Leaf Litter Frogs Research Articles

The matrix-tolerance hypothesis: an empirical test with frogs in the Atlantic Forest

The matrix-tolerance hypothesis suggests that the most abundant species in the inter-habitat matrix would be less vulnerable to their habitat fragmentation. This model was tested with leaf-litter frogs in the Atlantic Forest where the fragmentation process is older and more severe than in the Amazon, where the model was first developed. Frog abundance data from the agricultural matrix, forest fragments and continuous forest localities were used. We found an expected negative correlation between the abundance of frogs in the matrix and their vulnerability to fragmentation, however, results varied with fragment size and species traits. Smaller fragments exhibited stronger matrix-vulnerability correlation than intermediate fragments, while no significant relation was observed for large fragments. Moreover, some species that avoid the matrix were not sensitive to a decrease in the patch size, and the opposite was also true, indicating significant differences with that expected from the model. Most of the species that use the matrix were forest species with aquatic larvae development, but those species do not necessarily respond to fragmentation or fragment size, and thus affect more intensively the strengthen of the expected relationship. Therefore, the main relationship expected by the matrix-tolerance hypothesis was observed in the Atlantic Forest; however we noted that the prediction of this hypothesis can be substantially affected by the size of the fragments, and by species traits. We propose that matrix-tolerance model should be broadened to become a more effective model, including other patch characteristics, particularly fragment size, and individual species traits (e.g., reproductive mode and habitat preference).

Molecules meet macroecology—combining Species Distribution Models and phylogeographic studies

Combination of various techniques allows the identification of unique genetic lineages and/or taxa new to science via integrative taxonomy approaches. Next to molecular methods such as DNA ‘barcoding’ and phylogeographic analyses, Species Distribution Models may serve as compliment techniques allowing spatially explicit predictions of a species’ potential distribution even across millennia. They may facilitate the identification of possible recent and historical gene flow pathways. Herein, we highlight advantages of the combination of both molecular and macroecological approaches using the African miniature leaf litter frog Arthroleptis xenodactyloides as example.

Small, specialised and highly mobile? The tree-hole breeding frog, Phrynobatrachus guineensis, lacks fine-scale population structure

Data on population dynamics and distribution are of primary interest to biologists because they reveal information about the species' ecology and evolution and are thus essential for conservation efforts. Patchily distributed species are especially interesting for conservation studies, because of their sometimes very specific environmental requirements. An example of a highly specialised species is the leaf litter frog Phrynobatrachus guineensis. This small species (<20 mm) is short lived, presumably weakly mobile and highly specialised because it uses tree-holes and other small water-filled cavities with very particular abiotic and biotic characteristics for breeding. Previous field studies revealed that P. guineensis exhibited a clumped distribution in Taï National Park (TNP), Ivory Coast, suggesting that the park's population might be subdivided into several (sub)populations. We therefore investigated the population genetic structure of the park using four microsatellite loci, which are the first described microsatellite markers for any African anuran in general and for a species of the family Phrynobatrachidae in particular. In contrast to our expectations, we detected only a slightly significant genetic differentiation based on allele frequencies. We found no correlation between the geographic and genetic distances (isolation by distance) and Bayesian clustering revealed no genetic substructure. We did, however, detect small but significant genetic differentiation between subsequent seasons. The most probable explanation for the lack of population structure is that P. guineensis is more mobile than expected. Adults, most likely females but possibly also juveniles, are able to traverse matrix habitats in which no breeding activities were detected. The temporal genetic differentiation may be the consequence of genetic drift due to high mortality rates and/or non-random mating. Both explanations would be consistent with our field data.

Ecology of Ischnocnema parva (Anura: Brachycephalidae) at the Atlantic Rainforest of Serra da Concórdia, state of Rio de Janeiro, Brazil

