Lowland Fauna Research Articles

Three new extinct species from the endemic Philippine cloud rat radiation (Rodentia, Muridae, Phloeomyini)

AbstractThe 18 extant members of the Tribe Phloeomyini, the “cloud rats,” constitute an endemic Philippine radiation of arboreal herbivores that range in size from ca. 18 g to 2.7 kg, most occurring in cloud forest above 1,200 m elevation. Although calibrated phylogenies indicate that the Phloeomyini is estimated to have begun diversifying within the Philippines by ca. 10–11 million years ago, no extinct fossil species have been described, severely limiting our understanding of this distinctive radiation. Our studies of fossil and subfossil small mammal assemblages from the lowland Callao Caves complex in NE Luzon, Philippines, have produced specimens of Phloeomyini that date from ca. 67,000 BP to the Late Holocene (ca. 4,000 to 2,000 BP). We identify three extinct species that we name as new members assigned to the genera Batomys, Carpomys, and Crateromys, distinguished from congeners by body size, distinctive dental and other morphological features, and occupancy of a habitat (lowland forest over limestone) that differs from the high-elevation mossy forest over volcanic soils occupied by their congeners. Batomys cagayanensis n. sp. is known only from two specimens from ca. 67,000 BP; Carpomys dakal n. sp. and Crateromys ballik n. sp. were present from ca. 67,000 BP to the Late Holocene. These add to the species richness and morphological diversity of this endemic Philippine radiation of large folivores, and show specifically that the lowland fauna of small mammals on Luzon was more diverse in the recent past than it is currently, and that Luzon recently supported five species of giant rodents (ca. 1 kg or more). All three occurred contemporaneously with Homo luzonensis, and two, the new Carpomys and Crateromys, persisted until the Late Holocene when multiple exotic mammal species, both domestic and invasive, were introduced to Luzon, and new cultural practices (such as making pottery) became evident, suggesting that modern humans played a role in their extinction.

Interactions in multi-pattern M\xfcllerian communities support origins of new patterns, false structures, imperfect resemblance and mimetic sexual dimorphism

Mimicry is a hot spot of evolutionary research, but de novo origins of aposematic patterns, the persistence of multiple patterns in Müllerian communities, and the persistence of imperfect mimics still need to be investigated. Local mimetic assemblages can contain up to a hundred of species, their structure can be a result of multiple dispersal events, and the gradual build-up of the communities. Here, we investigate the structure of lowland and mountain mimetic communities of net-winged beetles by sampling the Crocker Range in north-eastern Borneo and neighbouring regions. The local endemics evolved from the Bornean lowland fauna which is highly endemic at the species level. We inferred that metriorrhynchine net-winged beetles evolved in high elevations yellow/black and reticulate aposematic high-contrast signals from a widespread low-contrast brown/black pattern. As the mountain range is ~ 6 million years old, and these patterns do not occur elsewhere, we assume their in situ origins. We demonstrate that a signal with increased internal contrast can evolve de novo in a mimetic community and can persist despite its low frequency. Additionally, a similar aposematic signal evolves from different structures and its similarity is imperfect. The community with multiple patterns sets conditions for the evolution of aposematic sexual dimorphism as demonstrated by the yellow/black male and reticulate female pattern of Micronychus pardus. These insights elucidate the complex character of the evolution of mimetic signalling in the dynamically diversifying biota of high tropical mountains.

Transitions between Andean and Amazonian centers of endemism in the radiation of some arboreal rodents

