Black-naped Tern Research Articles

Evidence of Hybridization between Black-Naped Tern (Sterna sumatrana) and Roseate Tern (Sterna dougallii) at St François Atoll, Seychelles

Evidence of Hybridization between Black-Naped Tern (Sterna sumatrana) and Roseate Tern (Sterna dougallii) at St François Atoll, Seychelles

KEANEKARAGAMAN SPESIES BURUNG DI HUTAN MANGROVE PULAU KELAGIAN BESAR PROVINSI LAMPUNG

The existence of mangrove forests is very important in an area because as a habitat for various types of wildlife, especially birds. This study aims to determine the diversity of bird species in the Kelagian Besar Mangrove Forest, Lampung Province. Data on bird species diversity was obtained by the IPA (Indices Ponctual Abundance) method. Data collection of bird species by recording the type and number of individual birds found. Species identification also uses the method of bird recognition directly by people who know the birds in the area such as the local community or an expert on birds. Data obtained in the field are then analyzed using the Shanon-Winner diversity index formula. The results found 27 species of birds from 21 families with a total of 741 individual birds in the Kelagian Besar Mangrove Forest. While the diversity index value is 2.26 with medium index criteria. There are 8 protected bird species, namely the black-necked darautaut (Sterna sumatrana), the white-wing daralaut (Chlidonias leucopterus), the oyster daralaut (Gelochelidon nilotica), the white belly eagle (Haliaeetus leucogaste), the brontok eagle (Spizaetus cirrhatus), oyster belly Rhipidura javanica), sabine seagulls (Xema sabini), and large fissures (Fregata minor).

Bird community structure of small islands: a case study on the Pahawang Island, Lampung Province, Indonesia

Small islands are extremely vulnerable to ecosystem disturbances. One of the common factors im-pacting on island ecosystems is the rise of tourism activity and the associated conversion of man-grove forest’s function into tourism’s supporting facility. Those changes will ultimately affect the diversity of bird species inhabiting the island.  Therefore, this study aimed to analyse the structure of a bird community in the mangrove forests of the Pahawang Island. The study used the transect method with tracking implemented. The obtained data were analysed using the Shannon-Wienner diversity index. We recorded 28 species from 21 families. Out of 21 families, Columbidae had the highest number of species (three species). Seven feeding guilds were observed during the present study, the maximum number of species belonged to the insectivore group and the minimum – to the nectarivore and omnivore (1 species each) guilds. Based on the abundance rank, the most abundant species was the cave swiftlet (Collochalia linchi). Three of the recorded species are listed in the cat-egory “Protected” according to the Indonesia Law: the brahminy kite (Haliastur indus), sunda pied fantail (Rhipidura javanica), and the black-naped tern (Sterna sumatrana). All bird species that have been recorded during the present study is classified as “Least Concern” in the IUCN Red List. The values of the Shannon-Wienner index suggest neither high nor low diversity (H’ = 2.55). Mangrove forest ecosystems, including the mudflat on the Pahawang Island, are important supporting popula-tions of wild birds through providing foraging, roosting and nesting sites. 

Migration of black-naped terns in contrasted cyclonic conditions

Cyclones are currently increasing in frequency and intensity across the tropical regions, and such changes in cyclonic activity can adversely impact tropical marine ecosystems. To examine the potential effects of these changes on marine migrations, we tracked the annual at-sea distribution of black-naped terns from Okinawa Islands, southwest Japan (26.5° N; 127.9° E). Using light-based geolocation loggers, we compared the migration chronology of six terns between 4 years of contrasted conditions regarding cyclones (regionally called typhoons). Shortly after breeding (30 August ± 13.9 days), the birds undertook their migration across the Philippine Sea to coastal regions of Borneo and Sulawesi Islands, and seemed able to avoid or cross the storm systems. The two birds tracked in years of medium–high typhoon activity (2012–2014) seemed to target a stopover area in the northern Philippines several days after a typhoon hit. By contrast, in 2017, no strong typhoon hit in August and the four study birds showed later departure by 23.8 days, but moved significantly quicker, with little or no stopover. Arrival date at the wintering site was similar among years (1 October ± 3.5 days). Terns thus show remarkable variability in their migration chronology, presumably linked with annual storm frequency. However, the limits to this variability are currently unknown. Further, if individuals respond to environmental cues to time their migration to potentially benefit from lagged optimal feeding conditions en route, it is likely that the increase of back-to-back cyclonic events in the region may reduce the benefits of such a strategy for surface-feeding predators.

