Low Endemic Level Research Articles

Conhecimento e uso do ouricuri (Syagrus coronata) e do babaçu (Orbignya phalerata) em Buíque, PE, Brasil

O Nordeste do Brasil abriga 80 espécies de palmeiras nativas, com baixo endemismo (27,5%), algumas delas ameaçadas pelas alterações destrutivas do habitat natural, associadas à exploração desordenada. Investigou-se do ponto de vista etnobotânico a importância do ouricuri (Syagrus coronata) e do babaçu (Orbignya phalerata) em uma comunidade estabelecida junto ao Parque Nacional Vale do Catimbau, município de Buíque, Pernambuco. A importância atribuída pelo povo local para essas espécies foi analisada sob os seguintes aspectos: número de usos, número de informantes que faziam uso de seus produtos diretos ou indiretos; grau de consenso entre os informantes referentes aos usos relatados. Os dados foram obtidos através de entrevistas semi-estruturadas (60 informantes) e de índices baseados em técnicas de consenso do informante. Foram citadas sete categorias de uso: alimento do homem; alimento de animais domésticos; alimento de animais silvestres; construção; artesanato; combustível; medicinal. Apesar da diversidade de usos (Sc = 33; Oph = 25), a importância das duas espécies está relacionada predominantemente ao aproveitamento da amêndoa, como mostram os índices de valor para frutos (Sc = 0,48; Oph = 0,56). Analisando a contribuição de cada espécie para o uso total, o ouricuri apresentou maior valor (8,58) em relação ao babaçu (6,31). Sinais de um processo de erosão do conhecimento foram observados, com vários usos apontados como não mais praticados na comunidade, particularmente os associados ao artesanato.

Prevalence of pathogenic Leptospira spp. in sheep in a sheep-only abattoir in New Zealand

AIM: To determine the prevalence of the two most commonly diagnosed pathogenic Leptospira spp. serovars, Hardjobovis and Pomona, in sheep in a sheep-only abattoir in New Zealand, and to determine the prevalence of kidneys which were leptospire culture-positive collected from sheep seropositive or seronegative to the microscopic agglutination test (MAT). METHODS: A repeated cross-sectional observational study was conducted of serological and kidney culture prevalences of Leptospira borgpetersenii serovar Hardjobovis and Leptospira interrogans serovar Pomona. Lines of sheep and individual sheep were systematically randomly selected at a sheep-only abattoir during 18 May 2004 to November 2004 and 06 December 2004 to 14June 2005. Additionally, a cross-sectional study examined prevalences in a purposively selected line of sheep from a flock with clinical evidence of an outbreak of leptospirosis. RESULTS: In the study population of 15,855 sheep of which 2,758 were sampled, 5.7 (95% CI=4.9–6.7)% were seropositive to one or both serovars; 44.2 (95% CI=34.6-54.2)% of 95 lines of sheep and 44.9 (95% CI=35.0-55.3)% of 89 farms showed serological evidence of infection. The serological prevalence of serovar Hardjobovis was significantly higher than that of serovar Pomona both at line (33% and 4%, respectively) and individual (5% and 1%, respectively) levels. A low but persistent seroprevalence of Hardjobovis throughout both years suggested low-level endemicity to this serovar, whereas Pomona infections appeared to besporadic. Leptospires were isolated from kidneys of 8/37 (22%)Hardjobovis- and 1/6 (17%) Pomona-seropositive, and 5/499(1%) seronegative animals. Of the animals purposively sampled from a farm with a clinical outbreak of leptospirosis, all kidneys from the 13 seropositive animals were culture-positive, indicating a high risk of exposure of meat workers in outbreak situations. Kidneys of MAT-seropositive sheep were 21.7 (95% CI=7.6–61.9) times more likely to test culture-positive than kidneys from animals with negative MAT titres. In general, the results indicated that 13/1,000 sheep slaughtered were potentially shedding leptospires. CONCLUSIONS: The study demonstrated the presence of a definite risk of occupational exposure of meat workers in a sheep-only slaughterhouse to the two most commonly diagnosed pathogenic Leptospira spp. serovars in New Zealand.

