scholarly journals Population sizes and the conservation status of endemic and restricted-range bird species on Karakelang, Talaud Islands, Indonesia

2003 ◽  
Vol 13 (1) ◽  
pp. 59-74 ◽  
Author(s):  
Jon Riley

Karakelang, largest of the Talaud Islands, Indonesia, was visited in 1999 with the aim of producing population estimates of globally threatened and Restricted-range bird species. Density estimates were calculated from primary forest and secondary habitats using the variable circular plot method. Eight of the nine restricted-range or threatened species resident on Karakelang were recorded and density estimates calculated for five of these. Two species of rail are endemic to Karakelang, Talaud Bush-hen Amaurornis magnirostris and Talaud Rail Gymnocrex talaudensis. The bush-hen was encountered in secondary habitat but occurred at higher densities in primary forest and the estimated population was 2,350–9,560 birds. The less vocal, cryptic G. talaudensis was noted just twice, in primary forest close to rivers. Both have small populations, are threatened by habitat degradation, hunting, and possibly predation by introduced rats and should be classified as threatened. Population densities of the Endangered, endemic Red-and-blue Lory Eos histrio had remained stable since the last survey in 1997. They occurred at higher densities in primary forest, but were also common in human-made habitats. The estimated population was 8,230–21,400 birds, threatened by habitat loss and trapping for the wild bird trade. Although more commonly encountered in forest, the Near Threatened Blue-naped Parrot Tanygnathus lucionensis was found at higher densities in secondary habitats, and the population was estimated at 8,130–20,700 birds. The Restricted-range Blue-tailed Imperial Pigeon D. concinna was very common on Karakelang (14,500–27,700 birds), whilst the Vulnerable Grey Imperial Pigeon D. pickeringii was recorded rarely; both species were more frequently recorded in primary forest. The endemic Talaud Kingfisher Halcyon enigma occurred at low densities (5,290–8,690 birds), in primary forest and adjacent disturbed areas. It is heavily dependent on primary forest and threatened by habitat loss, and should be classified as Vulnerable. Approximately 350 km2 of primary forest on Karakelang is protected, 250 km2 as a wildlife reserve. However, at present, management is absent and forest is threatened by agricultural encroachment, illegal logging, and fire. Given that all endemic and threatened species were encountered more frequently or occurred at higher densities in primary forests, future conservation efforts should target these protected areas. Management of reserves should involve local stakeholders from government and representatives of island communities. Wildlife trade is a major threat to Eos histrio and strict enforcement of the species' protected status should include monitoring of roost sites, patrols of harbours and markets in Talaud, Sulawesi and the Philippines, and the control of Philippine fishing boats involved in the wild bird trade. Further species-specific research and monitoring is also required.

2001 ◽  
Vol 12 (1) ◽  
pp. 53-78 ◽  
Author(s):  
Jon Riley

The island of Sangihe, Indonesia, was visited in 1998–99 with the aim of producing population estimates of the island's endemic and other restricted-range bird species, some of which were poorly known and thought to be at risk of extinction due to habitat change. The study focused on the last remaining patch of primary forest, on Mount Sahendaruman in southern Sangihe, home to three critically endangered endemic species: Cerulean Paradise-flycatcher Eutrichomyias rowleyi, Sangihe Shrike-thrush Colluricincla sanghirensis, and Sangihe White-eye Zosterops nehrkorni. Population densities were estimated from primary forest and secondary habitats across Sangihe to assess species dependency on primary habitat. Twenty of 24 restricted-range, globally threatened or endemic taxa were recorded and density estimates were calculated for 15 of these. The endemic Red-and-blue Lory Eos histrio is extinct on Sangihe as a result of lowland forest loss. Six species (Nicobar Pigeon Caloenas nicobarica, Sulawesi Dwarf Kingfisher Ceyx fallax, Golden Bulbul Ixos affinis, E. rowleyi, C. sanghirensis, and Z. nehrkorni) were either not recorded or have very small populations and are critically endangered on Sangihe; two species of Tanygnathus parrot are also facing local extinction on the island. The major threat to all these species is the destruction of primary forest; larger species are also threatened by hunting. The remaining endemic and restricted-range species (Blue-tailed Imperial Pigeon Ducula concinna, Sangihe Hanging-parrot Loriculus catamene, Sangihe Scops-owl Otus collari, Lilac-cheeked Kingfisher Cittura cyanotis and Elegant Sunbird Aethopyga duyvenbodei) were more widespread and occurred in secondary habitats. I recommend that L. catamene and A. duyvenbodei, currently treated as globally endangered, be reclassified as near-threatened and vulnerable respectively because of their large populations and tolerance of disturbed habitats. Species with wide global ranges that are represented by endemic subspecies have the greatest tolerance for disturbed habitat. The widespread deforestation of Sangihe has had serious consequences for many bird species and today the island supports the most threatened assemblage of single-island endemic species in Indonesia. Species-specific research to determine the status and ecology of E. rowleyi, C. sanghirensis and Z. nehrkorni, and monitoring of the Sahendaruman forest are desperately needed as a basis for future conservation efforts.