BackgroundThe tropical Andes and Amazon are among the richest regions of endemism for mammals, and each has given rise to extensive in situ radiations. Various animal lineages have radiated ex situ after colonizing one of these regions from the other: Amazonian clades of dendrobatid frogs and passerine birds may have Andean ancestry, and transitions from the Amazon to Andes may be even more common. To examine biogeographic transitions between these regions, we investigated the evolutionary history of three clades of rodents in the family Echimyidae: bamboo rats (Dactylomys-Olallamys-Kannabateomys), spiny tree-rats (Mesomys-Lonchothrix), and brush-tailed rats (Isothrix). Each clade is distributed in both the Andes and Amazonia, and is more diverse in the lowlands. We used two mitochondrial (cyt-b and 12S) and three nuclear (GHR, vWF, and RAG1) markers to reconstruct their phylogenetic relationships. Tree topologies and ancestral geographic ranges were then used to determine whether Andean forms were basal to or derived from lowland radiations.ResultsFour biogeographic transitions are identified among the generic radiations. The bamboo rat clade unambiguously originated in the Amazon ca. 9 Ma, followed by either one early transition to the Andes (Olallamys) and a later move to the Amazon (Dactylomys), or two later shifts to the Andes (one in each genus). The Andean species of both Dactylomys and Isothrix are sister to their lowland species, raising the possibility that highland forms colonized the Amazon Basin. However, uncertainty in their reconstructed ancestral ranges obscures the origin of these transitions. The lone Andean species of Mesomys is confidently nested within the lowland radiation, thereby indicating an Amazon-to-Andes transition ca. 2 Ma.ConclusionsDifferences in the timing of these biogeographic transitions do not appear to explain the different polarities of these trees. Instead, even within the radiation of a single family, both Andean and Amazonian centers of endemism appear enriched by lineages that originated in the other region. Our survey of other South American lineages suggests a pattern of reciprocal exchange between these regions—among mammals, birds, amphibians, and insects we found no fewer than 87 transitions between the Andes and Amazon from Miocene-Pleistocene. Because no clear trend emerges between the timing and polarity of transitions, or in their relative frequency, we suggest that reciprocal exchange between tropical highland and lowland faunas in South America has been a continual process since ca. 12 Ma.

Andean uplift promotes lowland speciation through vicariance and dispersal in Dendrocincla woodcreepers

Andean uplift contributed importantly to the build-up of high Neotropical diversity. Final uplift of the Eastern Cordillera of Colombia separated once-contiguous lowland faunas east and west of the Andes between 5 and 3.5 million years ago (Ma hereafter). We used DNA sequences from several moderate- to fast-evolving mitochondrial and two slow-evolving nuclear genes to generate a well-supported phylogeny of Dendrocincla woodcreepers, a genus with multiple species endemic to lowland regions both east and west of the Andes. A time-calibrated phylogeny and dispersal-vicariance analysis indicated that uplift of the Eastern Cordillera of Colombia resulted in the initial vicariant separation of a widespread lowland form east and west of the Andes at c. 3.6 Ma. This was followed by two separate east-to-west dispersal events over or around the completed Andes, each producing a genetically distinct lineage. Our analysis suggests that Andean uplift promoted the build-up of biodiversity in lowland Neotropical faunas both through vicariance-based speciation during uplift and through dispersal-based speciation following uplift. In contrast to the multiple colonizations of the trans-Andean region by Dendrocincla, the Atlantic Forest was colonized from the Amazon only once, followed by in situ diversification.

Land Snail Faunas in Polish Forests: Patterns of Richness and Composition in a Post-Glacial Landscape

We examine variation in species richness, species composition and distance decay in similarity in forest snail faunas from Poland and a small part of Transcarpathian Ukraine, and their connection with geographical position in relation to Pleistocene refugia. Forest faunas were sampled from sites of standard size in each of ten regions. Data were analysed using DCA and partial CCA, extracting the geographical, climatic and ecological correlates with the major axes. Relationships among site and regional faunas were further examined through the Simpson Index of Similarity. Site species richness shows no significant variation with geographical position or climate, but relates to soil and vegetation characteristics. Composition varies with location; southern highland faunas differ from one another far more than do northern lowland faunas, showing a clear east-to-west pattern of change. The aggregate highland fauna is richer than that of the lowlands, which is a subset of the former. Two intermediate upland regions show different associations, one with the highlands the other with the lowlands. Lowland faunas, even over large distances, are very similar, and all relate more closely to the western end of the highlands than to the east. Disaggregating the fauna into large and small species shows that the former show a stronger geographical pattern than the latter; most universally distributed species are small. Latitudinal variation in regional richness, and longitudinal differentiation among highland faunas relate to distance from glacial refugia. This is not reflected in site species richness, raising questions about the assembly rules for local faunas. The western bias in the relationships of lowland faunas to those of the highlands, the differences between large and small species and the varying rates of faunal turnover within the area studied suggest that patterns of post-glacial dispersal are complex and incompletely understood.