The relevance of data on genetic diversity for the conservation of Afro-montane regions

Molecular data are shedding new light on our understanding of genetic diversity and biological diversity in general. We examine results of recent genetic studies on African birds that document endemic diversity in small, isolated montane forests of Africa. These studies show that levels of genetic differentiation in these isolated montane regions are substantial and indicate little or no gene flow with their closest populations. Although this pattern of locally distributed montane taxa is not something that has gone unnoticed by traditional taxonomists, we argue that many of the small, often outlying areas run the risk of being devalued in conservation planning because these areas generally have comparatively low levels of overall diversity and endemism (especially at the species level). We strongly suspect that other organisms will possess similar patterns of differentiation in Afro-montane regions of Africa and we argue that this information can be effectively brought to bear to highlight the conservation significance of these smaller areas.

Vaccination and the dynamics of immune evasion

Vaccines exert strong selective pressures on pathogens, favouring the spread of antigenic variants. We propose a simple mathematical model to investigate the dynamics of a novel pathogenic strain that emerges in a population where a previous strain is maintained at low endemic level by a vaccine. We compare three methods to assess the ability of the novel strain to invade and persist: algebraic rate of invasion; deterministic dynamics; and stochastic dynamics. These three techniques provide complementary predictions on the fate of the system. In particular, we emphasize the importance of stochastic simulations, which account for the possibility of extinctions of either strain. More specifically, our model suggests that the probability of persistence of an invasive strain (i) can be minimized for intermediate levels of vaccine cross-protection (i.e. immune protection against the novel strain) and (ii) is lower if cross-immunity acts through a reduced infectious period rather than through reduced susceptibility.

Estudio descriptivo de los brotes de hepatitis A investigados en Cataluña (1999-2003)

The currently low endemic level of hepatitis A in Spain favors manifestation of the disease as outbreaks among specific risk groups. The aim of this study is to analyze the hepatitis A outbreaks investigated in Catalonia (Spain) during the period of 1999 to 2003. The criteria for including an outbreak were defined and outbreaks were classified according to the type of transmission. The variables analyzed were space, time, socio-demographic parameters, setting, risk factors, and preventive measures adopted. The incidence rate and rate ratio were calculated according to age and sex. Among 74 outbreaks, 73 fulfilled the inclusion criteria. Most outbreaks involved person-to-person transmission (83.8%) and the rest had a common source of infection (14.9%). In total, 334 cases were included (cumulative incidence 1999-2003: 5.27 per 100,000 inhabitants), with an average age of 24.5 years. The settings yielding the most cases were family (143), community (97) and schools/preschools (87). The number of cases per outbreak ranged from 2 to 11, except one outbreak that occurred in 83 young homosexual men with high-risk sexual practices. The main factors related to the case index or to coprimary cases included belonging to age groups with low immunity (children and young adults) and travelling to or from endemic areas. Hepatitis A outbreaks in Catalonia are still frequent. They mainly occur in the family environment, by person-to-person transmission and in the most vulnerable groups (preschool or school employees, travelers, and men who perform high-risk sexual practices with other men).

Controlling methicillin-resistant Staphylococcus aureus : Quantifying the effects of interventions and rapid diagnostic testing

Control of nosocomial transmission of methicillin-resistant Staphylococcus aureus (MRSA) has been unsuccessful in most countries. Yet, some countries have maintained low endemic levels by implementing nationwide MRSA-specific infection control measures, such as "search & destroy" (S&D). These strategies, however, are not based on well designed studies, and their use in countries with high levels of endemicity is controversial. We present a stochastic three-hospital model and an analytical one-hospital model to quantify the effectiveness of different infection control measures and to predict the effects of rapid diagnostic testing (RDT) on isolation needs. Isolation of MRSA carriers identified by clinical cultures is insufficient to control MRSA. However, combined with proactive search (of high-risk patients on admission and/or contacts of index patients), it will maintain prevalence levels <1%. Concerted implementation of S&D in countries with high nosocomial endemicity reduces nosocomial prevalence to <1% within 6 years. Stepwise implementation of control measures can reduce isolation capacities needed. RDT can reduce isolation needs by >90% in low-endemic settings and by 20% in high-endemic settings. Surveillance of colonization and improved hand hygiene can markedly increase control efficacy. These findings strongly suggest that: (i) causality exists between S&D and low MRSA prevalence; (ii) isolating MRSA carriers identified by clinical cultures as a single measure is insufficient for control; (iii) a combined approach of isolation and screening confers efficacy; and (iv) MRSA-prevalence levels can be reduced to <1% in high-endemic settings by S&D or a stepwise approach to interventions. RDT can markedly enhance feasibility.