Oryx ◽  
2011 ◽  
Vol 45 (2) ◽  
pp. 234-242 ◽  
Author(s):  
N.A.D. Mallari ◽  
N.J. Collar ◽  
D.C. Lee ◽  
P.J.K. McGowan ◽  
R. Wilkinson ◽  
...  

AbstractThere is widespread concern for many understorey and ground-dwelling bird species in the Philippines that appear intolerant of forest alteration. We present density estimates for 18 key bird species in old growth forest, advanced and early secondary growth and active cultivation within the Puerto Princesa Subterranean River National Park in Palawan. Six species were not recorded in cultivation and the abundance of these and several others increased along the successional gradient from cultivation to old growth forest. Eleven species, including five endemics and three of four threatened species, had highest density estimates in old growth forest. However, several species had high density estimates in the heavily disturbed habitats and every habitat type held highest densities of at least one of the bird species. The commonest habitat association across the bird community was a preference for areas containing large trees, indicating the importance of retention of such trees in allowing suitable ground and understorey microhabitats to persist. Old growth forests have the highest conservation value for Palawan’s endemic birds and, while some species thrive in the anthropogenic habitats that occur within the Park, the present extent of cultivation and associated successional stages within its boundaries should not be increased. We caution against extrapolation of the abundance figures from the Park to the whole island but we suggest that population sizes for the threatened species are likely to be much greater than previously thought. We urge authorities to strengthen management within the protected area network in Palawan to ensure survival of key species.


Mammalia ◽  
2016 ◽  
Vol 80 (4) ◽  
Author(s):  
Julia Salvador ◽  
Santiago Espinosa

AbstractOcelots were historically hunted for their skins but habitat loss is now their most serious threat, causing rapid declines in populations throughout their range. Ocelot abundance has been estimated for various locations across the Neotropics, but we still lack this information from some countries, including Ecuador. Knowing whether ocelot abundance is increasing or decreasing is important to assess the conservation status of this species and the conditions of its habitats in the Ecuadorian Amazon and in the region. To determine whether ocelot abundance and its behavior are affected by human-related activities, camera-trap surveys were carried out in two localities of Yasuní National Park (YNP), one that has experienced hunting, oil extraction, and roads (Maxus Road) and one that is largely unaffected by these activities (Lorocachi). During the survey, 35 and 36 individual ocelots were photographed in Maxus Road and Lorocachi, respectively. Population density estimates were similar for both localities, ranging from 0.31 (SE±6) to 0.85 (SE±17) ocelots/km


1995 ◽  
Vol 5 (1) ◽  
pp. 79-115 ◽  
Author(s):  
Michael Køie Poulsen

SummaryFieldwork on the distribution, status and ecology of birds was conducted in the northern Sierra Madre mountain range, Luzon, Philippines, during March–May 1991 and March-May 1992. The findings show the area to be one of the most important for conservation of threatened species of birds in all Asia. The results are here combined with evidence from earlier surveys by other searchers. Fourteen threatened and 18 near-threatened species are now known from the area. This paper reports on all the threatened and near-threatened resident species of the island of Luzon, with special emphasis on their occurrence in the Sierra Madre mountains. In addition, the paper treats species with very limited global distribution that breed in Luzon, and lists species of forest birds endemic to the Philippines that have not previously been reported from the Sierra Madre mountains. Maps show the known sites for 17 species of special concern for conservation. New data on the altitudinal distribution of threatened and near-threatened species suggest that it is essential to protect primary forest at all elevations.


