White-bellied Sea Eagle Haliaeetus Leucogaster Research Articles

King cobra Ophiophagus hannah exhibiting breaching behaviour while swimming in response to a predation threat from a white-bellied sea eagle Haliaeetus leucogaster

King cobra Ophiophagus hannah exhibiting breaching behaviour while swimming in response to a predation threat from a white-bellied sea eagle Haliaeetus leucogaster

Metal and Isotope Analysis of Bird Feathers in a Contaminated Estuary Reveals Bioaccumulation, Biomagnification, and Potential Toxic Effects.

The Derwent estuary, in south east Tasmania, is highly contaminated with heavy metals, mainly due to past industrial pollution. This study sought to determine the extent of contamination, bioaccumulation, and biomagnification in the resident bird community and therefore to infer the potential for adverse effects in birds. Thirteen metals were measured from breast feathers (n = 51 individuals) of eight sympatric species of aquatic bird. Stable carbon (δ13C) and nitrogen (δ15N) isotopes were used to identify dietary sources of contaminants, trophic level, and potential biomagnification through food chains. Generalised linear models revealed that metal burdens were often poorly correlated with δ 13C, indicating their uptake from a range of freshwater, brackish, and marine carbon sources-not surprising due to widespread contamination across the tidal estuary. Feather mercury increased significantly with trophic level (inferred from δ15N). White-bellied Sea-eagle Haliaeetus leucogaster samples contained 240 times more mercury than feral Goose Anser cygnoides. Feather arsenic and copper concentrations were significantly higher in birds feeding lower in the food chain. For several piscivorous species, both chick and adults were sampled revealing significantly higher feather mercury, zinc, and selenium in adults. Feathers from birds found dead along the banks of the estuary had significantly higher lead loads than from live birds, and numerous individuals had levels of mercury, zinc, and lead above toxic thresholds reported in other studies. These results highlight the need to include biota from higher trophic levels in contaminant monitoring programs to understand fully the fate and broader implications of contaminants in the environment.

Pulau Ling: an important seabird hotspot on the east coast of Peninsular Malaysia

Pulau Ling is a small rocky island located to the south of Pulau Redang, forming with other southeast small islands, the Redang Archipelago, in the state of Terengganu, Malaysia. The island was highlighted in the early 1950s as an important seabird site, although little was then known on the status of seabirds on the island. Field visits were made between May 2015 and September 2015 to assess the importance of this small island to seabird species. Four tern species were identified: two of them, black-naped tern Sterna sumatrana and bridled tern Onychoprion anaethetus, were found to breed there, while the other two species, great crested tern Thalasseus bergii and roseate tern Sterna dougallii were found to use the island as a stopover site without any evidence of breeding. Furthermore, the Pacific Eastern Reef egret Egretta sacra (the black morph), was also found to breed on the island. Other species encountered included white-bellied sea eagle Haliaeetus leucogaster (recorded once in June 2015, soaring over the island). These preliminary data show the importance of such small rocky outcrops for tropical breeding and migrating seabirds, where food availability and lack of disturbance may be the two main drivers for diversity and survival.

Breeding landscape and nest spacing of two coastal raptors (Accipitriformes: White-bellied Sea Eagle Haliaeetus leucogaster and Brahminy Kite Haliastur indus) in Peninsular Malaysia

The White-bellied Sea Eagle Haliaeetus leucogaster (Gmelin JF, 1788) and Brahminy Kite Haliastur indus (Boddaert, 1783) are two resident coastal raptors from India through Australia. Data on the breeding landscape and nest spacing of these raptors in Southeast Asia are limited. In this study, field observations were conducted bimonthly from February 2012 to July 2013 on Penang Island and in Matang Mangrove Forest in Western Peninsular Malaysia. Nine types of landscape and 17 study areas were investigated, and habitat variables were analyzed using ArcGIS software. A total of 88 White-bellied Sea Eagle and 212 Brahminy Kite nests were located. 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). By contrast, area size (ha), elevation (m above sea level), and distance to shore (m) had no significant differences (p > 0.05). The White-bellied Sea Eagle and Brahminy Kite preferred dipterocarp and mangrove forests, respectively. Nest spacing was analyzed for 75 White-bellied Sea Eagle nests (consisting of seven occupied and 68 unoccupied nests) in Penang National Park and 210 Brahminy Kite nests (consisting of 27 occupied and 183 unoccupied nests) in Matang Mangrove Forest. The average distance between the occupied nests of the White-bellied Sea Eagle was 663.6 (± 377.3 standard deviation, SD, n = 7) m, whereas that of the Brahminy Kite was 1489.4 (± 1134.5 SD, n = 27) m. The proportion of nest occupancy to all nests was 9.3% for the White-bellied Sea Eagle and 12.8% for the Brahminy Kite. Conservation of islands covered with dipterocarp and mangrove forests is essential to the survival of coastal raptors in Southeast Asia.