An Assessment of Habitat Diversity and Transformation on La Réunion Island (Mascarene Islands, Indian Ocean) as a Basis for Identifying Broad-scale Conservation Priorities

Most natural habitat in the Mascarene Islands (Mauritius, La Reunion and Rodrigues) has been transformed. Although urbanisation, agriculture and alien plant invasions have transformed large areas in La Reunion, the island has by far the greatest area of intact habitats in the Mascarenes, but remaining natural areas are under threat. We propose a protocol for defining a system of habitat types and for using these to provide a preliminary assessment of conservation priorities for La Reunion. The protocol draws on existing data and expert knowledge to map habitat types, assesses the extent of habitat transformation, and quantifies heterogeneity between habitat types based on climate, topography and geology. The pattern of habitat transformation was uneven among the nineteen habitat types identified. While three habitats have lost > 95% of their original area, four still retain> 80% of their original extent. Habitat types could be grouped into the following categories: (i) transformed habitats with low levels of plant endemism, (ii) habitats confined to homogenous geology with high levels of plantendemism, and (iii) species-rich heterogeneous habitats on diverse geological types. Priority habitats were also identified using municipalities as a basis for implementation. Urgent action is required for several habitat types where a large part of the original extent has been transformed. Three municipalities which contain more than 10 habitat types should receive conservation priority. The analysis provides the basis for setting conservation priorities in La Reunion at the regional and local scale. Implications of the results are discussed with reference to requirements for finer-scale conservation planning.

A population based seroepidemiological survey of Chlamydia pneumoniae infections in schoolchildren

Aim: A serosurvey was carried out in schoolchildren from a northeastern area of Italy to define the burden of Chlamydia pneumoniae infection. Methods: A sample of 649 schoolchildren underwent a...

The changing pattern of hepatitis B virus infection over the past three decades in Italy

By the end of 1970s, Italy was a country at medium endemic level of hepatitis B virus infection, with wide geographical differences; intrafamily transmission was the major mode by which infection spread; hepatitis B e antigen positivity and hepatitis Delta positivity were frequently detected in hepatitis B surface antigen chronic carriers; a high proportion of subjects with chronic liver disease resulted as hepatitis B surface antigen positive. Three decades apart, the picture was completely changed, as documented by several surveys. Nowadays, Italy is a country at very low endemic level of hepatitis B, without geographical differences; the infection is mostly sexually transmitted; hepatitis B e antigen positivity and hepatitis Delta positivity are rarely detected in hepatitis B surfaces antigen chronic carriers; a low proportion of subjects with chronic liver disease result hepatitis B surface antigen positive. These important changes may be due to both non-specific (i.e. improvement in socio-demographic features) and specific (i.e. a comprehensive vaccination program against hepatitis B) preventive measures.

Fluctuations in the occurrence of Escherichia coli O157:H7 on a Norwegian farm*

To describe the distribution of Escherichia coli O157:H7 on a sporadically positive dairy farm and on possible contact farms over a one-year period. Environmental and faecal samples from all animals at the farm, and faecal samples from animals at contact farms were analysed for E. coli O157:H7 by immunomagnetic separation methods or VIDAS. Confirmed isolates were tested for cytotoxicity in the Vero cell assay and typed by PFGE. Escherichia coli O157:H7 (stx2 and eae) of the same PFGE type were isolated from cattle, sheep, hens and environmental samples at variable levels during summer and fall 2002, but were not detected in 2003. Escherichia coli O157:H7 had a widespread distribution on the farm investigated, but the original source of contamination could not be identified. The occurrence of this bacterium on the farm did not result in any detectable increase in gastrointestinal disease in the associated population. Despite a low endemic level of E. coli O157:H7 in the Norwegian cattle population, the growth and spread of this potentially important bacterium may occur.

