Offshore Islets Research Articles

Samoan Archaeology—A Review of research history

Abstract:Some aspects of prehistoric material culture of Samoa were described by Buck, Thompson and Freeman in 1920s‐60s, but archaeological work did not begin until 1957, initially by Jack Golson and Wal Ambrose. Work in American Samoa was conducted by Kikuchi in 1963 and continued by Emory and Sinoto in the mid 60's. Subsequent to the independence of Western Samoa, two archaeological programs under the leadership of Roger Green in the 1960s and Jesse Jennings in the 1970s respectively have laid a firm foundation for the understanding of Samoan prehistory from an archaeological point of view. Subsequent research in American Samoa has also added to this knowledge. This review describes some of the major findings and contributions of archaeological research in Samoa and discusses important theoretical and methodical issues for future research.

Morphological variation in Gallotia atlantica from the volcanic island of Lanzarote: subspecies designations and recent lava flows

A detailed uni- and multivariate analysis of within-island geographical variation in scalation and body dimensions of the lacertid lizard, Gallotia atlantica, from Lanzarote (and two neighbouring offshore islets) was carried out. Two main morphological groupings were detected: four populations clustered within a putative malpais group, i.e. from relatively recent volcanic lava fields (seven populations were sampled from these areas), while the other 19 populations (including the three remaining malpais populations, and those from the offshore islets of Montana Clara and Alegranza) also clustered together. Thus, while there is a tendency for occupation of malpais areas to be related to morphological variation, this model does have some inconsistencies. The differentiated malpais group comprises populations from two geographically isolated areas, one from the central-western part of the island (Timanfaya) and the other from the north (Malpais de la Corona). The divergence of these populations is considered to have arisen recently, rather than their being relicts of an ancient, formerly widespread, lineage. The morphological variation partially supports the previous use of two different subspecies to describe the within-island variation. However, if such a scheme were applied then one of the subspecies would need to encompass populations from the geographically separated southern Timanfaya and Malpais de la Corona areas, as opposed to just the latter. We reject previous observations that either malpais individuals in general, or those corresponding to the north-eastern subspecies, are larger than individuals from other areas. The pattern of morphological variation of G. atlantica within Lanzarote is less pronounced but shows some similarities with patterns of morphological variation in lizards from neighbouring islands.

Contribution to the study of the flora and vegetation of the Kithira island group: Offshore islets of Kithira (S Aegean, Greece)

Panitsa, M., Bazos, I., Dimopoulos, P., Zervou, S., Yannitsaros, A. & Tzanoudakis, D.: Contribution to the study of the flora and vegetation of the Kithira island group: Offshore islets of Kithira (S Aegean, Greece). – Willdenowia 34: 101-115. – ISSN 0511-9618; © 2004 BGBM Berlin-Dahlem. Data on the flora and vegetation of seven offshore islets of Kithira Island (Prasonisi, Megali Dragonera, Antidragonera, Kapelo, Avgo, Megalo Strongilo and Lidia) are presented. 145 vascular plant taxa (species and subspecies) are reported, of which all but three are new records for these islets. The observed vegetation units and habitat types are briefly described and the ecological value and biogeographical importance of the area are identified for conservation purposes and discussed.

Seksek 'e Hatana/ Strolling on Hatana: Traditions of Rotuma and its Dependencies, with Excerpts from an Archaeologist's Field Notebook, and: Kato'aga: Rotuman Ceremonies (review)

These two books offer readers glimpses of Rotuman narrative and ceremonial practices. Seksek 'e Hatana begins the task of creating a cultural geography by tying oral traditions to the landscape of Rotuma and its offshore islets, whileKato'aga details the occasions and customs associated with collective celebrations. Both works contain some materials in the Rotuman language with translation into English and provide a glossary at the end of the volume. Each work also provides an overview of indigenous spiritual beliefs essential as an encompassing framework for interpreting the descriptions of events and translations of the verbal arts. Parke opens with this section, while Inia appends it to her chapters.

