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Predictive habitat modelling to estimate petrel breeding colony sizes: sooty shearwaters (Puffinus griseus) and mottled petrels (Pterodroma inexpectata) on Whenua Hou Island
Citation
Scott, D and Moller, H and Fletcher, D and Newman, J and Aryal, J and Bragg, C and Charleton, K, Predictive habitat modelling to estimate petrel breeding colony sizes: sooty shearwaters (Puffinus griseus) and mottled petrels (Pterodroma inexpectata) on Whenua Hou Island, New Zealand Journal of Zoology, 36, (3) pp. 291-306. ISSN 0301-4223 (2009) [Refereed Article]
Copyright Statement
Copyright 2009 The Royal Society of New Zealand
DOI: doi:10.1080/03014220909510156
Abstract
Between 2001 and 2006, we systematically
sampled the entire coast of Whenua Hou,
a rugged offshore island in southern New Zealand,
to estimate the population densities of sooty
shearwaters (Puffinus griseus) and mottled petrels
(Pterodroma inexpectata) by counting the entrances
of breeding burrows. A two-step regression
modelling process using binomial errors was used
to predict the presence of a colony, and a normal
general linear model was used to predict the density
of entrances within colonies. Aerial photography,
GI S and a Digital Elevation Model were used to
extract relevant habitat and location variables, and
a combination of both regression models was used
to predict the density of breeding burrows within
each 5.32 m2 pixel on the island. This complex GIS
and habitat prediction modelling approach gave
population estimates very similar to a more traditional
simple area extrapolation method and gave
no improvement in precision. However, correction
for the slope of the land increased our simple area
estimates of population size by 11%. We estimate
populations of sooty shearwater and mottled petrel
breeding pairs at 173 000 (162 000–190 000) and
160 000 (123 000–197 000) respectively. Based
on this number of breeding pairs, we calculate that
Whenua Hou supports a total population of 868 000
(554 000–1 270 000) sooty shearwaters. Our estimate
of the total mottled petrel population 202 000
pairs (162 000–242 000) is comparable with the only
published estimate, but could be an underestimate
because mottled petrels are sometimes found in large
burrows. More research for robust estimation of
population trends is needed to assess the conservation
status of mottled petrels.
Item Details
Item Type: | Refereed Article |
---|---|
Research Division: | Environmental Sciences |
Research Group: | Environmental management |
Research Field: | Wildlife and habitat management |
Objective Division: | Environmental Management |
Objective Group: | Other environmental management |
Objective Field: | Other environmental management not elsewhere classified |
UTAS Author: | Aryal, J (Dr Jagannath Aryal) |
ID Code: | 80433 |
Year Published: | 2009 |
Web of Science® Times Cited: | 33 |
Deposited By: | Geography and Environmental Studies |
Deposited On: | 2012-10-31 |
Last Modified: | 2013-06-11 |
Downloads: | 1 View Download Statistics |
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