Distribution and biogeography of Bactrocera and Dacus species (Diptera: Tephritidae) in Papua New Guinea

Abstract Based on literature records and the results of an extensive trapping program, presence records for 194 species of Bactrocera and Dacus in the 19 provinces of Papua New Guinea (PNG) are presented. Of the 770 records, over 500 are new. Based on species accumulation curves, Central, Morobe, Madang, Eastern Highlands, Western Highlands, New Ireland and Bougainville provinces, plus the province pairs of East and West Sepik, East and West New Britain, and Southern Highlands and Enga, can be regarded as having been adequately sampled. The remaining provinces should still be regarded as being under‐collected. On mainland PNG, Morobe and Central provinces have the richest faunas and highest levels of endemism, approximately 15% each. All other mainland provinces have very low levels of endemism and are essentially subsets of the faunas of Morobe and Central Province. Although also with very low levels of endemism, the Highlands provinces have a statistically distinct fauna, suggesting that a pool of the PNG species are able to utilise both lowland and highland habitats. The fruit fly fauna of the island provinces is distinct from the mainland fauna, with further separation between the islands of the Bismark Archipelago (New Britain and New Ireland) and Bougainville. The greatest diversity of flies in PNG are associated with major northern geological elements, i.e., the New Guinea orogen, New Guinea accreted terranes and the off‐shore islands, rather than the primary southern geological element, the Australian creton.

Infection rate and spontaneous seroreversion of anti-hepatitis C virus during the natural course of hepatitis C virus infection in the general population.

Hepatitis C virus (HCV) infection is common worldwide but there are different prevalence rates in different countries. Data on the incidence of HCV in the general population are scarce. Spontaneous viral clearance occurs in 10-25% of infected individuals after acute infection yet controversy exists regarding the frequency of spontaneous clearance during the natural course of HCV infection in the general population. Anti-HCV prevalence, HCV infection rate, and the kinetics of anti-HCV were studied in a cross section of the general population of central Italy. Anti-HCV prevalence (EIA-3 Ortho, RIBA-3 Ortho Chiron) was estimated in 3884 randomly selected individuals. Infection rate and antibody kinetics were estimated in 2032 participants for whom a second blood sample was taken after a median follow up of seven years. HCV-RNA determination by polymerase chain reaction was performed on follow up sera. The overall confirmed anti-HCV prevalence was 2.4%. Two participants seroconverted for anti-HCV, giving an overall infection rate of 1.4 cases per 10 000 person years (95% confidence interval 0.2-5.2 per 10 000 person years). Of the 36 individuals confirmed as anti-HCV positive at enrollment, seven (19.4%) showed complete seroreversion. Seven (87%) of the eight individuals with indeterminate results at enrollment were serologically non-reactive at the end of follow up. Of the 25 participants confirmed to be anti-HCV positive at both enrollment and follow up, 23 (92.0%) with stable serological profiles tested positive for HCV-RNA at the end of follow up. There is still a permanent risk, although low, of HCV spread in the general population in an area of low level endemicity. In this setting, a wide spectrum of modifications of viral and antibody patterns can be observed in HCV infected patients.

