Population density, home range, and habitat use of crested serpent-eagles (Spilornis cheela hoya) in Southern Taiwan

Using distance-based analysis and compositional analysis at different spatial scales

Bruno A. Walther, Ta Ching Chou, Pei Fen Lee

Research output: Contribution to journalArticle

Abstract

For many tropical raptors, studies of population density and habitat use are still lacking. We used radio-tracking to study population density, home-range size, and habitat use of the Formosan Crested Serpent-Eagle (Spilornis cheela hoya) in Kenting National Park, southern Taiwan, during 1995-1997 and 1998-2007. Over two years, we documented a minimum population density of 2.69 individuals/km2, which is one of the highest ever reported. Home ranges calculated using minimum convex polygons and 95% fixed kernel areas averaged 12.34 km2 and 2.86 km2 (n = 18), respectively. Core areas represented by the 50% fixed kernel areas averaged 0.41 km2. We used distance-based analysis and compositional analysis to compare habitat use within the entire study area and the home ranges. Both methods indicated the overwhelming use (>90%) of somewhat degraded and semi-open mixed forests, followed by the use of Acacia confusa forests and grasslands to a much lesser degree. Habitat use was nonrandom both within the study area and the home range, as mixed forests covered only 24.4% of the study area. Many perch sites were near the primary monsoon forest, which was, however, almost never used for hunting. As many other species of serpent-eagles are threatened by habitat loss and human persecution, our study provides valuable information for their future monitoring and management.

Original languageEnglish
Pages (from-to)195-209
Number of pages15
JournalJournal of Raptor Research
Volume48
Issue number3
DOIs
Publication statusPublished - 2014

Fingerprint

Hoya
eagles
Taiwan
population density
mixed forests
habitats
Acacia confusa
perch
birds of prey
seeds
habitat destruction
radio
national parks
grasslands
home range
monitoring

Keywords

  • core area
  • Crested Serpent-Eagle
  • habitat preference
  • habitat selection
  • home range
  • Spilornis cheela hoya
  • Taiwan

ASJC Scopus subject areas

  • Animal Science and Zoology

Cite this

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title = "Population density, home range, and habitat use of crested serpent-eagles (Spilornis cheela hoya) in Southern Taiwan: Using distance-based analysis and compositional analysis at different spatial scales",
abstract = "For many tropical raptors, studies of population density and habitat use are still lacking. We used radio-tracking to study population density, home-range size, and habitat use of the Formosan Crested Serpent-Eagle (Spilornis cheela hoya) in Kenting National Park, southern Taiwan, during 1995-1997 and 1998-2007. Over two years, we documented a minimum population density of 2.69 individuals/km2, which is one of the highest ever reported. Home ranges calculated using minimum convex polygons and 95{\%} fixed kernel areas averaged 12.34 km2 and 2.86 km2 (n = 18), respectively. Core areas represented by the 50{\%} fixed kernel areas averaged 0.41 km2. We used distance-based analysis and compositional analysis to compare habitat use within the entire study area and the home ranges. Both methods indicated the overwhelming use (>90{\%}) of somewhat degraded and semi-open mixed forests, followed by the use of Acacia confusa forests and grasslands to a much lesser degree. Habitat use was nonrandom both within the study area and the home range, as mixed forests covered only 24.4{\%} of the study area. Many perch sites were near the primary monsoon forest, which was, however, almost never used for hunting. As many other species of serpent-eagles are threatened by habitat loss and human persecution, our study provides valuable information for their future monitoring and management.",
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T2 - Using distance-based analysis and compositional analysis at different spatial scales

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AU - Chou, Ta Ching

AU - Lee, Pei Fen

PY - 2014

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N2 - For many tropical raptors, studies of population density and habitat use are still lacking. We used radio-tracking to study population density, home-range size, and habitat use of the Formosan Crested Serpent-Eagle (Spilornis cheela hoya) in Kenting National Park, southern Taiwan, during 1995-1997 and 1998-2007. Over two years, we documented a minimum population density of 2.69 individuals/km2, which is one of the highest ever reported. Home ranges calculated using minimum convex polygons and 95% fixed kernel areas averaged 12.34 km2 and 2.86 km2 (n = 18), respectively. Core areas represented by the 50% fixed kernel areas averaged 0.41 km2. We used distance-based analysis and compositional analysis to compare habitat use within the entire study area and the home ranges. Both methods indicated the overwhelming use (>90%) of somewhat degraded and semi-open mixed forests, followed by the use of Acacia confusa forests and grasslands to a much lesser degree. Habitat use was nonrandom both within the study area and the home range, as mixed forests covered only 24.4% of the study area. Many perch sites were near the primary monsoon forest, which was, however, almost never used for hunting. As many other species of serpent-eagles are threatened by habitat loss and human persecution, our study provides valuable information for their future monitoring and management.

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