Elevational Patterns of Diversity and Abundance of Eusocial Paper Wasps (Vespidae) in Costa Rica

ABSTRACTWe used a standard sampling protocol to measure elevational patterns of species richness and abundance of eusocial paper wasps (Hymenoptera: Vespidae) in Costa Rica. The sample transect of six sites spanned approximately 2000 m in elevation from lowland to montane forest. Species accumulation curves and species richness estimates both document a low elevation peak in paper wasp species richness at 50 and 300 m asl, with a decline in species richness at higher elevations. Comparison of species composition among elevations revealed strong species turnover from a rich lowland fauna to a depauperate, but distinct, montane fauna. We also observed a general trend toward a greater abundance of paper wasps at higher elevations, a pattern not usually observed in eusocial insects. Army ant species that prey on paper wasps declined in abundance with elevation across the sample transect, a pattern that has been observed at other sites. We discuss the possibility that elevational changes in predation pressure affect variation in paper wasp abundance and species richness. Eusocial paper wasp species employ one of two modes of colony founding, independent and swarm founding. We found that the total abundance of individual swarm‐founding wasps was higher at all elevations than the abundance of independent‐founding wasps, supporting previous suggestions that Neotropical swarm founders are more successful ecologically.

The effect of fine sedimentation on tropical stream macroinvertebrate assemblages: a comparison using flow-through artificial stream channels and recirculating mesocosms

In-situ artificial stream channels and ex-situ laboratory mesocosms were used to measure the responses of macroinvertebrate assemblages, from upland and lowland tropical streams, to high loads of fine clay sediment. Significant responses were observed mainly in the in-situ channels in the upland stream, where densities and the number of taxa were lower in the treatment channels than in controls. There was no evidence of any taxon being particularly sensitive to sedimentation, with a general decrease in densities across several taxa and differences only detectable for abundant taxa. Animals moved downstream in response to the treatment, but only a short distance within the channels. However, further colonization after the treatment was impeded in the treatment channels. In the mesocosm experiments, the upland macroinvertebrate assemblage demonstrated some negative effects; however, the lowland fauna was very tolerant to sedimentation, even when exposure was extended to 15 days. Together, the mesocosm and in-situ experiments indicate that there is a behavioural response to sedimentation because of a change in the habitat, and that the lowland macroinvertebrate assemblage is more tolerant of sedimentation, at least in the short term.

Ecological and biogeographical characteristics of butterflies (Lepidoptera, Rhopalocera) of Vietnam

The lowland butterfly fauna in Vietnam is more diversified whereas the mountain fauna is more specific and contains more endemic taxa. The lowland areas have significantly higher levels of species richness (51–86%) as compared to the mountainous areas (25–66%). The aspect of the fauna shows a well-developed seasonality, with higher species diversity during the dry period and in the transitional period between the dry and rainy seasons. The butterfly fauna of Vietnam should be regarded not as a transitional one between the faunas of the Holarctic and Indo-Malayan Regions, but as one of the principal faunas of the Indo-Malayan Region, constituting the core of the Indo-Burmese fauna and including representatives of the neighboring faunistic centers.