Relationship between spruce beetle and tomentosus root disease: two natural disturbance agents of spruce

This project investigated the interaction between tomentosus root disease of spruce, caused by Inonotus tomentosus (Fr.:Fr.) S. Teng, and spruce beetle (Dendroctonus rufipennis (Kirby)). Both organisms are important agents of mortality and volume loss in boreal and sub-boreal spruce forests of British Columbia. They also occur in similar stand types with respect to species composition and tree age. One study involved an intensive survey of 23 spruce stands, where trees were sampled for both beetle and root disease. Tree condition (dead standing, live, windthrown) was also recorded. Few stands showed a significant relationship between incidence of spruce beetle and incidence of root disease, regardless of tree condition. Observations indicated that beetles actually tended to avoid severely infected trees. A second study involved pheromone baiting of paired healthy and infected trees, and measurements of phloem thickness. Two sites were used, one with very high (epidemic) populations of beetles, and the second with low (endemic) levels. Spruce beetle attacks were more successful on infected trees compared with healthy trees only at the site with endemic levels of beetle. Collectively, the results indicate that tomentosus root disease helps to maintain endemic levels of spruce beetle, and disease incidence may be useful as a tool to identify areas that may have endemic populations of spruce beetle.

Rationale for mass antibiotic distribution for trachoma elimination.

Rationale for mass antibiotic distribution for trachoma elimination.

Echinococcosis: A Drop of Water???Review on Human Disease, Diagnosis, and Management

Summary Echinococcosis continues to be a serious public healthproblem throughout the world, especially in sheep-herding areas. Diagnosis should be suspected whenthere is a history of living in, or travel to, an endemicarea in the setting of a characteristic imaging study.Treatment should be tailored for each patient giventheir unique risks and benefits, but most should onlyreceive treatment if symptomatic. Through aggressivevaccination, education, and canine medication, oneday echinococcosis may be as out of date as hydatid isfor a “drop of water.”AcknowledgmentsWe thank Andrew Rhymer for the illustrations and James El-lzy for critical review of the manuscript.

The flora of the South Sandwich Islands, with particular reference to the influence of geothermal heating

AbstractAim To carry out as comprehensive a survey as practicable of the flora (higher plants, mosses, liverworts, lichens, basidiomycete fungi and diatoms) of the isolated, volcanically active, South Sandwich Islands archipelago in the southern South Atlantic. To relate the components of this flora to (1) the influence of local geothermal heating and (2) wider regional floras.Location South Sandwich Islands, southern South Atlantic Ocean, maritime Antarctic (56–60° S, 26–28° W).Methods Ice‐free accessible sites on all 11 of the major islands in the archipelago were visited by helicopter in January 1997. During each visit, voucher specimens of each floral group were collected. The comprehensiveness of collections obtained at each site varied with the duration of each visit (a function of tight logistic constraints) and extent of site. Visit duration varied from 1 to 9 h at most sites, with longer periods spent on Bellingshausen Island (2 days) and Leskov Island (1 day). Candlemas Island was examined in greater detail over a 4‐week period in February 1997. At all sites, particular attention was given to areas influenced by geothermal heating.Results Data obtained in 1997 are combined with updated records from the only previous survey (in 1964) to provide a baseline description of the flora of the archipelago, which currently includes 1 phanerogam, 38 mosses, 11 liverworts, 5 basidiomycete fungi, 41 lichenised fungi and 16 diatoms with, additionally, several taxa identified only to genus. Major elements of the moss and liverwort floras are composed of South American taxa (32% and 73%, respectively), with a further 45% of mosses having bipolar or cosmopolitan distributions. These two groups show low levels of Antarctic endemicity (11% and 18%, respectively). In contrast, 52% of lichens and 80% of basidiomycete fungi are endemic to the Antarctic. A further 36% of lichens are bipolar/cosmopolitan, with only 5% of South American origin.Main Conclusions The flora of the South Sandwich Islands is clearly derived from those of other Antarctic zones. The flora of unheated ground is closely related to that of the maritime Antarctic, although with a very limited number of species represented. That of heated ground contains both maritime and sub‐Antarctic elements, confirming the importance of geothermal heating for successful colonisation of the latter group. The occurrence of several maritime Antarctic species only on heated ground confirms the extreme severity of the archipelago’s climate in comparison with well‐studied sites much further south in this biogeographical zone.

Microevolutionary patterns and processes of the Native Hawaiian colonizing fern Odontosoria chinensis (Lindsaeaceae).