Contribution to the study of the flora and vegetation of the Kithira island group: Offshore islets of Kithira (S Aegean, Greece).

Panitsa, M., Bazos, I., Dimopoulos, P., Zervou, S., Yannitsaros, A. & Tzanoudakis, D.: Contribution to the study of the flora and vegetation of the Kithira island group: Offshore islets of Kithira (S Aegean, Greece). — Willdenowia 34: 101–115. — ISSN 0511-9618; © 2004 BGBM Berlin-Dahlem.Data on the flora and vegetation of seven offshore islets of Kithira Island (Prasonisi, Megali Dragonera, Antidragonera, Kapelo, Avgo, Megalo Strongilo and Lidia) are presented. 145 vascular plant taxa (species and subspecies) are reported, of which all but three are new records for these islets. The observed vegetation units and habitat types are briefly described and the ecological value and biogeographical importance of the area are identified for conservation purposes and discussed.

Floristic investigation of Lemnos island (NE Aegean area, Greece)

Abstract Panitsa, M., Snogerup, B., Snogerup, S. & Tzanoudakis, D.: Floristic investigation of Lemnos island (NE Aegean area, Greece). — Willdenowia 33: 79–105. 2003. — ISSN 0511-9618; © 2003 BGBM Berlin-Dahlem. Lemnos island and its 10 offshore islets belong to the Prefecture of Lesvos and biogeographically to the N Aegean area. In comparison with other islands of the N Aegean area, Lemnos is characterized by an intense horizontal relief, absence of limestone cliffs, low land formations (highest point 429 m), medium inclination and intense human interference (agriculture, stock farming) almost on the entire island. Including the data from the available literature and the authors’ investigations, the flora of the area consists of about 681 plant taxa. The dominance of the Mediterranean elements and therophytes reflect the Mediterranean character of the Lemnos flora. Although its flora is rather poor, Lemnos conserves a high level ecological value based on the existence of a variety of different vegetation...

Sex and age differences in distribution, abundance, and habitat preferences of wintering Harlequin Ducks: implications for conservation and estimating recruitment rates

We determined the sex- and age-specific distribution, abundance, and habitat preferences of wintering Harlequin Ducks (Histrionicus histrionicus) and evaluated potential biases in measuring ratios of immature males to adult males to estimate recruitment rates. A comparison of the occurrence of birds with habitat availability at the 1-km scale indicated a preference for wide intertidal habitat with cobble–gravel or bedrock–boulder substrate, small offshore islets and shoreline with attached or nearby reefs and islets, areas without streams, and areas with a greater historical abundance of herring spawn. Where the substrate was bedrock–boulder, birds preferred areas with tidal rapids. Densities of birds were highest along linear and complex shorelines with reefs or islets where intertidal habitat was >100 m wide and substrate was cobble–gravel or bedrock–boulder. Patterns of habitat use among sex and age classes were the same at the 1-km scale but differed at smaller scales, with adult and immature males occurring farther offshore than females. Age ratios varied among areas and were biased by survey method and misidentification of distant birds. Correcting for detected biases gave an estimated male age ratio of 9.8%. Calculated estimates of female recruitment suggest a declining population, but it is necessary to incorporate emigration in estimates of adult survival before demographic trends can be confidently inferred.

A Potential New Colony of Ashy Storm-petrels on the Mainland Coast of California, USA

Abstract We report evidence of likely nesting of the Ashy Storm-petrel (Oceanodroma homochroa) on islets adjacent to Vandenberg Air Force Base in northern Santa Barbara County, California, USA. Ten storm-petrels, along with extensive suitable habitat in the area, suggest a small colony of breeding birds. Other offshore islets along California’s central coast might hold small numbers of storm-petrels. In addition, there are possibly breeding storm-petrels in suitable remote mainland areas, such as at Vandenberg Air Force Base.