Morphological observations of the thrombocyte of white-bellied sea eagle Haliaeetus leucogaster

The white-bellied sea eagle, Haliaeetus leucogaster, is a large territorial raptor species associated with coastal regions, lakes and river systems. It has an extensive distribution from the western coast of India throughout the Indo-Malaysian region, Papua New Guinea and Australia. Blood samples of the white-bellied sea eagle housed at Nakhonratchasima Zoo, Nakhon Ratchasima province in northeastern Thailand, were collected. Morphological observations of the thrombocytes were examined using scanning electron and transmission electron microscopy. The results revealed the following information: thrombocytes of white-bellied sea eagle were oval to rod-shaped with a rough membrane and the presence of a spread monolayer. Within the cytoplasm of the white-bellied sea eagle, thrombocytes were vesicles of varying sizes. During blood clot formation, the thrombocytes spread their membrane and used pseudopodials to attach to red blood cells causing blood cell clumping to occur. This study indicates that the morphology and activity of the white-bellied sea eagle thrombocytes differs from other non-mammalian thrombocytes.

Conservation status of the White-Bellied Sea-Eagle Haliaeetus leucogaster in Australia determined using mtDNA control region sequence data

Considered to have a declining world population, concern has been expressed in recent years over the conservation status of the White-bellied Sea-Eagle Haliaeetus leucogaster (Gmelin, 1788) within Australia. We used mitochondrial (mtDNA) control region sequence data to investigate the current distribution of genetic variation in this species at the continental level and within and between specified regional units. We were specifically interested in identifying breaks in genetic connectivity between the west and east of the continent and between Tasmania and the Australian mainland. We also investigated the likelihood of a bottleneck at the time of colonisation, and propose hypotheses regarding colonisation history. Sequence data were obtained from 128 individuals describing 15 haplotypes. Overall, diversity was low and AMOVA results failed to provide any significant level of genetic subdivision between regions. We suggest that the population expanded from a bottleneck approximately 160,000 years ago during the late Pleistocene, and spread throughout the continent through a contiguous range expansion. There is insufficient evidence to suggest division of the population into different units for conservation management purposes based on the theoretical definition of the ‘evolutionary significant unit’. It is clear from the analysis that there are signatures of both historical and contemporary processes affecting the current distribution. Additional sampling and confirmation of the perceived pattern of population structure using a nuclear marker is recommended to validate conservation monitoring and management at a continental scale.

Pesticide-related Eggshell Thinning in Australian Raptors

Eggshell thickness of 32 species of Australian raptors, relative to DDT use, was investigated. Nine species showed a significant reduction in shell thickness since DDT was introduced to agriculture in 1946: Whistling Kite Haliasfur sphenurus; Brahminy Kite Haliastur indus; White-bellied Sea-Eagle Haliaeetus leucogaster; Marsh Harrier Circus aerugrnosus; Collared Sparrowhawk Accipiter cirrhocephalus; Peregrine Falcon Falco peregrlnus; Grey Falcon Falco hypoleucos: Australian Hobby Falco longipennis; and Southern Boobook Ninox novaeseelandiae. Average reductions in thickness ranged from 2% (Collared Sparrowhawk and Australian Hobby) to 10% (Peregrine Falcon). These levels are unlikely to be causing widespread population declines. However, several clutches from these species were so thin (maximum thinning ranged from 15% for the Grey Falcon to 45% for the Whistling Kite) that they were likely to break during incubation. Thus, localised breakage of eggs and reproductive failure has probably occurred. In general, bird-eating raptors and those living in areas of intensive agriculture were worst affected. Ostensibly, DDT consumption declined from a peak in 1973 to none in 1989. Reduction in shell-thickness occurred as early as 1947 and was greatest throughout the 1970s and 1980s. The uncontaminated eggs of owls were thinner than those of other raptors, perhaps partly reflecting the owls' lower absorption of dietary calcium (bone).

Absence of a Pelagic Phase in the Life Cycle of the Flatback Turtle, Natator depressa (Garman)

Prey remnants at island feeding stations of the white-bellied sea-eagle Haliaeetus leucogaster (Gmelin) were examined along the Great Barrier Reef. Juvenile flatback turtles Natator depressa (Garman) 14-24cm in shell length were preyed upon primarily within the main feeding and nesting range of adult turtles. There was no evidence of predation on the juveniles of other species of sea-turtles which are reported to inhabit oceanic environ-