The vascular-plant flora of the Hawaiian Islands is characterized by one of the highest rates of species endemism in the world. Among flowering plants, approximately 89% of species are endemic, and among pteridophytes, about 76% are endemic. At the single-island level, however, rates of species endemism vary dramatically between these two groups with 80% of angiosperms and only 6% of pteridophytes being single-island endemics. Thus, in many groups of Hawaiian angiosperms, it is possible to link studies of phylogeny, evolution, and biogeographic history at the interspecific and interisland levels. In contrast, the low level of single-island species endemism among Hawaiian pteridophytes makes similar interspecific and interisland studies nearly impossible. Higher levels of interisland gene flow may account for the different levels of single-island endemism in Hawaiian pteridophytes relative to angiosperms. The primary question we addressed in the present study was: Can we infer microevolutionary patterns and processes among populations within widespread species of Hawaiian pteridophytes wherein gene flow is probably common? To address this broad question, we conducted a population genetic study of the native Hawaiian colonizing species Odontosoria chinensis. Data from allozyme analyses allowed us to infer: (1) significant genetic differentiation among populations from different islands; (2) historical patterns of dispersal between particular pairs of islands; (3) archipelago-level patterns of dispersal and colonization; (4) founder effects among populations on the youngest island of Hawaii; and, (5) that this species primarily reproduces via outcrossing, but may possess a mixed-mating system.

MICROEVOLUTIONARY PATTERNS AND PROCESSES OF THE NATIVE HAWAIIAN COLONIZING FERN ODONTOSORIA CHINENSIS (LINDSAEACEAE)

The vascular-plant flora of the Hawaiian Islands is characterized by one of the highest rates of species endemism in the world. Among flowering plants, approximately 89% of species are endemic, and among pteridophytes, about 76% are endemic. At the single-island level, however, rates of species endemism vary dramatically between these two groups with 80% of angiosperms and only 6% of pteridophytes being single-island endemics. Thus, in many groups of Hawaiian angiosperms, it is possible to link studies of phylogeny, evolution, and biogeographic history at the interspecific and interisland levels. In contrast, the low level of single-island species endemism among Hawaiian pteridophytes makes similar interspecific and interisland studies nearly impossible. Higher levels of interisland gene flow may account for the different levels of single-island endemism in Hawaiian pteridophytes relative to angiosperms. The primary question we addressed in the present study was: Can we infer microevolutionary patterns and processes among populations within widespread species of Hawaiian pteridophytes wherein gene flow is probably common? To address this broad question, we conducted a population genetic study of the native Hawaiian colonizing species Odontosoria chinensis. Data from allozyme analyses allowed us to infer: (1) significant genetic differentiation among populations from different islands; (2) historical patterns of dispersal between particular pairs of islands; (3) archipelago-level patterns of dispersal and colonization; (4) founder effects among populations on the youngest island of Hawaii; and, (5) that this species primarily reproduces via outcrossing, but may possess a mixed-mating system.Corresponding Editor: B. Bowen

Levels of endemism in the Aegean Tenebrionids (Coleoptera, Tenebrionidae)