Ischnocnema (Brachycephalidae) includes many species that are important members of the leaf litter frog communities in the Atlantic Rainforest of Brazil. Ischnocnema parva (Girard, 1853) is endemic to the Atlantic Rainforest biome and is restricted to the forests of southeastern Brazil. Currently, the available information about the ecology of I. parva is scarce. We studied the diet, the habitat use, reproduction and density of I. parva in an area of Atlantic Rainforest at the Concórdia mountain range, Rio de Janeiro. Individuals of I. parva were captured in April 2005 using different sampling methods: time constrained search (transects), plots of 5 x 5 m (25 m²) on the litter, and pitfall traps with drift fences. We found 240 frogs; 35 females and 205 males. Females (mean SVL = 19.1 mm) were significantly larger (F1,238 = 143.016, R² = 0.375, p < 0.001) than males (13.2 mm). The species preyed mainly on arthropods, with ants and isopods being the most important items, both showing high values of importance index (Ix = 50.0 and 26.7, respectively). Ischnocnema parva is a terrestrial species whose preferential microhabitat at the Serra da Concórdia was the litter of the forest floor (78.7%). The activity was predominantly crepuscular-nocturnal and the estimated density of I. parva was 24.9 ind/100 m². For the eight ovigerous females captured, the mean number of mature oocytes per female was 25 (range: 22-30) and the oocyte mean diameter was 1.11 mm (N = 40 oocytes). Oocyte number increased with female body size (R² = 0.504, F1,6 = 6.107, p < 0.05, N = 8), indicating that as females increase in size they produce larger clutches. Some ecological aspects such as diet and microhabitat use were similar to that observed for an insular population of I. parva, whereas reproductive traits differed. Thus, long term studies are necessary to understand the extent to which these differences are explained by environmental factors.

Calcified Integumentary Structures in Anurans

Although often overlooked, the integument of many vertebrates is reinforced by skeletal elements. In anurans these calcified structures include osteoderms, bone‐rich elements, and the lamina calcarea, a calcified, acellular layer that lacks collagen. We investigated the histology of anuran integument with a special focus on taxa developing skeletal elements. When present, the lamina calcarea forms a thin but discrete horizon at the interface between the superficial and deep dermis. This layer is rich in glycosaminoglycans (GAG) and is structurally unlike bone and cartilage. In contrast, anuran osteoderms are composed of cellular bone with limited GAG. A partial ontogenetic series of the tree frog Phyllomedusa bicolor provides the first details of anuran osteoderms development. In P. bicolor osteoderm development begins as a cluster of small calcified centres localized over the head. With continued body growth, osteoderms become larger in size and become distributed across the dorsal and ventral surfaces of the body, and across the limbs. The leaf litter frog Brachytarsophyrys cariensis is unusual in developing both osteoderms (on the dorsal body surface) and a lamina calcarea (on the ventral body surface). Our data shows that anuran integument has the ability to form skeletal elements and suggests that these elements arose in multiple anuran lineages.Grant Funding Source: NSERC

Seasonality, age structure and reproduction of Leptodactylus (Lithodytes) lineatus (Anura, Leptodactylidae) in Rondônia state, southwestern Amazon, Brazil

Leptodactylus(Lithodytes) lineatus (Schneider, 1799) is an Amazonian leaf litter frog considered rare or uncommon in several studies on anuran communities. Despite being a widely distributed frog in Amazonian forests, knowledge of the biology and ecology of this species is relatively scarce. This species has been reported to live in association with leaf-cutter ant nests (Atta spp.) during the breeding period. In this paper we present data on the seasonality of this species and some reproductive information gathered at a locality of Rondônia state, northwestern Brazil. Field work was carried out between April 2001 and March 2002, with the use of pitfall traps with drift fences as a survey method. Leptodactylus (L.) lineatus had a higher capture frequency in this locality compared to that of other studies carried out in other Amazonian localities, possibly because this species has secretive habits, such as calling and breeding from nests of leaf-cutting ants, and are difficult to find during visual encounter surveys. The breeding period occurs between October and March. Calling males and egg-bearing females were found between September and February and juvenile recruitment occurred mainly from the end of the rainy season to the beginning of the dry season (February to June). Males and females show sexual dimorphism in SVL, females being significantly larger than males. The number of ovarian eggs per female varies from 110 to 328 and analyses indicate that there is a significant correlation with SVL.

Dispersal to or from an African biodiversity hotspot?

