In ‘Nature Conservation: The Role of Remnants of Native Vegetation’. (Eds D. A. Saunders, G. W. Arnold, A. A. Burbidge and A. J. M. Hopkins.) pp. 65–77. (Surrey Beatty: Sydney.)
Forecasting the impacts of habitat fragmentation. Evaluation of species-specific predictions of the impact of habitat fragmentation on birds in the box-ironbark forests of central Victoria, Australia.
Differences in depredation by small predators limit the use of plasticine and zebra finch eggs in artificial-nest studies.
The contribution of artificial nest experiments to understanding avian reproductive success: a review of methods and conclusions.
Marzluff J. M., and Restani M. (1999). The effects of forest fragmentation on avian nest predation. In ‘Forest Fragmentation: Wildlife and Management Implications’. (Eds J. A. Rochelle, L. A. Lehmann and J. Wisniewski.) pp. 155–169. (Brill Academic Publishing: Köln, Germany.)
The influence of fragment size and edge on nest predation in urban bushland.
Edge effects in fragmented forests: implications for conservation.
Trends in Ecology & Evoloution
P. W. C.
The effect of edge on avian nest success: how strong is the evidence?
A particular case and a general pattern: hyperaggressive behaviour by one species may mediate avifaunal declines in fragmented Australian forests.
Effects of edge type and nest height on predation of artificial nests within subtropical Australian eucalypt forests.
Forest Ecology and Management
Impacts of picnic areas on bird assemblages and nest predation activity within Australian eucalypt forests.
Landscape and Urban Planning
Does adjacent land use affect predation of artificial shrub-nests near eucalypt forest edges?
Sources, sinks, and population regulation.
Quinn G. P., and Keogh M. J. (2002). ‘Experimental Design and Data Analysis for Biologists.’ (Cambridge University Press: Cambridge, UK.)
Song sparrows, top carnivores and nest predation: a test of the mesopredator release hypothesis.
Nest predation experiments with quail eggs: too much to swallow?
Avian life histories: is extended parental care the southern secret?
Bushland modification and styles of urban development: their effects on birds in south-east Queensland.
Nest predation and differential insular extinction among selected forest birds of central Panama.
Artificial nest predation rates in tropical and temperate forests: a review of the effects of edge and nest site.
Different nest predator faunas and nest predation risk on ground and shrub nests at forest ecotones: an experiment and a review.
Reconstructed dynamics of rapid extinctions of chaparral-requiring birds in urban habitat islands.
SPSS Inc. (2003). ‘SPSS for Windows, Release 12.0.1.’ (SPSS Inc.: Chicago, IL.)
L. N. H.
Predation of artificial nests in a fragmented landscape on the New England Tablelands of New South Wales.
Terborgh J., and Winter B. (1980). Some causes of extinction. In ‘Conservation Biology’. (Eds M. E. Soulé and B. A. Wilcox.) pp. 119–133. (Sinauer: Sunderland, MA.)
Wilcove D. S., McLellan C. H., and Dobson A. P. (1986). Habitat fragmentation in the temperate zone. In ‘Conservation Biology: The Science of Scarcity and Diversity’. (Ed. M. E. Soulé.) pp. 237–256. (Sinauer: Sunderland, MA.)
Nesting success and nest predators in forest fragments: a study using real and artificial nests.