2001 ◽  
Vol 12 (2) ◽  
pp. 123-150 ◽  
Author(s):  
Luciano N. Naka ◽  
Marcos Rodrigues ◽  
Andrei L. Roos ◽  
Marcos A. G. Azevedo

The island of Santa Catarina lies in the Atlantic Forest Domain of southern Brazil, one of the most threatened ecosys tems on the planet. It holds a wide variety of habitats, ranging from sand dune ‘restingas’ to mature rain forest. We report, for the first time, a survey of the bird species and their conservation status for the different habitats present on the island. We recorded 269 bird species of 54 families (25 species were seabirds). More than 50% (140) of the total number of species were residents or probable residents, 20% (58) were visitors and a relatively high number of species (61, 23%) had indeterminate residential status. Nearly 15% (35 species) of the 244 landbird species observed were endemic to the Atlantic Forest. Habitat specificity was recorded for 40% (97 species). We recorded one Endangered (Solitary Tinamou Tinamus solitarius), one Vulnerable (White-necked Hawk Leucopternis lacernulata), and three Near-threatened species (Azure Jay Cyanocorax caeruleus, Azure-shouldered Tanager Thraupis cyanoptera, Black-backed Tanager Tangara peruviana). We also recorded six locally threatened species that we predict will become extinct in the near future. The future for the birds of the island is uncertain, especially for habitat specialists, due to habitat loss for resort developments, and a lack of concern by the government and local people.


2004 ◽  
Vol 14 (4) ◽  
pp. 261-277 ◽  
Author(s):  
HUW LLOYD

Surveys of threatened lowland forest bird species and forest habitats were conducted during a 21-month census of lowland bird communities in Tambopata, Department of Madre de Dios, south-east Peru. A combination of distance sampling census methods and direct counts was used for the census in five sites located along the Rio Madre de Dios and Rio Tambopata. All five sites consisted of different forest types with significantly different habitat components. Three of these sites were classified as primary forest habitats whilst the remaining two were classified as disturbed forests. Population densities were calculated for eight of the threatened species recorded during the census. Density estimates of non-bamboo specialists were higher in primary forest habitats than in disturbed forest habitats. Density estimates of most bamboo specialists were higher in primary Old Floodplain forest with extensive bamboo understorey than in primary Middle/Upper Floodplain forest with smaller, patchy areas of bamboo understorey. Calculation of regional population estimates based on the amount of forest cover from satellite photographs shows that only two of the threatened bird species have substantial populations currently protected by the Parque Nacional Bahuaja-Sonene and Reservada Nacional de Tambopata. Selective logging operations that reduce overall tree biomass and remove a large proportion of palm tree species from primary forest habitats will have an adverse affect on local populations of four of the threatened bird species in the region.


2021 ◽  
Vol 21 (2) ◽  
Author(s):  
Murilo Luiz e Castro Santana ◽  
Fernando Rogério Carvalho ◽  
Fabrício Barreto Teresa

Abstract: Anthropogenic environmental changes are the main cause of species extinction during the Holocene. Species have been exposed to major source of threats, such as habitat loss and fragmentation, pollution, introduced species, and harvesting, many of which are derived from specific anthropogenic activities, such as urbanization, agriculture, and damming (i.e. fine-scale threats). However, the importance of these threats on the species conservation status in a given region depends on the type of impacts they are exposed to and the susceptibility of species to these impacts. In this study, we used a database of threatened Brazilian freshwater fish species to test whether the major source of threats and the specific anthropogenic impacts to species vary across hydrographic regions and taxonomic groups. Our results showed that habitat loss is a ubiquitous major threat jeopardizing the conservation status of the Brazilian fish species. However, different fine-scale threats mediate this process across hydrographic regions and taxonomic groups. The combination of impacts from agriculture, deforestation, and urbanization affects most of the threatened species in the basins of the Northeast, South, and Southeast, including the species of the most threatened order, the Cyprinodontiformes. Damming is the main human activity affecting threatened species of Siluriformes, Characiformes, Gymnotiformes, and Cichliformes, especially in northern basins (Amazon and Tocantins-Araguaia). Therefore, we found that specific fine-scale threats influencing threatened species vary across hydrographic regions and taxonomic groups, probably due to geographic variability in the incidence of human activities and differential niche requirements and vulnerability of species to these activities.


