Lesser Antillean Island Research Articles

Anoles of St. Vincent (Squamata: Polychrotidae): Population Densities and Structural Habitat Use

We examined population densities and structural microhabitat use by Anolis griseus and A. trinitatis at eight sites on the leeward (western) coast of St. Vincent, West Indies. Estimates of population density based on the Schnabel method varied according to habitat complexity and ranged to 5,208/ha for A. griseus (a higher estimate at one site was not considered due to conditions that compromised the accuracy of estimates) and to 27,923/ha for A. trinitatis. Our highest estimate for both species at one site (32,867/ha) was the highest yet recorded for any site on a two-species Lesser Antillean island. For both species, larger individuals tended to perch higher and on perches of larger diameter than smaller lizards, with adult male A. griseus using the highest and largest diameter perches. However, considerable overlap in perch use among other size classes of A. griseus and all size classes of A. trinitatis suggests that structural habitat partitioning is not rigid in these two species. Although A. griseus was most abundant at densely shaded sites, A. trinitatis was essentially ubiquitous, supporting the predictions that these anoles were ecologically versatile and abundance and microhabitat use would reflect available vegetative structure.

Impacts of a volcanic eruption on the forest bird community of Montserrat, Lesser Antilles

Volcanic eruptions are an important and natural source of catastrophic disturbance to ecological communities. However, opportunities to study them are relatively rare. Here we report on the effects of the eruption of the Soufrière Hills volcano on the forest bird community of the Lesser Antillean island of Montserrat. The island's species‐poor avifauna includes 11 restricted‐range species, including the Critically Endangered endemic Montserrat Oriole Icterus oberi. Analysis of monitoring data from 1997 to 2005 indicates that counts of most species were substantially lower following major ashfalls. However, this effect was short‐lived, with rapid population recovery in subsequent years. Furthermore, levels of seasonal rainfall appear to have been at least as important in determining population trends as ashfall. Overall, most species were at least as abundant at the end of the study as at the start, and no forest bird species have been extirpated from Montserrat. We discuss potential ecological drivers of ashfall impacts on populations: there is some evidence that terrestrial foragers were most severely affected.

A report on the status of the herpetofauna of the Commonwealth of Dominica, West Indies

We review the status of the herpetofauna of the Commonwealth of Dominica, which is often cited as having the most complete extant herpetofauna of all the Lesser Antillean islands, a region which has suffered much historical extinction. Recent years have seen a number of threats of grave concern to island and regional endemic species, the chief of these being the arrival of chytridiomycosis on this island with negative effects on the mountain chicken Leptodactylus fallax, and the establishment of a non-native Greater Antillean anole, Anolis cristatellus, which has succeeded in displacing the native endemic Anolis oculatus from a part of the island in less than a decade.

Herpetofaunal communities of the leeward slopes and coasts of St. Vincent: A comparison of sites variously altered by human activity

Like other Lesser Antillean islands, human-modified habitats are prevalent on much of St. Vincent, especially in coastal regions. Eighteen terrestrial species of reptiles and amphibians are known to occur on the island. Some species demonstrate considerable versatility, and are found in both altered and relatively natural habitats. Others, however, are restricted to one extreme or the other. To better understand the composition of herpetofaunal communities, we surveyed seven sites on the leeward side of the island, chosen to represent different degrees of human alteration. We found the highest diversity index in an urban area, where introduced species prevailed. Endemic species were more abundant in more natural sites. Three species, Eleutherodactylus johnstonei, Anolis griseus, and A. trinitatis, were at all sites.