Notable recent records of terns, gulls and skuas in southern Mozambique including the first country records of Black Tern Chlidonias niger

Interesting sightings in southern Mozambique of 13 species of terns, gulls and skuas are reported, the result of regular observations between October 2010 and September 2017 while I was based in the capital, Maputo. These include the first two records of Black Tern Chlidonias niger, the first fully documented record of Lesser Noddy Anous tenuirostris and the first observations of live Arctic Terns Sterna paradisaea for Mozambique, as well as status updates for Kelp Gull Larusdominicanus, Lesser Black-backed Gull L. fuscus, Sabine's Gull Xema sabini, Gullbilled Tern Gelochelidon nilotica, Swift Tern Thalasseus bergii, Sooty Tern Onychoprionfuscatus, Common Tern Sterna hirundo, Black-naped Tern S. sumatrana, Roseate Tern S. dougallii and Subantarctic Skua Stercorarius antarcticus in southern Mozambique.

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 Avifauna of the Chesterfield Islands, Coral Sea: Current Population Sizes, Trends, and Threats

This paper reports on post-1991 census data and on the breeding phenology of seabirds of the Chesterfield-Bampton and Bellona groups of coral islets in the Coral Sea. In total, 13 resident bird species were observed [Wedge-tailed Shearwater (Puffinus pacificus), Masked Booby (S. dactylatra), Brown Booby (Sula leucogaster), Red-footed Booby (S. sula), Lesser Frigatebird (Fregata ariel), Great Frigatebird (F. minor), Black Noddy (Anous minutus), Brown Noddy (A. stolidus), Crested Tern (Sterna bergii), Sooty Tern (S. fuscata), Fairy Tern (S. nereis), Black-naped Tern (S. sumatrana), and Buff-banded Rail (Gallirallus philippensis)]. Segregation for nesting habitat was similar to that previously observed on other coral-reef islets of the Coral Sea. Breeding periods were either in the winter (Masked and Red-footed Boobies, Frigatebirds, Fairy Tern) or in the summer (Wedge-tailed Shearwater, Black and Brown Noddies, Crested and Black-naped Terns) or year-round (Brown Booby). Sooty Terns bred twice a year (summer and spring), but this was not consistent across years. Estimates of breeding population sizes for the whole Chesterfield-Bampton and Bellona groups are proposed for Wedge-tailed Shearwater (90,000 to 106,000 breeding pairs), Masked Booby (280–500 pairs), Brown Booby (3,800–5,800 pairs), Redfooted Booby (7,200–7,300 pairs), Lesser Frigatebird (1,600 pairs), Great Frigatebird (350–480 pairs), Black Noddy (29,000–45,000 pairs), Brown Noddy (15,000–23,000 pairs), Crested Tern (80–100 pairs), Sooty Tern (11,000–46,000 pairs), and Black-naped Tern (70–90 pairs). Interannual fluctuation in breeding population size was apparent in Wedge-tailed Shearwater. Over the last 30 yr, an increase in Brown Booby abundance was noted, whereas declines are suspected for the Fairy Tern and Buff-banded Rail. Among the threats to nesting seabirds are stress and other disturbances caused by human frequentation, including poaching of seabird chicks and introduced mice.

First confirmed breeding record of Black-naped Tern Sterna sumatrana from St Francois Atoll and a new population estimate for Seychelles and the Afrotropical region

First confirmed breeding record of Black-naped Tern Sterna sumatrana from St Francois Atoll and a new population estimate for Seychelles and the Afrotropical region

エリグロアジサシとベニアジサシのモニタリング手法の提案―コロニー外からの観察による営巣数の計数と雛の齢査定に基づく産卵時期の推定―

エリグロアジサシとベニアジサシのモニタリング手法の提案―コロニー外からの観察による営巣数の計数と雛の齢査定に基づく産卵時期の推定―

Breeding Status of Black-naped and Roseate Terns in the Yaeyama Islands, Ryukyu Islands, Japan, in 2001

The distribution of breeding sites, number of nests, and timing of egg laying of the threatened Black-naped Tern Sterna sumatrana and Roseate Tern S. dougallii was surveyed across most of the Yaeyama Islands, located among the southern Ryukyu Islands, in the 2001 breeding season. Black-naped Terns bred in 42 sites that included 1-64 nests (average number of nests, 14.8±16.5 SD). Roseate Terns bred in six sites that included 1-123 nests (average number of nests, 59.8±57.3 SD). At most of the breeding sites, Black-naped Terns started to lay eggs in late June; while at some breeding sites, breeding commenced in early or mid July. Roseate Terns started to lay eggs in late June at two sites and in mid June at the other site.