Biodiversity hotspots are centres of endemism and thus contain many range-restricted species. In addition, within these hotspots occur widespread species that might have originated within a hotspot before dispersing to neighbouring or distant regions. We test this hypothesis with a phylogeographic analysis of a miniature leaf litter frog, Arthroleptis xenodactyloides, that has a large distribution throughout the Eastern Arc biodiversity hotspot and other regions in East Africa. Maximum-likelihood and Bayesian estimates of the mitochondrial gene phylogeny are used as a proxy for understanding the evolutionary history of diversification and the historical relationships between populations. The north-south range of this species extends for approximately 1900 km; our sampling covers approximately 85% of this range. Using phylogenetic comparative methods, we estimate the region of origin and direction of dispersal within A. xenodactyloides. We compare contrasting hypotheses of latitudinal range expansion using bayes factors. The ancestral region of origin of A. xenodactyloides is reconstructed as having occurred within the Eastern Arc before dispersing southwards into the southern Rift Mountains, probably in the Pleistocene. The phylogeographic structure within this leaf litter frog is surprisingly similar to that of forest birds, revealing that similar geographic features might have had a driving role in diversification of these very dissimilar taxa. Latitudinal expansion occurred early in the evolutionary history of A. xenodactyloides, which may indicate that physiological adaptation facilitated its wide geographic distribution.

Towards an ecologically-sustainable forestry in the Atlantic Forest

Since pristine Atlantic Forest remnants are vanishing, and biological reserves are in short, conservation of biodiversity will largely depend on proper management of the anthropogenic matrix. Here, we test (1) the effectiveness of ecologically-managed tree monocultures in maintaining Araucaria Forest biodiversity, (2) how this effectiveness change among taxa, and (3) we discuss management principles that can be used by the forestry industry in order to contribute positively to biodiversity conservation. The study was conducted in the São Francisco de Paula National Forest, southern Brazil, an environmental mosaic composed mostly of patches of Araucaria Forest and ecologically-managed monocultures of Araucaria, Pinus and Eucalyptus. Using standardized sampling methods in these four main habitats, we have recorded the richness and species composition of small mammals, birds, leaf-litter frogs, butterflies, galling insects, spiders, opiliones, flatworms, woody plants, epiphytic angiosperms, epiphytic ferns, lichens, and fruit-body producing fungi. Overall, we recorded 506 species in Araucaria Forest, 181 (36%) of which were exclusive of this habitat while 325 (64%) could be found in at least one monoculture. Distribution patterns of species richness and number of records across taxonomic groups showed that a large biodiversity can be found inside ecologically-managed plantations of Araucaria, Pinus, and Eucalyptus. For all studied taxa, except for epiphytic angiosperms and fruit-body producing fungi, more than half of the Araucaria Forest species could be found living on monocultures. We discuss how the actual management practices of the forest industry can be improved to contribute positively to the conservation of the Atlantic Forest biodiversity.

Density and richness of leaf litter frogs (Amphibia: Anura) of an Atlantic Rainforest area in the Serra dos Órgãos, Rio de Janeiro State, Brazil

Data on species composition, richness, and density are presented for the leaf litter frog assemblage of an area of Atlantic Rainforest at the Serra dos Órgãos mountain range, in the state of Rio de Janeiro, southeastern Brazil. Three sampling methods were used: plot sampling, visual encounter surveys, and pitfall traps. The local assemblage of leaf litter frogs was composed of 16 species, with the direct-developing species, Euparkerella brasiliensis (Parker, 1926), being the most abundant. The estimated density of the local leaf litter frog assemblage based on plot sampling was 17.1 ind/100 m² and the estimated overall leaf litter frog mass was 684.2 g/ha. The estimated density of leaf litter frogs at the present study is the highest currently reported for Atlantic Rainforest areas, which reinforces the idea of higher densities of leaf litter frogs in the Neotropical Region compared to the Old World tropics.

Three new species of leaflitter frogs from the upper Amazon forests: cryptic diversity within Pristimantis " ockendeni " (Anura: Strabomantidae) in Ecuador

Three new species of leaflitter frogs from the upper Amazon forests: cryptic diversity within Pristimantis " ockendeni " (Anura: Strabomantidae) in Ecuador

Impacto do desmatamento e formação de pastagens sobre a anurofauna de serapilheira em Rondônia