The St. Vincent (Lesser Antilles) herpetofauna: Conservation concerns

The Lesser Antillean island of St. Vincent harbors 18 species of terrestrial amphibians and reptiles: four frogs (including the endemic Pristimantis shrevei ), one turtle, ten lizards (including endemic Anolis griseus and A. trinitatis ), and three snakes (including endemic Corallus cookii and Chironius vincenti ). In addition, four species of marine turtles are known from the region. Ecological relationships of an introduced frog ( E. johnstonei ) and an introduced lizard ( A. sagrei ) should be monitored in order to evaluate any potentially negative impact on endemic congeners. Two endangered endemic species ( P. shrevei and C. vincenti ) may benefit from sympatry with the endemic parrot, Amazona guildingii , the national bird of St. Vincent, with which they share high-quality upland forest habitat. Like other West Indian herpetofaunas, that on St. Vincent faces threats that include dramatic habitat alterations, introduced predators (mongooses, domestic cats) and competitors (e.g., A. sagrei ), changes in the prey base, and the potential introduction of the chytrid fungus. These threats can best be addressed by development and implementation of effective management programs based on ecological studies by local and foreign biologists.

Economic Significance of Tourism in The Lesser Antilles

Abstract The objective of the article is an attempt to assess the economic significance of tourism in chosen islands of the Lesser Antilles. Diversification of the significance of tourism in economy between particular islands of the Lesser Antilles is very extensive. The economy of islands such as the British Virgin Islands, Anguilla, Antigua and Barbuda is highly dependent on tourism. On the other hand, islands such as Martinique and Curaçao derive small profits from tourism. The tourism satellite account method was used to show to what a degree each of the Lesser Antilles islands is dependent on tourism and what profits are derived from it. The account considers both direct and indirect outlays on tourism. The selected countries are divided into groups according to the intensity of tourism, the size of the GDP generated per one inhabitant as well as the share of employment in tourism per total employment. A group of countries and dependent territories deriving greater and lesser economic benefits from tourism than might appear from the intensity of tourism is identified.

Effect of species interactions on landscape abundance patterns

SummaryWe develop a process‐based bioenergetic model that incorporates population dynamics to predict the abundance trends for Anolis lizards along elevation gradients in the Lesser Antilles islands. Model outcomes are compared with empirical abundance trends on islands with and without species interactions and with differential topography.The bioenergetic model incorporating body size, thermal physiology and prey abundance qualitatively predicts how lizard abundance declines with elevation for solitary anole species. Empirical elevation trends on northern and southern one‐species islands have similar slopes but different intercepts at sea level. The greater anole abundance on the southern islands is predicted by the model when parameterized with the empirically observed higher insect abundance.Anole abundance patterns on two‐species islands diverge from the bioenergetic model predictions. One species is more abundant at sea level and the other more abundant at higher elevations compared with the trend for solitary anoles. Species interactions modify population responses to elevation gradients.

Lizard habitat partitioning on islands: the interaction of local and landscape scales

AbstractAim This study addresses how species resolve environmental differences into biological habitats at multiple, interacting spatial scales. How do patterns of local habitat use change along an elevation gradient? How do patterns of local habitat partitioning interact with partitioning at a landscape scale?Location Northern and southern Lesser Antilles islands, West Indies.Methods We document howAnolisDaudin, 1802 lizards partition habitat locally at sites along a landscape‐scale elevation gradient. We examine habitat partitioning both with and without interspecific interactions in the predominately flat northern Lesser Antilles islands and in the more mountainous southern islands.Results Anoles partition local habitat along perch‐height and microclimate axes. Northern‐group sympatric anoles partition local habitat by perch height and have overlapping distributions at the landscape scale. Southern‐group sympatric anoles partition local habitat by microclimate and specialize in particular habitats at the landscape scale. In both the northern and southern groups, species use different perch heights and microclimates only in areas of species overlap along the elevation gradient.Main conclusions We demonstrate the interaction between local‐ and landscape‐scale habitat partitioning. In the case of microclimate partitioning, the interaction results from the use of thermal physiology to partition habitat at multiple scales. This interaction prompts the question of whether habitat partitioning developed ‘local‐out’ or ‘landscape‐in’. We pose this dichotomy and present a framework for its resolution.

Two new species of Charianthus (Melastomataceae: Miconieae) from the Lesser Antilles

In the course of a phylogenetic analysis and systematic revision ofCharianthus, it was discovered thatC. purpureus, as traditionally circumscribed, is polyphyletic, consisting of three morphologically diagnosable entities. Thus two new species,Charianthus dominicensis andC. grenadensis, are described and illustrated. Each is endemic to the Lesser Antillean island for which it is named—Dominica and Grenada, respectively.Charianthus, the only vascular plant genus endemic to the Lesser Antilles, comprises six species of nectariferous, hummingbird-pollinated shrubs and small trees.