Bird Community in Burung Island, Karimunjawa National Park, Central Java

Burung Island is one of many islands in the Karimunjawa Islands that belong to Karimunjawa National Park conservation area. The purpose of this study is to discover the structure of bird community especially the species diversity and its habitat structure in Burung Island. The study was conducted on June 2006, November 2006, and June 2007 in Burung Island. The study was conducted by using point count method. The radius of each point is approximately 20 meters, while the time interval of observation on each count is 10 minutes. Thedistance between each point in this study is 100 m. The habitat observation was conducted by using habitat profile of tree cover vertical structure which was done descriptively by looking at the function of cover level to the present of bird or the relation between level and the present of bird in that location. The study’s result indicated that there are 15 recorded bird species from 10 family in the location, in whichfive species (five family) among them are protected by the government, which are Sterna sumatrana, Egretta sacra, Nectarinia jugularis, Caloenas nicobarica, and Falco moluccensis, and two of them were included in CITES (Convention on International trade in Endangered Species) appendices 1 and 2, which are Caloenas nicobarica and Falco moluccensis. The highest values of species diversity index (H’) and evenness index (E’) can be seen from the observation’s result of June 2007, which are 1.8837 and 0.836. The habitat of Burung Island is very suitable for Caloenas nicobarica, Egretta sacra, Sterna sumatrana, and Sterna bergii as a place for breeding. The use of vegetation level by bird in Burung Island is dominated by the use of low and base levels.© 2007 Jurusan Biologi FMIPA UNS SurakartaKey words: Bird, community, Burung Island, Karimunjawa National Park

Waterbirds of the Xisha Archipelago, South China Sea

The Xisha Archipelago, South China Sea, was surveyed for waterbirds in March-April 2003 and April-August 2004. Forty-five waterbird species were recorded, making a grand total of 53 species for the Archipelago when earlier published records are included. The Archipelago is of great importance for the Red-footed Booby (Sula sula), with an estimated 10% of the world population breeding on Dong Island. Other breeding seabird species were Great Frigatebird (Fregata minor), Great Crested Tern (Sterna bergii) and Sooty Tern (S. fuscata), and it is believed that Black-naped Tern (S. sumatrana) and Roseate Tern (S. dougallii) also breed there. Compared to 1926, the number of seabirds, and the islands on which they breed, has declined greatly. The data for Ardeidae and shorebirds provide information on migration and, possibly, wintering strategies of these species. Despite habitat degradation and human disturbance, the Xisha Archipelago is still important for breeding seabirds and there is an urgent need to improve the conservation status of this bird group.

Observations on the status of the land birds, wading birds and seabirds of Samoa

This paper reports my observations during 1994–97 for both American Samoa and [W] Samoa. New waders added to the Samoan list are Wood Sandpiper (Tringa hypoleucos), Red-necked Stint (Calidris ruficollis), and Red Knot (Calidris canutus). The new breeding records are for the Black-naped tern (Sterna sumatrana), Bridled Tern (Sterna anaethetus), the Common Noddy (Anous stolidus), Crimson-crowned Fruit Dove (Ptilinopus porphyraceus) and the Red-headed Parrot-finch (Erythura cyaneovirens), in Samoa. Crested terns (Sterna bergii), Brown Boobies (Sula leucogaster) and Fairy Terns (Sterna nereis) were also observed with juveniles and so must be regarded as possible breeders in one of the Samoas.

