Emu 2014, 114, 97-105
doi:10.1071/MU13003_AC
© BirdLife Australia 2014
Supplementary material
Nest-site use by an introduced parrot in New Zealand
Josie A. GalbraithA,C, Mick N. CloutA and Mark E. HauberB
A
School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand.
B
Department of Psychology, Hunter College and the Graduate Center of the City University of New
York, 695 Park Avenue, New York, NY 10065, USA.
C
Corresponding author. Email: [email protected]
Page 1 of 5
Emu 2014
doi:10.1071/MU13003_AC
Table S1.
© BirdLife Australia 2014
Variables characterising the microhabitat, macrohabitat and landscape-scale habitat used in the analysis of nest-site selection of Eastern
Rosellas in the Auckland region over the 2008–9 and 2009–10 breeding seasons
DBH, diameter at breast height
Variable
Microhabitat scale
Dimensions of entrance (cm)
Area of entrance (cm2)
Shape
Depth of cavity (cm)
Diameter at nest entrance (cm)
Height of nest entrance (m)
Orientation of entrance (°)
Angle of entrance (°)
Position of cavity
Entrance vegetation
Tree species
Height of tree (m)
DBH of tree (cm)
Climber score
Description
Height (length of longest axis) and width (widest point perpendicular to height) of the entrance hole
Cross-sectional area of the entrance hole (height × width), after Elliott et al. (1996)
Rough shape of the entrance hole – circular, elliptical or slit
Internal distance from lower edge of entrance hole to floor of cavity
Diameter of trunk or branch at the entrance hole
Vertical height from entrance hole to ground
Compass orientation of entrance hole: 0–360° (left blank if angle of entrance = 0 or 180°)
Plane of the cavity entrance, ranging from 0 to 180°, where 0°, open to the sky; 90°, perpendicular to the ground; 180°, facing the ground
(adapted from Heinsohn et al. 2003)
Trunk, branch or spout (broken-off end of branch or trunk)
1, no vegetation (foliage or other branches) close to entrance (<1 m); 2, very little vegetation close to entrance; 3, some vegetation close
to entrance; 4, vegetation in contact with or surrounding entrance
Diameter of nest tree at breast height (~1.2 m off the ground)
1, nest plant with no climbers; 2, small numbers of climbers attached (1 or 2 strands); 3, large numbers of climbers attached (>2 strands or
large aerial roots)
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Emu 2014
doi:10.1071/MU13003_AC
Variable
Macrohabitat scale
Canopy height (m)
Canopy closure (%)
Ground cover (%)
Richness
Tree density (stems ha–1)
Basal area (m2 ha–1)
Potential nests (nest trees per plot)
Landscape scale
Topographic unit
Elevation (m above sea level)
Edge (m)
Water (m)
© BirdLife Australia 2014
Description
Table S1.
(Cont.)
Height of the canopy in the centre of the plot
Proportion of the sky obscured by canopy vegetation, estimated visually from the centre of the plot
Percentage of the plot covered by grasses, creepers or shrubs <2 m tall
Number of tree species >5-cm DBH recorded within the circular plot
Number of trees >5-cm DBH recorded within the circular plot, multiplied to give a value per hectare
Basal area of all trees >5-cm DBH within the circular plot, summed and multiplied to give a value per hectare
Number of trees bearing cavities potentially available for nesting within the circular plot
1, Ridge; 2, Upper slope; 3, Mid-slope; 4, Lower slope; 5, Gully–Lowland
Height above sea level
Distance from nesting site to nearest edge of forest
Distance from nesting site to nearest stream, lake or other freshwater body
Page 3 of 5
Emu 2014
doi:10.1071/MU13003_AC
Table S2.
© BirdLife Australia 2014
List of a priori models used in logistic regression analyses comparing plots with Eastern Rosella nesting sites and randomly selected available
sites without nests
Models were based on factors identified in previous studies that may influence nest-site selection, including vegetation structure and access to resources
Structure and density of
vegetation
Canopy Height
Canopy Closure
Ground Cover
Richness
Tree Density
Basal Area
Canopy Height + Canopy Closure
Canopy Closure + Ground Cover
Tree Density + Basal Area
Canopy Height + Canopy Closure + Tree Density
Canopy Height + Canopy Closure + Tree Density + Basal Area
Access to resources
Edge
Water
Potential Nests
Edge + Water
Potential Nests + Edge
Potential Nests + Water
Potential Nests + Water + Edge
Landscape location
Topographic Unit
Elevation
Elevation + Topographic Unit
Other models
Potential Nests + Basal Area
Potential Nests + Elevation
Full model (all variables)
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Emu 2014
doi:10.1071/MU13003_AC
© BirdLife Australia 2014
References
Elliott, G. P., Dilks, P. J., and O’Donnell, C. F. J. (1996). Nest site selection by Mohua and Yellow-crowned
Parakeets in beech forest in Fiordland, New Zealand. New Zealand Journal of Zoology 23, 267–278.
doi:10.1080/03014223.1996.9518085
Heinsohn, R., Murphy, S., and Legge, S. (2003). Overlap and competition for nest holes among Eclectus Parrots,
Palm Cockatoos and Sulphur-crested Cockatoos. Australian Journal of Zoology 51, 81–94.
doi:10.1071/ZO02003
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