A riqueza e a diversidade de anfíbios anuros de serapilheira em áreas de floresta e de pastagem foram estudadas em Rondônia. A eficiência da utilização de armadilhas de interceptação e queda foi analisada. As armadilhas foram instaladas em três ambientes distintos: interior de floresta, distante de ambientes aquáticos permanentes; interior de floresta, a cerca de 100 metros de rio; área de pastagem, distante de ambientes aquáticos permanentes. Foram capturados 1.324 espécimes pertencentes a 27 espécies, distribuídas em nove famílias: Aromobatidae (1 espécie), Brachycephalidae (2), Bufonidae (4), Cycloramphidae (1), Dendrobatidae (1), Hylidae (5), Leiuperidae (1), Leptodactylidae (7) e Microhylidae (5). O emprego de armadilhas de interceptação e queda permitiu registrar 57% das espécies conhecidas para essa localidade, sendo particularmente eficiente para a captura de anuros de hábitos terrícolas e fossoriais. Foram capturados menos indivíduos nos três meses mais secos e houve maior diversidade durante a estação chuvosa. Maior riqueza e diversidade foram registradas nos ambientes florestados, em relação à pastagem, observando-se decréscimo de espécies com o desmatamento. A conversão da floresta em pastagens ocasiona modificações no ambiente (diminuição de locais para reprodução, diminuição da disponibilidade de alimento, perda da serapilheira, compactação do solo, alterações microclimáticas, aumento da abundância de espécies de áreas abertas, etc.) criando condições desfavoráveis para a sobrevivência de algumas espécies.

Human Disturbance Influences Behaviour and Local Density of Juvenile Frogs

AbstractHabitat can be rendered less suitable because of numerous factors, including the presence of humans. Human disturbance is implicated as a threat for hundreds of amphibian species, but there is a dearth of peer‐reviewed literature addressing this topic, and what little is available focuses on adults. Here we present the results of a study examining the effects human disturbance may have on the distribution and behaviour of juvenile Eastern African leaf litter frogs of the genus Arthroleptis. Our findings show that human activity affects the local density of juveniles and strongly influences escape behaviour. These results indicate that costs of human disturbance to juvenile frogs may be severe and that human disturbance may play a role in fragmenting local frog populations.

Are leaf-litter frogs and lizards affected by edge effects due to forest fragmentation in Brazilian Atlantic forest?

Edge effects encompass biotic and abiotic changes resulting from the interaction between two different habitat types (Murcia 1995). Edge habitats are ecologically distinct from patch interiors, and understanding how ecological patterns change near edges is important in understanding landscape-level dynamics such as the impacts of fragmentation (Rieset al. 2004). Abiotic conditions at the forest edge, such as increased wind and solar radiation, increased fluctuations in temperature, and decreased humidity, may affect forest-adapted organisms (Harperet al. 2005, Murcia 1995). So, edges may affect lizards and amphibians due to their physiological needs (Lehtinenet al. 2003, Vallan 2000). Anurans are considered sensitive to environmental changes due to their permeable skin, shell-less eggs and use of land as well as freshwater habitats (Vallan 2000). Changes in vegetation structure and microclimate are likely to be the predominant factor affecting amphibian abundances across edges (Jellineket al. 2004, Marsh &amp;amp; Pearman 1997, Schaepfer &amp;amp; Gavin 2001, Urbina-Cardonaet al. 2006).

Three new species of leaflitter frogs from the upper Amazon forests: cryptic diversity within Pristimantis "ockendeni" (Anura: Strabomantidae) in Ecuador

We describe three new species of Pristimantis leaflitter frogs from the upper Amazon basin of Ecuador: Pristimantis achuar, Pristimantis altamnis, and Pristimantis kichwarum. Each of these new species was previously considered to be part of a single species, formerly known as Eleutherodactylus ockendeni (Boulenger) morph B. However, analysis of DNA sequences together with examination of the morphology of more than 600 specimens from Ecuador reveals that multiple species were confused under the same name. The morphological differences among the three new species are subtle but consistent: presence or absence of a black canthal stripe and/or supratympanic ridge, snout-vent length, and ventral colouration. The three species are generally allopatric and geographically restricted, although at some localities two of the species occur sympatrically.Describimos tres especies nuevas de ranas del sotobosque de la cuenca Amazónica Ecuatoriana: Pristimantis achuar, Pristimantis altamnis y Pristimantis kichwarum. Estas especies fueron consideradas antes como una sola especie bajo el nombre Eleutherodactylus ockendeni (Boulenger) morfo B. Sin embargo, el análisis de secuencias de ADN y la examinación de la morfología de más que 600 especímenes Ecuatorianos indican que en realidad existen tres especies. Sus diferencias morfológicas son sutiles pero constantes: presencia o ausencia de una raya cantal negra y/o de un pliegue supratimpánico y su coloración ventral. Las tres especies tienen distribuciones alopátricas y distintas aunque en algunas localidades se puede encontrar dos de las tres especies juntas.

