Nest-Site Selection, Habitat Suitability And Behavioural Ecology Of The White-Bellied Sea Eagle Haliaeetus Leucogaster And Brahminy Kite Haliastur Indus In Nothern Peninsular Malaysia
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Date
2014-06
Authors
Khaleghizadehrostami, Abolghasem
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
The White-bellied Sea Eagle Haliaeetus leucogaster and Brahminy Kite Haliastur
indus are two resident species of coastal raptors. Field observations were conducted
twice per month from February 2012 to September 2013 on Penang Island and in
Matang Mangrove Forest in western coast of Peninsular Malaysia. A total of 88 Whitebellied
Sea Eagle and 212 Brahminy Kite nests were located in nine types of landscape
and 17 study areas. Data were analysed using ArcGIS, SPSS and R statistical software.
Logistic regression analysis showed that the proportion (%) of forest land and urban
areas was significantly different between study areas with and without nests (p<0.05).
The White-bellied Sea Eagle and Brahminy Kite preferred dipterocarp and mangrove
forests, respectively. The average distance between occupied nests of the White-bellied
Sea Eagle and Brahminy Kite was 663.6 and 1,489.4 m, respectively. The proportion of
occupied nests was 9.3% in the White-bellied Sea Eagle and 12.8% in the Brahminy
Kite. Logistic Regression analysis between selected nest trees of White-bellied Sea
Eagle and random trees showed that among the variables of the nesting area, only the
location of the nest tree in the middle of a slope was a significant factor in the model,
and among the variables of the nest trees, only the nearest distance between nest trees
had a significant effect on the selection of nest trees compared with randomly selected
trees. Among all the variables considered in relation to nest occupancy in the Brahminy
Kite (including extent of agriculture, productive forest, restricted production forest,
protected forest, unproductive forest, young forests and clear-cut areas, proximity to an
estuary, and distance to villages and main roads), the extent of clear-cut areas was the
only significant determinant of nest occupancy. As the clear-cut area around a nest
increased from zero to just a few hectares, the probability of nest occupancy was steeply
reduced. This effect was particularly evident when clear-cut areas occurred in the
immediate surroundings of a nest (i.e. within 150m). About behaviour, there were
significant differences between species and locations in the percentage of time that the
birds spent for all behaviours; perching, flying, hunting, social behaviour and
competition (p<0.05). Multiple Regression analysis showed that among the
environmental variables, a significant effect was found for the variable of time of day
and weather conditions (p<0.05). Conservation of islands covered with dipterocarp and
mangrove forests is essential to the survival of the coastal raptors in Malaysia.
Description
Keywords
Nest-site selection , habitat suitability and behavioural ecology