Bats of Nevis, Northern Lesser Antilles

Only one species of bat, Molossus molossus, previously has been documented as occurring on the northern Lesser Antillean island of Nevis. Field research and reviews of existing museum collections have provided documentation based on voucher specimens for an additional seven species occurring on the island — Noctilio leporinus, Brachyphylla cavernarum, Monophyllus plethodon, Ardops nichollsi, Artibeus jamaicensis, Natalus stramineus, and Tadarida brasiliensis. The biological diversity of the chiropteran fauna on Nevis is similar to that found on other islands in the northern Lesser Antilles. Ecologically, this is a simple chiropteran fauna, including one piscivore (N. leporinus), one omnivore (B. cavernarum), one pollenivore/nectivore (M. plethodon), two frugivores (A. nichollsi, A. jamaicensis), and three insectivorous species (N. stramineus, T. brasiliensis, M. molossus). Species-area and species-elevation analyses for the chiropteran fauna of the Greater and Lesser Antillean islands gave r 2 values of 0.74 and 0.33, respectively. In the species-area analysis the bat fauna of Nevis falls above the regression line and in the species-elevation analysis it falls almost on the line. The chiropteran fauna of Nevis lies outside the Lesser Antillean Faunal Core and would be best characterized as a generalized Lesser Antillean fauna that appears to be characteristic of the northern Lesser Antilles.

An annotated list of Orthoptera from St Eustatius and Saba, Dutch West Indies, with descriptions of two new cricket species (Trigonidiidae, Mogoplistidae)

Abstract Orthopteran species on the Lesser Antilles islands of St Eustatius and Saba are poorly known. Recent field surveys and examinations of museum collections revealed 24 species separated into the following families: Acrididae, 6; Tettigoniidae, 6; Gryllidae, 2; Mogoplistidae, 1; Oecanthidae, 1; Phalangopsidae, 2; Podoscirtidae, 5; Trigonidiidae, 1. Seven species are new, 2 of which are described herein (Mogoplistidae: Cycloptilum eustatiensis; Trigonidiidae: Cyrtoxipha orientalis). Crickets alone are represented by 12 species. Among all species, 1 is cosmopolitan, 2 are neotropical, 4 are distributed in most of the Caribbean region, 5 occur in one or several provinces located in the Greater Antilles, and 12 are distributed in the Lesser Antilles province only. Among these last species, 8 could be endemic to St Eustatius and/or Saba. Species diversity and distribution patterns are discussed in relation to island habitats and groupings.

Rapid decline of the volcanically threatened Montserrat oriole

Prior to 1995, the Montserrat oriole ( Icterus oberi) was confined to ca. 30 km 2 of hill forest on the Lesser Antillean island of Montserrat, but was not listed as globally threatened. Since then, the eruption of the Soufriere Hills volcano has destroyed more than half of the species’ range. Recent intensive monitoring has indicated that the species has also declined dramatically within the remaining intact forest, and is now critically threatened. Different monitoring and analytical methods indicate a decline of 8–52% p.a., and a remaining global population of ca. 100–400 pairs. This case study justifies the use of the restricted range criterion in designating threatened species. Despite intensive monitoring and the use of several analytical methods, it has proved surprisingly difficult to estimate the magnitude of the oriole’s decrease, or to control for potential artefacts in the census method. We discuss the reasons for this. The cause(s) of population decline in the intact forest are unclear, though two hypotheses appear plausible: a decrease in arthropod food, a result of volcanic ash fall, and an increase in nest predation as a result of increases in populations of opportunistic omnivores.