Effects of Forest Fragmentation and Habitat Degradation on West African Leaf‐Litter Frogs

Habitat degradation alters the dynamics and composition of anuran assemblages in tropical forests. The effects of forest fragmentation on the composition of anuran assemblages are so far poorly known. We studied the joint influence of forest fragmentation and degradation on leaf-litter frogs. We specifically asked whether the processes structuring leaf-litter anuran assemblages in fragmented forests are the same as those in continuous forests. We analyzed anuran assemblages with respect to habitat characteristics, including fragmentation and degradation parameters. In comparison with continuous forests, species richness and diversity were lower and assemblage composition was altered in forest fragments. These changes seemed to be mainly caused by habitat degradation rather than forest fragmentation. Availability of aquatic sites for breeding, vegetation structure (including those variables indicating degradation), and leaf-litter cover had the most influence on the presence of single species. The comparatively small impact of fragmentation on anurans might be due to the location of the study area; it still possessed large tracts of continuous forest. These forest blocks may stabilize the regional rainforest climate and thus weaken the effects of fragmentation.

Patterns of community composition in two tropical tree frog assemblages: separating spatial structure and environmental effects in disturbed and undisturbed forests

Abstract:An on-going controversy in community ecology involves the debate about the many factors that affect the assembly and composition of a given species assemblage. Theory suggests that community composition is influenced by environmental gradients or biotic processes. This study examines patterns of community composition in two tropical tree frog assemblages of primary and exploited lowland rain-forest sites in the Guiana Shield area of central Guyana, South America and the Upper Guinean rain-forest block of south-western Côte d'Ivoire, West Africa. We tested community composition and species abundance data of two adult tree frog communities collected on 21 standardized transects during a period of 5 y for evidence of spatial correlation in community composition. We applied simple and partial Mantel tests to separate the effects of environmental variables, spatial distance and spatial autocorrelation on community composition. Whenever environmental effects were accounted for, we found significant positive spatial correlation of community composition. All assemblages appeared to be spatially structured, i.e. sites in close proximity had similar species assemblages. However, spatially structured environmental variation (autocorrelation) did not account for the spatial structure of species incidence. Environmental factors did not prove to be significant predictors of species incidence in any of the assemblages analysed, even if we controlled for spatial effects. Observed correlation patterns of species composition were consistent within respective realms and disturbance regimes. Moreover, general correlation patterns were consistent between geographic regions. These results are in contrast to previously published results from a study on leaf-litter anurans and indicate that group-specific differences must not be neglected when analysing patterns of species composition in anurans as they may drastically alter the outcome of the analysis.

Acoustic signals, species diagnosis, and species concepts: the case of a new cryptic species of Leptodactylus (Amphibia, Anura, Leptodactylidae) from the Chapare region, Bolivia

Overall morphological similarity and intrapopulation variation of morphological features make species identification in cryptic species complexes challenging. In such cases, additional features, such as acoustic and/or genetic characters, are being used to aid species identification. The use of acoustic signals as a suite of diagnostic features can be especially rewarding in certain taxonomic groups that rely on acoustic communication. Such is the case of the Neotropical leaf litter frogs of the Leptodactylus marmoratus group (formerly Adenomera). Recent studies using different suites of features for field identification have revealed a previously undetected species richness for this group. It is in the light of acoustic signals that we identify a new species for this group, and describe it herein. We also discuss the systematics of populations associated with the Amazonian realm. We further explore the use of acoustic signals in species identification and diagnosis in anurans and other taxa that communicate acoustically (e.g. lacewings, orthopterans, and birds), and the relevance and importance of the use of species concepts in species diagnosis and descriptions.

Acoustic signals, species diagnosis, and species concepts: the case of a new cryptic species of Leptodactylus (Amphibia, Anura, Leptodactylidae) from the Chapare region, Bolivia

Overall morphological similarity and intrapopulation variation of morphological features make species identification in cryptic species complexes challenging. In such cases, additional features, such as acoustic and/or genetic characters, are being used to aid species identification. The use of acoustic signals as a suite of diagnostic features can be especially rewarding in certain taxonomic groups that rely on acoustic communication. Such is the case of the Neotropical leaf litter frogs of the Leptodactylus marmoratus group (formerly Adenomera). Recent studies using different suites of features for field identification have revealed a previously undetected species richness for this group. It is in the light of acoustic signals that we identify a new species for this group, and describe it herein. We also discuss the systematics of populations associated with the Amazonian realm. We further explore the use of acoustic signals in species identification and diagnosis in anurans and other taxa that communicate acoustically (e.g. lacewings, orthopterans, and birds), and the relevance and importance of the use of species concepts in species diagnosis and descriptions. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 152, 59–77.