Oryx ◽  
2007 ◽  
Vol 41 (1) ◽  
pp. 101-105 ◽  
Author(s):  
Luis Rivera ◽  
Natalia Politi ◽  
Enrique H. Bucher

The Tucumán parrot Amazona tucumana is a rare, Near Threatened species on CITES Appendix I with a restricted range in the tropical and subtropical montane forests of Argentina and Bolivia. We assessed the conservation status of the species in Argentina based on a detailed review of available information and an extensive survey throughout its range. A total of 6,015 individuals were detected in 14 sites, eight of which are new localities. The total number recorded in this study represents less than a third of the number exported from Argentina between 1985 and 1989 (18,641), indicating a significant reduction in population size. Research needs to be extended to additional sites, especially in Bolivia, to assess further the global status of the species, and high priority given to the creation of state and private reserves for the species.


2004 ◽  
Vol 14 (4) ◽  
pp. 247-260 ◽  
Author(s):  
PETER G. RYAN ◽  
IAN SINCLAIR ◽  
CALLAN COHEN ◽  
MICHAEL S. L. MILLS ◽  
CLAIRE N. SPOTTISWOODE ◽  
...  

The western Angola Endemic Bird Area has 14 range-restricted species. Little is known about the conservation status of the region's birds due to the civil war that has raged in Angola for the last 27 years. The greatest diversity of restricted-range species is found in Cuanza Sul province, and given the uncertainty about their current status, many of these species are listed as Threatened. In this paper we report the first significant ornithological visits to the Gabela region since 1974. We visited an extensive scarp forest patch at Kumbira Primero, near Conda, as well as smaller forest areas along the Sumbe–Gabela and Sumbe–Seles roads. Most of the threatened species were relocated, including several species not seen since the 1970s. Gabela Bush-shrike Laniarius amboimensis was common and Monteiro's Bush-shrike Malaconotus monteiri was fairly common in degraded secondary forest, old coffee plantations and primary forest at Kumbira. Pulitzer's Longbill Macrosphenus pulitzeri was fairly common at higher elevations at Kumbira as well as in the dense understorey of secondary forest west of Seles. Gabela Akalat Sheppardia gabela was less common, with only three birds found at Kumbira and one near Seles, but may have been overlooked. Only one group of eight Gabela Helmet-shrike Prionops gabela was recorded, in open woodland at the base of the scarp between Kumbira and Seles. Angola Cave-chat Xenocopsychus ansorgei was found on the rocky slopes above the forest at Kumbira. We describe the first sound recordings for five threatened species, which will help future systematic surveys of the region's forests. Vocal evidence confirms the close relationship between Gabela Bush-shrike and Lühder's Bush-shrike L. luehderi. The most pressing need is to assess the extent of remaining forests, map the distribution of key species of conservation concern, and then draft a strategy to conserve key habitat blocks.


1998 ◽  
Vol 8 (4) ◽  
pp. 349-359 ◽  
Author(s):  
Dai Bo ◽  
Simon D. Dowell ◽  
Rodney P. Martins ◽  
Robert S. R. Williams

SummaryThe critically endangered Sichuan Hill-partridge Arborophila rufipectus occupies a restricted range in south-central China. Field surveys within this range were undertaken using line transects in 1996 and 1997. Calling males were recorded from nine subtropical forest tracts within an area totalling 1,793 km2 and consisting of primary, natural secondary and replanted broadleaf forest between 1,100 and 2,235 m elevation. The only sightings obtained were in primary forest. The mean density of calling males estimated from data collected during transect surveys was 0.48 ± 0.06 and 0.24 ± 0.16 calling birds km−2 in 1996 and 1997 respectively. There was no difference in density estimates for calling males between primary forest and secondary/replanted broadleaf forest. The principal threat to the continued survival of the species is clear-felling of primary forest, but clear-felled areas are often replanted with native broadleaf trees and records of Sichuan Hill-partridge calls in such plantations offers hope for its future survival. Forest management should be modified to make forestry practices more sympathetic to the conservation of the Sichuan Hill-partridge.


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