Adaptive radiation versus intraspecific differentiation: morphological variation in Caribbean Anolis lizards

Abstract Lizards in the genus Anolis have experienced adaptive radiation in the Greater Antilles, producing a suite of species morphologically adapted to use different parts of the environment. In the Lesser Antilles, adaptive radiation has not occurred, but on some islands, interpopulational variation is high and represents adaptation to different habitats. We compared the extent of morphological differentiation among Greater Antillean habitat specialists with that exhibited among populations of two species, Anolis marmoratus and A. oculatus, from the Lesser Antillean islands of Guadeloupe and Dominica. Although extensive, intraspecific divergence in the Lesser Antilles is substantially less in magnitude than the differences among habitat specialists in the Greater Antilles. All populations of A. marmoratus are most similar to Greater Antillean trunk-crown habitat specialists, but populations of A. oculatus differ in their affinities: some are similar to trunk-crown anoles, but others are more similar to trunk-ground habitat specialists.

Slicer Laser Altimetry In The Eastern Caribbean

Data acquired by the airborne Scanning Lidar Imager of Canopies by EchoRecovery (SLICER) laser altimeter provided high-resolution digital topographicdata over Puerto Rico, the Dominican Republic and several of the Lesser AntillesIslands. The instrument was developed by the NASA-Goddard Space Flight Center.It has the capability of multibeam resolution of ground elevations beneath densecanopy areas. Data, therefore, can be used to generate a more accurate representation of the ground surface by removing the vegetation cover. Although internal precision is high (10 cm to 1 m), absolute accuracy is difficult to evaluate and depends on several factors, including the post-processed kinematic GPS (KGPS) flight path for the aircraft platform and clear identification of ground returns in the SLICER waveform. We compared topographic profiles from USGS 30 m and 1:250K DEMs for Puerto Rico with those generated by SLICER and with spot elevations derived from static and continuous GPS surveys. SLICER and KGPS surveys cross at six points in western Puerto Rico. Agreement between both elevation data sets is excellent and well fit (r = 0.921) by a linear model with a final residual bias of -0.501 m for SLICER ground returns relative to KGPS elevations. The agreement between SLICER and USGS 30 m DEMs is also very good with the largest errors associated with steep slopes and high vegetation cover. Residuals between KGPS and USGS 30 m DEMs are +1 ± 25 m, assuming a fixed uniform offset of +43.23 m between WGS84 and mean sea level.

A Taxonomic Revision of the Genus Agave (Agavaceae) in the Lesser Antilles, with an Ethnobotanical Hypothesis

The genusAgave (Agavaceae) is revised taxonomically for the Lesser Antilles. All 12 previously recognized species are placed into synonymy underAgave karatto Miller. A neotype is selected for the nameAgave karatto, and lectotypes are designated forA. barbadensis Trel.,A. medioxima Trel.,A. obducta Trel.,A. vangrolae Trel., andA. ventum-versa Trel. Specimens are cited for most of the Lesser Antillean islands. That the Caribbean agaves are similar to the MexicanAgave nayaritensis Gentry is supported. The hypothesis that the pattern of partial sterility, clonality, and minimal morphological differentiation of the Lesser Antillean agaves is related to prehistoric human activity is developed based on similar patterns among mainland agaves and historical information. Uses for the archaeological “Barbados shell tool” may have included decorticating agave leaves for fiber extraction.

Cuphophyllus pegleri sp. nov. (Hygrophoraceae) from the Lesser Antilles

In 1983, Pegler described collections from the Lesser Antillean islands of Martinique and Dominica of what were thought at the time to be Camarophyllus niveicolor (Murrill) Singer. Pegler (1983) noted that collections from the Lesser Antilles had a distinct odour of mint, but that Murrill (1911) made no mention of odour in his original description of this species from Mexico. Although C. niveicolor is not easily distinguished from related species in the field, it has very large spores that easily separate it microscopically from other white species of Cuphophyllus sect. Virginei (Bat.) Singer. During the British Mycological Society expedition to Cuyabeno in Amazonian Ecuador in 1993, Thomas Laessoe collected specimens of Cuphophyllus in sect. Virginei that closely resembled the type collection of C. niveicolor both macroscopically and microscopically. The Ecuadorian collection was completely odourless, which suggested that the collections which Pegler described from the Lesser Antilles might be an undescribed species and not C. niveicolor. Subsequent comparisons of the relevant collections revealed that the Lesser Antillean specimens differed from C. niveicolor in several microscopic features and the mint odour. This distinctive species is formally described and illustrated below in honour of David Pegler's mycological work in the Lesser Antilles and on the Hygrophoraceae of Puerto Rico.