Resolving Long-Term Change in Polynesian Marine Fisheries

There is growing evidence that patterns of marine fisheries on some Pacific islands underwent significant changes over the period of human occupation. One such island is Aitutaki in the Southern Cook Islands. Over the millennia of human occupation, there were shifts in habitat use, changes in targeted prey, and the abandonment of some fishing technologies. However, the most striking trend was an apparent decline in fishing altogether. This paper brings together several lines of evidence in an effort to understand why fishing became less important on this small Polynesian "almost-atoll." The possibility of over-harvesting or resource depression is considered. Resource depression could have been a factor at one mainland locality, where occupations were at least semipermanent, but was apparently not involved in declines at an offshore islet site where occupations were short term but intensive. However, fishing on the offshore islet, and deeper water fishing in general, may have been adversely affected by the loss of a key raw material traditionally used for fishhooks, namely pearlshell (Pinctada margaritifera). Further consideration of the offshore islet assemblages is assisted by mtDNA analyses, which have allowed for species level determinations within a key family, the Serranidae. Considering the suite of changes as a whole, the costs of fishing apparently increased significantly over the 1000-year period of occupation. What is less certain is the potential role that terrestrial components (i.e., agriculture and animal husbandry) of subsistence played in fishing declines. Stable isotope studies, now underway, may further elucidate the relationships between marine and terrestrial components of subsistence.

Comparison of Managed and Unmanaged Wedge-Tailed Shearwater Colonies on O'ahu: Effects of Predation

On O'ahu, Wedge-tailed Shearwaters (Puffinus pacificus) and other seabirds nest primarily on small offshore islets, but fossil evidence shows that many seabirds formerly bred on O'ahu itself. Predation by introduced mammals is suspected to be the primary factor preventing shearwaters and other seabirds from reestablishing large nesting colonies on O'ahu. We investigated the effects of predation on Wedge-tailed Shearwaters by comparing three small unmanaged colonies at Malaekahana State Recreation Area on O'ahu, where feral cats are fed by the public, with a large managed colony at nearby Moku'auia Island State Seabird Sanctuary, where predators are absent. During three visits on 19 April, 16 June, and 23 October 2000, we located 69 occupied burrows in three colonies at Malaekahana and 85 occupied burrows in four monitoring plots at Moku'auia. Many more nests produced chicks at Moku'auia (62%) than at Malaekahana (20%). Among plots at Malaekahana, reproductive success was lowest (zero) at the colony closest to the cat feeding site. In addition, 44 adult shearwater carcasses were found at Malaekahana near the cat feeding site. Predation, most likely by cats attracted to supplemental food, had a devastating impact on shearwaters at Malaekahana. At one colony there was complete reproductive failure and almost all adults were killed. Populations of long-lived species like seabirds are sensitive to adult mortality, and Malaekahana may act as a sink, draining birds away from other areas.

The scolopendromorph centipedes of Mauritius and Rodrigues and their adjacent islets (Chilopoda: Scolopendromorpha)

The results of a survey of the scolopendromorph centipedes of Mauritius and Rodrigues and their offshore islets for surviving endemic species are reported. This fauna was poorly known, only five species having been reported from the islands. Collections were made from Mauritius and Gunner's Quoin, Round Island, with its remnant of palm savanna, Serpent Island and Île aux Aigrettes which contains the last remnant of coastal forest. Collections were also made on Rodrigues and two small coral sand islets — Île aux Sables and Île Cocos. Eight species were recorded from Mauritius. Rhysida longipes longipes (Newport, 1845), a widespread tropical species and Cryptops decoratus Lawrence, 1960, hitherto known from Madagascar, are new records and two new endemic species are described: Rhysida jonesi, from Round Island and Cryptops daszaki, found only on Île aux Aigrettes. This brings the number of endemics to four. Further material of the upland forest endemic Cryptops mauritianus Verhoeff, 1939 was obtained and the species redescribed. The characteristics of Otostigmus rugulosus Porat, 1876, a widespread species first described from Mauritius, are discussed. Four species were found on Rodrigues of which Otostigmus rugulosus and Cryptops niloticus Lewis, 1967 are new records. Both are widespread species. No endemics were found, probably reflecting the denuded state of the vegetation. A key is provided for the identification of the 10 species from the islands. The differences between the Cryptops species are discussed as is the distribution of scolopendromorphs on the islands. Coverage of the islands is still poor and further collection is desirable.