Biogeographia - vol. XXI - 2000 (Pubblicato il 30 giugno 2000) Biogeografia dell&#39;Anato|ia Levels of endemism in the Aegean Tenebrionids (Coleoptera, Tenebrionidae)1 SIMONE FATTORINI *, PIERO LEO **, LUCA SALVATI *** *Dz&#39;pzzrtz&#39;ment0 di Biologizz Animals 3 de[l’Uom0 (Zoologizz), Universitfz di Roma qLzz Sapimza ’§ Vzkzle dell ’Unz&#39;z1er5it2z, 32 — I-001 85 Rome (Italy) ** Via P. T014, 21 — L09128 Caglizzri (Italy) ***Pz&#39;azzzz F. Morosini, 12 — I—00]36Rome (Italy) Keywords: island biogeography, levels ofendemism, Coleoptera Tenebrionidae, Aegean Islands. SUMMARY This paper is based on the distributions of native tenebrionid species and subspecies on 33 islands in the Aegean Sea. On a total of 166 tenebrionid taxa recorded from the studied islands, 37 (22%) are considered endemic (i.e., taxa restricted to a single island), and 23 (14%) subendemic (i.e., taxa occurring on more than one island but not on the mainland). Percentage of endemic taxa was positively correlated with island area, while percentage ofsubendemic taxa was negatively correlated with area and positively with distance to the mainland. These different patterns could be related to palaeogeographical scenarios. Subendemic taxa probably evolved on islands that, during Pleistocene, were mutually connected forming various island groups presumably at different distances to the mainland, while endemic taxa generally evolved on islands that were completely isolated also in Pleistocene. As a rule, islands that were connected to the mainland during Pleistocene regressions show low levels of endemism, while islands that were never connected to the mainland show generally higher levels of endemism. INTRODUCTION Levels of faunal endemism have been considered in basic researches (e.g., Anderson, 1994) as well as in works concerning biodiversity conservation (e.g., Oosterbroek, 1994). The commonly adopted evaluation of the level of faunal endemism is the percentage of endemic taxa among all taxa recorded Within a given area. However, considerable debate still surrounds the definition of 1 Zoological researches in the Near East by the Universities of Rome: 196. CNR Oceanographic ships on Eastern Mediterranean Islands: 14. This study was supported by grants from MURST 1999 (University of “Roma Tre”) “Variazione geografica e diversit‘a a livello di specie, faune e zoocenosi: cause storiche ed ecologiche”.

The roles of island areaper seand habitat diversity in the species–area relationships of four Lesser Antillean faunal groups

Summary1. We analysed the relationships between species richness, island area, and habitat diversity for birds, bats, butterflies, and reptiles and amphibians on 19 islands in the Lesser Antilles. Habitat diversity was quantified by Simpson's index based on the total areas of five vegetation types on each island. Island area varied over two orders of magnitude (13–1510 km2) and habitat diversity varied between 1 and 3·7 equivalents of equally abundant habitat types.2. Because the Lesser Antilles consist of an inner arc of high, volcanic islands and an outer arc of low‐lying islands formed of uplifted marine sediments, correlations between area and elevation (r2 = 0·32) and between area and habitat diversity (r2 = 0·40) were weak. Habitat diversity was, however, strongly correlated with maximum island elevation (r2 = 0·85).3. Simple correlations of species richness with island area were significant for all four faunal groups, and simple correlations of species richness with elevation and habitat were significant for all groups except bats. In multiple regressions of species richness on area and habitat diversity together, area was a significant effect for birds and bats, and habitat diversity was a significant effect for birds, butterflies, and reptiles and amphibians.4. These results suggest that the four Lesser Antillean taxonomic groups differ in their responses to area and habitat diversity. For butterflies and for reptiles and amphibians, the relationship of species richness to area is probably a fortuitous consequence of a relationship between habitat diversity and area. Bird species richness responds independently to both habitat diversity and area, and bat species richness is influenced by area but not by habitat diversity.5. We suggest that this variation is related to differences in several biological traits of the different faunal groups. Strong habitat‐diversity effects are likely in taxa with high degrees of habitat specialization, populations large enough to have a low probability of stochastic extinction, life‐cycles that include a resistant resting stage that reduces vulnerability to catastrophic extinction, or a combination of these traits. In contrast, strong area effects are likely in taxa with weak habitat specialization, low population density, or both.6. At least in Lesser Antillean birds, it is unlikely that immigration depends on island size. Therefore, the species–area relationship for birds is probably generated by island‐size‐dependent extinction. Among the four taxonomic groups we studied, only butterflies are likely to show a ‘rescue effect’ stemming from frequent between‐island movement of individuals, as only butterflies exhibited low levels of endemism and lacked a unique area effect for species richness.7. Considered in concert, these taxon‐specific differences demonstrate that both biological characteristics of organisms and geographical features of island groups mediate the relative contribution of island area and habitat diversity to variation in species richness.