THE PARADOX OF THE PHYLOGENY: CHARACTER DISPLACEMENT OF ANALYSES OF BODY SIZE IN ISLAND ANOLIS.

The evolution of body size in Anolis lizards of the Lesser Antilles Islands has been the subject of intensive, if divisive, study. Early research by Schoener revealed a regularity in the number of Anolis species that coexisted on islands and the difference in body size between coexisting congeners in the Northern Lesser Antilles. This consistent pattern of body size was suggested to be the result of competitive character displacement. Two recent studies critically evaluated this hypothesis by incorporating information about the phylogenetic relationships of insular Anolis. Roughgarden and Pacala suggested that the patterns of body-size differences in the Northern Lesser Antilles could be explained as a cyclical phenomenon that they labeled a taxon cycle. However, Losos supported the character-displacement hypothesis ("size adjustment"). The conflict between these two studies is important because both investigations were based on the same phylogenetic hypothesis. We investigated body-size evolution in Lesser Antilles Anolis to resolve the differences in the conclusions of these studies. Our new analysis supported the taxon-cycle hypothesis but nevertheless failed to reject the character-displacement hypothesis. We argue that this curious scenario is largely a function of the method by which phylogenetic information is incorporated in comparative analyses. Different comparative analyses may lead to dramatic differences in results and ambiguity in the conclusions to be drawn. We suggest that ecologists and evolutionary biologists specifically consider the underlying assumptions and models of character evolution inherent to each of the phylogenetically based analytical methods now available.

Parallels between island lizards suggests selection on mitochondrial DNA and morphology

Parallels between species on historically independent islands have been shown to be a powerful means of testing for the action of natural selection on morphology. Mitochondrial DNA evolution is often assumed to be selectively neutral, but this is difficult to test empirically. Here we show that parallels are present between two species of lizards on the geologically distinct but ecologically similar Lesser Antillean islands of Dominica and Basse Terre (Guadeloupe). These parallels are found not only in morphological variation but also in mitochondrial DNA variation and these are correlated with similar ecological gradients. A morphological cline in Anolis oculatus along the Caribbean coast of Dominica is compared to sequence variation in the cytochrome b gene, which shows exceptionally high variability. Patterns of sequence variation and morphology (especially scalation) are congruent, and are significantly correlated with moisture gradients. Anolis marmoratus on the adjacent island of Basse Terre (Guadeloupe) shows parallel patterns of morphological and cytochrome b variation along the Caribbean coast, and these are also significantly correlated with moisture gradients.

The politics of forced Indian labour in La Española 1493–1520

When Christopher Columbus arrived at La Espanola (the large island called in English Hispaniola, now divided between the modern states of Haiti and the Dominican Republic) in early December 1492, he encountered a society entirely different from the ones described by Marco Polo for Asia and India. Columbus, sailing through the Bahamas and Cuba, had already discovered indios who went about naked, did not know the wheel nor used any metal tools, practised agriculture and fishing, and had a complex social structure and an elaborated system of religious beliefs. These ‘Indians’ called themselves Tainos, to signify that they were peaceful, although they defended themselves well from their neighbouring enemies, the Caribes of the Lesser Antilles islands (Colon 1961; Las Casas 1967)

Development of a prehistoric interaction sphere in the northern Lesser Antilles

[First paragraph]INTRODUCTION This paper identifies the development of a prehistoric interaction sphere among a specific cluster of northern Lesser Antillean islands, by examining physicalgeography, natural resources and archaeological remains. The islands used for this study are Anguilla, St. Martin-St. Maarten (hereafter to be referred to simply as St. Martin), Dog Island, St. Barthelemew (St. Baits) and their adjacent cays. It is suggested that the processes of divergent evolution and adaptive radiation increased the isolation of economic exploitation and social adaptations, thus allowing for the emergence of a cluster specific interaction sphere.