The use of allozymes and shell morphology to distinguish among sympatric species of the rock oyster Saccostrea in Thailand

Three hundred and fifty-five Saccostrea oysters from 12 sites throughout Thailand were scored for allozyme variation at eight enzyme loci ( Aat-1, Ap, Est-2, Lap, Mdh-1, Mpi, Pgi and Pgm). Allelic variation within Lap, Pgi, Pgm and Mpi loci was concordant. Principle component analysis (PCA) of these four loci identified two principal components (PC1 and PC2) that resolved individuals into three discrete clusters corresponding to different species. Oysters were assigned to different species by diagnostic alleles at Lap, Mpi and Pgi loci, and correct identification confirmed by a comparison of observed genotype frequencies in putative single-species samples with those expected under Hardy–Weinberg equilibrium. We identified one of these species as Saccostrea commercialis, based on identical mobility's at all eight loci to a reference sample of that species from Australia. The other two species we identified as S. cucullata and S. manilai by comparison of relative allozyme mobility's and shell morphology traits with data published for these species. S. commercialis and S. manilai were found in sympatry in coastal and estuarine sites throughout the Gulf of Thailand. S. cucullata was restricted to offshore islets. Ten measurements were made on the shells of a subset of oysters from seven sites. Observations were also made of adductor scar colour and chomata spacing. Principal component analysis of shell morphometrics of ninety oysters identified by allozymes revealed three principal components that varied between species. These reflected variation in overall size, degree of “cupping” of left valve, and relative size of the umbo cavity. The most useful character for species identification was the size of the umbo cavity, which was large in S. cucullata and S. commercialis, but almost non-existent in S. manilai. Mean umbo depths were 1.49 cm for S. cucullata, 0.7 cm for S. commercialis and 0.42 cm for S. manilai. Colour of the adductor scar was also of taxonomic value, with 75% of S. cucullata having black scars, while scars were white or brown in the other two species.