Variable Success in Breeding of the Roseate TernSterna dougalliion the Northern Great Barrier Reef

Breeding of Roseate Terns Sterna dougallii on the northern Great Barrier Reef (11°-15°S) was monitored between 1976 and 1994, and they were recorded breeding on the inshore rocky islands in most years, usually starting April-May. Between 50-5000 pairs were recorded breeding each year and indicate that the northern Great Barrier Reef is an important breeding area for Roseate Terns during peak years when large colonies of 1000-5000 pairs formed on low sand cays in the far northern Great Barrier Reef (11°s). On at least three occasions, breeding success was poor in these large colonies, with high mortality of the almost-fledged chicks. Growth in weight and wing length of Roseate Tern chicks was measured at Eagle Island (14°42′S) between 1983 and 1986 in order to assess the influence of food on growth rates and survival. Chicks took up to 35 days to fledge, significantly longer than the ecologically similar, more numerous Black-naped Tern Sterna sumatrana at the same site at the same time and also almost 10 days longer than Roseate Tern chicks from temperate North American colonies. These data suggest that conditions in northern Australia are rarely favourable for the rapid growth and breeding success of Roseate Terns. Pelagic fish populations around inshore islands in tropical Australia may only be able to support limited numbers of Roseate Terns during the breeding season. This makes northeastern Australian populations of this globally threatened species extremely vulnerable to changes in the availability of their prey during the breeding season.

Distribution of seabirds at sea in the Gulf of Carpentaria, Australia

The distribution and abundance of seabirds was documented at sea in the Gulf of Carpentaria in December 1990 and November 1991. Of the 17 species recorded, only the crested tern, least frigatebird, brown booby and streaked shearwater were widespread. The first three species were seen mainly in coastal waters; streaked shearwaters were seen only in the central north-western gulf. The common tern, roseate tern, little tern, sooty tern, black-naped tern, common noddy and greater frigatebird were either sparsely distributed or uncommon. The list includes five terrestrial species. The distribution of the seabirds is discussed in relation to proximity to breeding and roosting sites, food availability, the effects of discards from prawn trawling, and water currents.

Feeding and Breeding of Crested Terns at a Tropical Locality—Comparison with Sympatric Black-naped Terns

In tropical waters of the northern Great Barrier Reef, Australia, Crested Terns fed their young with prey from seven families of fish and the Order Decapoda; the majority was from the Family Clupeidae (herrings). This diet overlapped with that of the sympatric Black-naped Tern. Both species caught fish from four families in common, including pomacentrids that were a major prey item for Blacknaped Terns. Crested Terns fed their young larger prey-than Black-naped Terns and tended to feed further offshore, although their feeding ranges overlapped considerably. In each breeding season studied, laying by Crested Terns occurred after Black-naped Terns had finished. It is hypothesised that by feeding on smaller prey than Crested Terns, Black-naped Terns can reach breeding condition faster on smaller fish spawned early in the breeding season. Crested Terns may take longer to reach breeding condition feeding on small fish available early in the season or may delay breeding until fish spawned earlier in the summer season have grown to a suitable size. Crested Terns laid their eggs over short periods of not more than 27 days. This brief period at Eagle Island is shorter than that recorded at any other locality on the Australian coastline. Laying at Eagle Island was considerably more synchronous than for the whole of the central to northern region of the Great Barrier Reef. It is hypothesised that food pulses providing the resource necessary to permit breeding are brief at Eagle Island.

Population Changes, Breeding Cycles and Breeding Success over Six Years in a Seabird Colony at Michaelmas Cay, Queensland

Seabirds were counted on Michaelmas Cay every month from May 1984 to April 1990. Seven species bred during the study. The major breeding species were Sooty Tern Sterna fuscata, Common Noddy Anous stolidus, Crested Tern S. bergii and Lesser Crested Tern S. bengalensis. Silver Gull Larus novaehollandiae, Black-naped Tern S. sumatrana and Bridled Tern S. anathaetus bred in some years in small numbers. Sooty Terns had a sub-annual breeding cycle of 8.6 months duration, measured between peaks of breeding numbers, while the other species were annual breeders, five in summer and one (Silver Gull) in winter. In successive breeding cycles, the sizes of breeding populations of Sooty Tern and Common Noddy both fluctuated strongly. Crested Tern numbers increased slightly then decreased, and Lesser Crested Tern numbers increased strongly then decreased again. Average Silver Gull numbers remained fairly stable over the study period. Fledging success varied considerably among breeding cycles of Sooty Tern, Common Noddy and Crested Tern. Lesser Crested Terns bred successfully in three cycles and showed increasing fledging success over the study period. Climate had a major influence on breeding populations of Sooty Tern and Common Noddy. Three cyclones were recorded; one altered the periodicity of Sooty Tern breeding cycles and two affected its breeding numbers and success. In mid-year, prolonged periods of strong winds caused breeding failures in Sooty Tern and Common Noddy. Erosion of the cay also caused nest losses. Human disturbance had little effect on breeding populations.