Cryptic diversity and deep divergence in an upper Amazonian leaflitter frog, Eleutherodactylus ockendeni

BackgroundThe forests of the upper Amazon basin harbour some of the world's highest anuran species richness, but to date we have only the sparsest understanding of the distribution of genetic diversity within and among species in this region. To quantify region-wide genealogical patterns and to test for the presence of deep intraspecific divergences that have been documented in some other neotropical anurans, we developed a molecular phylogeny of the wide-spread terrestrial leaflitter frog Eleutherodactylus ockendeni (Leptodactylidae) from 13 localities throughout its range in Ecuador using data from two mitochondrial genes (16S and cyt b; 1246 base pairs). We examined the relation between divergence of mtDNA and the nuclear genome, as sampled by five species-specific microsatellite loci, to evaluate indirectly whether lineages are reproductively isolated where they co-occur. Our extensive phylogeographic survey thus assesses the spatial distribution of E. ockendeni genetic diversity across eastern Ecuador.ResultsWe identified three distinct and well-supported clades within the Ecuadorean range of E. ockendeni: an uplands clade spanning north to south, a northeastern and central lowlands clade, and a central and southeastern clade, which is basal. Clades are separated by 12% to 15% net corrected p-distance for cytochrome b, with comparatively low sequence divergence within clades. Clades marginally overlap in some geographic areas (e.g., Napo River basin) but are reproductively isolated, evidenced by diagnostic differences in microsatellite PCR amplification profiles or DNA repeat number and coalescent analyses (in MDIV) best modelled without migration. Using Bayesian (BEAST) and net phylogenetic estimates, the Southeastern Clade diverged from the Upland/Lowland clades in the mid-Miocene or late Oligocene. Lowland and Upland clades speciated more recently, in the early or late Miocene.ConclusionOur findings uncover previously unsuspected cryptic species diversity within the common leaflitter frog E. ockendeni, with at least three different species in Ecuador. While these clades are clearly geographically circumscribed, they do not coincide with any existing landscape barriers. Divergences are ancient, from the Miocene, before the most dramatic mountain building in the Ecuadorean Andes. Therefore, this diversity is not a product of Pleistocene refuges. Our research coupled with other studies suggests that species richness in the upper Amazon is drastically underestimated by current inventories based on morphospecies.

Applying new inter-individual approaches to assess fine-scale population genetic diversity in a neotropical frog, Eleutherodactylus ockendeni

We assess patterns of genetic diversity of a neotropical leaflitter frog, Eleutherodactylus ockendeni, in the upper Amazon of Ecuador without a priori delineation of biological populations and with sufficiently intensive sampling to assess inter-individual patterns. We mapped the location of each collected frog across a 5.4 x 1 km landscape at the Jatun Sacha Biological Station, genotyped 185 individuals using five species-specific DNA microsatellite loci, and sequenced a fragment of mitochondrial cytochrome b for a subset of 51 individuals. The microsatellites were characterized by high allelic diversity and homozygote excess across all loci, suggesting that when pooled the sample is not a panmictic population. We conclude that the lack of panmixia is not attributable to the influence of null alleles or biased sampling of consanguineous family groups. Multiple methods of population cluster analysis, using both Bayesian and maximum likelihood approaches, failed to identify discrete genetic clusters across the sampled area. Using multivariate spatial autocorrelation, kinship coefficients and relatedness coefficients, we identify a continuous isolation by distance population structure, with a first patch size of ca. 260 m and apparently large population sizes. Analysis of mtDNA corroborates the observation of high genetic diversity at fine scales: there are multiple haplotypes, they are non-randomly distributed and a binary haplotype correlogram shows significant spatial genetic autocorrelation. We demonstrate the utility of inter-individual genetic methods and caution against making a priori assumptions about population genetic structure based simply on arbitrary or convenient patterns of sampling.