The Indian Ocean Coast of Somalia

Somalia has the longest national coastline (3025 km) in Africa with an estimated shelf area (depth 0–200 m) of 32 500 km 2. The country is divided into the northern coastal plain of Guban, which has a semi-arid terrain; the northern highlands with rugged mountain ranges containing the country’s highest peak (2407 m); and the Ogaden region which descends to the south from the highlands and which consists of shallow plateau valleys, wadis and broken mountains. The latter region continues to the Mudug plain in central Somalia. From Ras Caseyr to the Kenya border, the coast runs north-east to south-west, coinciding with the displacement caused by the Mesozoic marginal subsidence. This general structure is complicated by sedimentary troughs crossing the Horn of Africa, and by large sedimentary basins, cutting the coastline and extending inland into Southern Somalia and Northern Kenya (Juba–Lamu embayment, Mogadishu basin). Offshore, the western Somali Basin extends from Socotra to the Comores. The open shelf environments developed along the Somali coast are a consequence of an extensive marine transgression, connected to coastal subsidence or inland uplift. The rocks along the southern coastal belt are Pliocene–Pleistocene, and are characterized by a sequence of both marine and continental deposits of skeletal sands, coral build-ups, eolian sands and paleosols. As well as eolian and biogenic sedimentary processes, sea-level fluctuations, Holocene climatic changes and neotectonic movements have combined to produce the modern coastline. A notable feature is an ancient dune ridge complex, known as the Merka red dune, which rims the coast extending beyond the Kenyan border and which separates the narrow coastal belt from the Uebi Shebeli alluvial plain. Two features of note are the Bajuni Archipelago, which consists of islands, islets and skerries, forming a barrier island separated from the coast by a narrow marine sound, and a braided, channelized coastal area, which originated from the drowning of a paleofluvial net. The southern Somali coast, with that of Kenya and Tanzania, forms part of the Somali Current Large Marine Ecosystem, encompassing 700 000 km 2, and extending 800 km between Dar es Salaam and Ras Hafun. Abundant biomass develops here due to upwelling. The shelf area has a wide variety of coral reefs, mangroves, seagrass meadows, beaches and estuaries. In shallow water areas the abraded flats are colonized by scattered coral communities with variable cover. A true fringing reef is achieved in places only in the Bajuni archipelago. All along the southern Somali coastal shelf there are spreading meadows of Thalassodendron seagrass, and benthic communities typical of mobile sandy substrates are limited to beach ridges and shoals developed along the coastline. Around the Bajuni barrier island and the channelized area there is more diversity. Mangroves grow on the tidal belts of the channels, and there are expanses of salt flats. Large-scale alteration produced by man on the Somali coast is relatively recent, but has accelerated in the last few decades, especially around major cities. This alteration affects especially backshore areas where the Pleistocene coral reefs are quarried. At present, the continental shelf is not adequately monitored or protected, so coastal habitats are being degraded, living marine resources are overexploited, and pollution levels are increasing, all of which affect natural resources and biodiversity. Somalia is one of the world’s poorest and least developed countries, with few resources and devastated by civil war, but since 1993 it has been part of the Common Market for Eastern and Southern Africa (COMESA). This will affect fisheries and aquaculture in terms of the investment, production, trade and fish consumption of the member states. There are currently no marine protected areas and no legislation concerning their establishment and management, although the World Conservation Monitoring Centre (WCMC) Protected Areas Database lists Busc Busc Game Reserve as an MPA. In 1992, The WCMC also listed the following coastal sites as proposed protected areas: Zeila (important sea bird colonies on offshore islets), Jowhar–Warshek, Awdhegle–Gandershe. The area from Kisimayo to Ras Chiambone is probably of highest priority, as it is important for coral reefs, marine turtles, and mangrove resources, although it is still poorly known.

Nusa Roviana: The Archaeology of a Melanesian Chiefdom

When European traders started to expand their economic activities in the Solomon Islands in the early 19th century, they found indigenous groups already engaged in long-distance exchange. Amongst the most powerful of these were the Roviana chiefs whose bases were situated on the shores and offshore islets of Roviana Lagoon on the island of New Georgia. Power in Roviana was bound to a cycle of headhunting raids, ritual violence, ancestor cults, and the circulation of shell valuables. Today, the archaeological record of the Roviana chiefdom consists of spectacular and well preserved surface elements consisting of domestic and religious architecture, fortifications, and a rich array of material culture. This surface record poses specific problems of interpretation and dating, but spatial archaeological methods combined with oral traditions and historical accounts allow this record to be unraveled. This paper describes the structure of a late period Roviana settlement with an emphasis on the symbolic dimension of the cultural landscape. It also discusses the archaeological evidence for change in the political, economic, and ideological dimensions of Roviana life in the centuries preceding its entanglement with the West.

Post-collisional magmatism around northern Taiwan and its relation with opening of the Okinawa Trough