Factors Influencing Egg Laying and Feeding in Black-naped Terns Sterna Sumatrana

The Black-naped Tern breeds on cays and continental islands along the Great Bamer Reef, Australia. Studies of breeding and feeding were conducted at Eagle Island in the tropical north. Nesting was recorded from September to January. Egg laying was protracted over considerable periods in two of the three seasons of study. In all three seasons the first clutches for the breeding season, and for each subsequent wave of laying, were laid within a four-day period of the new moon and the number of eggs laid per day generally peaked within a few days of the full moon. Adults fed their chicks principally on the silver schooling fish belonging to the families Engraulidae, Atherinidae and Hemiramphidae. Feeding by adults occurred mostly in association with the reef surrounding Eagle Island. Adult terns hunted most actively during the early morning and late afternoon. Chick feeding rates were affected by (1) time: rates were highest in the late afternoon and lowest in the early afternoon; and (2) tides: rates were highest on flooding tides and lowest on ebbing tides. During the summer at Eagle Island, flooding tides occurred in the early morning and late afternoon at the time of new and full moons. Food seemed particularly abundant for chicks at this time. This may also explain why egg laying was linked to moon phases, because the male must courtship-feed the female all of her fish requirements just before egg laying.

Biology and Growth of the Black-naped TernSterna Sumatrana:An Hypothesis to Explain the Relative Growth Rates of Inshore, Offshore and Pelagic Feeders

The Black-naped Tern breeds on tropical and sub-tropical islands throughout the Indian and Western Pacific Oceans. In Australian waters they are non-sedentary. They usually breed during spring and summer. The mean clutch size is about 1.5 and it is incubated for 21 to 23 days. Most Black-naped Terns hunt within two kilometres of their colonies. Young are fed often; the modal interval between feedings was four to five minutes and the mean was 49.6 minutes. They ate fish from at least 15 families and up to 10 cm long. The mean size of prey fed to chicks increased during the course of the breeding season. Nestlings were fed a greater number of small fish than were chicks (> 7 days old) and mates. The size of fish fed to chicks and mates did not differ significantly but the ones eaten by foraging adults differed significantly from those that they fed to their mates. Breeding success of Black-naped Terns was higher at Eagle Island than at One Tree Island. The major causes of mortality of eggs and chicks were predation by gulls and flooding of nesting areas. Growth rates of Black- naped chicks (inshore feeder) were faster than those of offshore and pelagic feeders. We hypothesise that the ability of parents to transport food to their young (Ricklef's power requirements model) in combination with the nutrient composition of their diets explain the non-genetic differences in the growth rates of inshore, offshore and pelagic feeders. We postulate that inshore feeders provision their young with more of the limiting nutrient per unit time by supplying their young with more food than is reauired to meet their enerev needs. Ricklefs model also accounts for the changes in.the use of foraging zones during the cburse of the breeding season.

New Breeding Localities of the Bridled Tern Sterna anaethetus and its Measurements

The first breeding record in Japan of Bridled Tern Sterna anaethetus is reported from Nakanokami-shima, Okinawa prefecture, South Ryukyus (Abe and Mano 1980). In this paper, we report two other breeding localities of the species. One is Fude Rock where we have already suggested its breeding. The survey of this area was made on 27 and 28 June 1981. Fude Rock is a small rocky islet situated 12km NE of Seto-zaki, Miyako-jima, Okinawa prefecture, having an area of 140m×70m and the altitude, 9m. There is a lighthouse on the islet. Sterna anaethetus, Sterna sumatrana, Anous stolidus and Sula leucogaster settled on Fude Rock and adjacent tiny rocks. About sixty Bridled Terns were breeding, and some of them were in incubation. Another breeding locality is Panari commonly called, Gunkan-jima, is situated near the southeastern end of Miyako-jima. We visited this area on 9 July 1981. The area is a small ring-shaped coral reef, and there are many small rocks at the eastern side of the area. Sterna anaethetus, Sterna sumatrana and Anous stolidus were observed on these rocks. About one hundred or one hundred and fifty Bridled Terns were counted, and their eggs and early chicks were found. The measurements of the Bridled Terns captured on Nakanokami-shima are given.