Being part of an active mountain belt formed by oblique collision of the Luzon arc with Asia, northern Taiwan and the offshore islets are marked by a series of latest Pliocene–Quaternary volcanoes whose eruptions have been conventionally ascribed to westward propagation of the Ryukyu volcanic arc. On the basis of new geochemical data, along with supporting geologic and geophysical evidence, we propose instead that this young volcanism resulted from post-collisional lithospheric extension in the northern Taiwan mountain belt and the mantle source regions involved in the melt generation have been significantly modified by the nearby Ryukyu subduction-related processes. Magmas thus produced through the northeast to the southwest in the Northern Taiwan Volcanic Zone (NTVZ) vary from low-K to calc-alkaline and then shoshonitic compositions. Such a spatial geochemical variation, characterized by southwestward increase in enrichments of potassium and incompatible trace elements, runs subparallel to the southwestern part of the present-day Ryukyu Trench. The geochemical variation that can be explained by southwestward decrease in degrees of partial melting of the mantle sources is reconciled with a southwestward-weakening extensional regime observed in the NTVZ. The post-collisional extension in northern Taiwan, furthermore, might have played a role in reactivation of the opening in the middle Okinawa Trough, and gave way to its rapid southwestward propagation with associated development of the Ryukyu subduction zone west of ∼124°E. This nascent subduction, in turn, resulted in abundant submarine volcanoes which delineate an embryo volcanic front along the southern margin of the trough. Therefore, the southwestern Okinawa Trough is not a `fore-arc' basin as had been previously alleged, but represents an `atypical' back-arc basin which developed broadly synchronously or prior to its arc–trench system in this particular collision/extension/subduction tectonic environment.

Land snails on Porto Santo: adaptive and non-adaptive radiation

A survey has been made of the land snail fauna of Porto Santo, Madeiran archipelago. Porto Santo is an isolated island about 12 km long by 5 km wide. The fauna is exceptionally species-rich and characterisied by radiations of species in several families, especially the Helicidae. Sixty-five samples from the mainland and five offshore islets yielded 56 species, 84% of them endemic, with a mean of 11.5 species per site, and marked regional differentiation in faunal composition. A given site produces on average only approximately one fifth of the number of species possible, equivalent to a value for Whittaker’s index of diversity of 4.5. Patterns of localization occur on the peaks to the east and west of the island, with numerous cases of replacement by congeneric and morphologically similar species. Local areas have assemblages of species differing in shell size and shape, which probably exploit different niches, the pattern in one area paralleling that in others. The low-lying sandy areas which separate these areas are now unfavourable to many endemic species; those which do occur in them tend to have island-wide distributions. Morphological variation in such species appears to have ecological rather than geographical correlates. We conclude that adaptive responses have occurred, but that much of the species richness can be interpreted as non-adaptive, that is, due to allopatric divergence in isolation by species which retain similar niches. Even on so small a land mass the topography is such that for many land molluscs it represents a cluster of refuges intermittantly connected through impermanent and often unfavourable sandy environments, on each of which evolution proceeds independently. Differences in distribution patterns between families probably arise because they evolved at different times in the island’s history. These results are compared with those from snail faunas in other parts of the world, some of which are similar to them.

VARIATION IN SNAIL SPECIES WIDESPREAD ON PORTO SANTO, MADEIRAN ARCHIPELAGO

Shell variation has been studied in two widespread land snails from Porto Santo, Madeiran archipelago: the helicid species or species complex Heterostoma paupercula (Lowe) and the clausiliid species Boett-geria lowei Albers. Samples were collected from the mainland and the offshore islets from sea level to the highest altitude. Shell size, colour and presence or absence of penstome teeth were scored in H. paupercula and some individuals were dissected to examine genitalia. Shell size and rib number were scored in B. lowei. In B. lowei size declines and rib number increases with altitude. In H. paupercula samples from sandy locations have a larger shell size and a higher frequency of pale colour than those from non-sandy locations. On average, sandy sites have a lower altitude than non-sandy ones, however, so that these two variables are confounded. The survey shows that shell characters of a kind used in taxonomy are subject to variation associated with ecology, this must be borne in mind when assessing present-day taxa and morphological change through the fossil sequence. The data for H. paupercula support the conclusion that it is a single species variable in shell characters and polymorphic for hemiphally.

Fission-track dating of volcanics in the northern part of the Taiwan-Luzon Arc: eruption ages and evidence for crustal contamination

Igneous rocks from the Coastal Range and offshore islets of eastern Taiwan, Camiguin island and northern Luzon of the Philippines, which collectively constitute the northern part of the Taiwan-Luzon Arc, have been dated by the fission-track technique. The pooled ages range widely from 49.9 Ma to 0.02 Ma. Some of the samples produce bimodal or even multiple age distributions in composite probability density plots, indicating the presence of inherited “ages” in the dated zircons. A χ 2 test shows that most of the χ 2 ages are in good agreement with the youngest peak date. Except for one intrusive basement sample and five volcanic samples affected by hydrothermal alteration, most of the χ 2 ages can be interpreted as the ages of volcanic eruptions. The inherited ages of the zircon populations present in many samples record thermal activities which occurred prior to the eruption of their host magmas. This suggests that upper level crustal contamination has taken place, thereby introducing some xenocrystic zircons into the magmas erupted. The fission-track ages are always younger than or occasionally equal to the ages obtained by other methods for the samples from the same localities. Of six samples dated by the ArAr stepwise heating method four samples have plateau age close to the FTD ages. Some samples do not contain inherited, partially annealed FTD ages and the corresponding KAr ages are consistent with the FTD ages. A detailed study of Rb Sr isotopic systematics of phenocryst minerals by Lan C. Y., Shen J. J. S. and Lee T. (1986). A RbSr isotopic study of andesites from Lutao, Lanhsu, and Hsiao-Lanhsu, eruption ages and isotopic heterogeneity. Bull. Inst. Earth Sci. 6, 211–226 showed isotopic disequilibrium suggesting retention of unequilibrated older volcanic products. Many of the KAr dates, which are commonly older than the eruption ages determined by the FTD technique, may reflect inherited argon. Based on results from a combination of dating methods, volcanism in the northern part of the Taiwan-Luzon Arc can be deduced to have been active since 26 Ma. The igneous activity in the Taiwan Segment (northern part of North Luzon Arc as exposed in the Coastal Range) ceased at 2.2 Ma, because of the arc-continent collision. Further southward, away from the present location of the collision zone, the volcanoes are still active.

The status and conservation needs of the terrestrial herpetofauna of the windward islands (West Indies)

Current status reports are presented for the amphibians and reptiles of Dominica, Martinique, St Lucia, St Vincent, the Grenadines, Grenada and Barbados. The five islands with central peaks over 800 m have very similar herpetofauna communities in ecological terms (13–16 native species) but similar niches are often filled by distinct taxa. Barbados has a naturally depauperate fauna (nine native species). All six major islands have single-island endemic reptile species—a total of 19 endemics. Only Martinique has suffered extinctions of endemic species, although other islands have species now greatly reduced in range or surviving only on offshore islets. The value of offshore islets for reptile conservation is high. The most endangered reptiles are the diurnal species that live in xeric, coastal habitats. There is no conclusive evidence for the widely reported role of introduced mongooses in the decline of the islands' reptiles.

Lead, mercury, and cadmium in feathers of tropical terns in Puerto Rico and Australia

Levels of lead, cadmium, and mercury were examined in breast feathers of terns nesting on offshore islets near Culebra, Puerto Rico and on Michaelmas Cay and Heron Island on the Great Barrier Reef, Australia. Levels of all metals in these tropical terns were predicted to be lower than those of terns nesting in temperate regions, because the tropical species feed offshore of non-industrial areas where contamination should be less than for temperature-nesting species that feed in inshore estuaries near industrialized areas. This prediction was not supported by the evidence. In Puerto Rico, lead and cadmium levels were highest in bridled tern (Sterna anaethetus), and mercury levels were highest in sooty (S. fuscata) and roseate tern (S. dougallii). In Australia, levels of lead and mercury were higher in black noddy (A. minutus) and lower for sooty tern; and cadmium levels were highest for brown noddy (A. stolidus) and sooty tern, and lowest for black noddy. Metal levels for the tropical terns nesting in Puerto Rico and Australia generally were not lower than levels reported for temperate-nesting or mainland nesting birds (except for mercury in Australia).