DIVERGENT TIMING AND PATTERNS OF SPECIES ACCUMULATION IN LOWLAND AND HIGHLAND NEOTROPICAL BIRDS

Late Pliocene and Pleistocene climatic instability has been invoked to explain the buildup of Neotropical biodiversity, although other theories date Neotropical diversification to earlier periods. If these climatic fluctuations drove Neotropical diversification, then a large proportion of species should date to this period and faunas should exhibit accelerated rates of speciation. However, the unique role of recent climatic fluctuations in promoting diversification could be rejected if late Pliocene and Pleistocene rates declined. To test these temporal predictions, dateable molecular phylogenies for 27 avian taxa were used to contrast the timing and rates of diversification in lowland and highland Neotropical faunas. Trends in diversification rates were analyzed in two ways. First, rates within taxa were analyzed for increasing or decreasing speciation rates through time. There was a significant trend within lowland taxa towards decreasing speciation rates, but no significant trend was observed within most highland taxa. Second, fauna wide diversification rates through time were estimated during one-million-year intervals by combining rates across taxa. In the lowlands, rates were highest during the late Miocene and then decreased towards the present. The decline in rates observed both within taxa and for the fauna as a whole probably resulted from density dependent cladogenesis. In the highlands, faunawide rates did not vary greatly before the Pleistocene but did increase significantly during the last one million years of the Pleistocene following the onset of severe glacial cycles in the Andes. These contrasting patterns of species accumulation suggest that lowland and highland regions were affected differently by recent climatic fluctuations. Evidently, habitat alterations associated with global climate change were not enough to promote an increase in the rate of diversification in lowland faunas. In contrast, direct fragmentation of habitats by glaciers and severe altitudinal migration of montane vegetation zones during climatic cycles may have resulted in the late Pleistocene increase in highland diversification rates. This increase resulted in a fauna with one third of its species dating to the last one million years.

DIVERGENT TIMING AND PATTERNS OF SPECIES ACCUMULATION IN LOWLAND AND HIGHLAND NEOTROPICAL BIRDS

Late Pliocene and Pleistocene climatic instability has been invoked to explain the buildup of Neotropical biodiversity, although other theories date Neotropical diversification to earlier periods. If these climatic fluctuations drove Neotropical diversification, then a large proportion of species should date to this period and faunas should exhibit accelerated rates of speciation. However, the unique role of recent climatic fluctuations in promoting diversification could be rejected if late Pliocene and Pleistocene rates declined. To test these temporal predictions, dateable molecular phylogenies for 27 avian taxa were used to contrast the timing and rates of diversification in lowland and highland Neotropical faunas. Trends in diversification rates were analyzed in two ways. First, rates within taxa were analyzed for increasing or decreasing speciation rates through time. There was a significant trend within lowland taxa towards decreasing speciation rates, but no significant trend was observed within most highland taxa. Second, fauna wide diversification rates through time were estimated during one-million-year intervals by combining rates across taxa. In the lowlands, rates were highest during the late Miocene and then decreased towards the present. The decline in rates observed both within taxa and for the fauna as a whole probably resulted from density dependent cladogenesis. In the highlands, faunawide rates did not vary greatly before the Pleistocene but did increase significantly during the last one million years of the Pleistocene following the onset of severe glacial cycles in the Andes. These contrasting patterns of species accumulation suggest that lowland and highland regions were affected differently by recent climatic fluctuations. Evidently, habitat alterations associated with global climate change were not enough to promote an increase in the rate of diversification in lowland faunas. In contrast, direct fragmentation of habitats by glaciers and severe altitudinal migration of montane vegetation zones during climatic cycles may have resulted in the late Pleistocene increase in highland diversification rates. This increase resulted in a fauna with one third of its species dating to the last one million years.

Rodent communities in the sub-polar Ural mountains

Distribution of the rodent communities in the Sub-polar Urals is analysed. This part of the range, between 64° and 66°N, includes the highest peaks, is very scarcely settled and has been rarely studied. However, the area is interesting for biogeography, being a border zone separating European and Siberian lowland faunas. Comparison of results with those from expeditions undertaken in 1927 and in 1972, allows to evaluate changing trends in the local rodent communities, and to relate these trends to changes in the environmental conditions. The results help to emphasize the barrier role played by Sub-polar Urals for the species of rodents inhabiting both sides of the range, and also show the shifting of southern rodent forms northwards, or the moving upwards of other lowland species. This could be seen as an additional evidence of current climate warming trends.

Biological diversification in a complex region: a spatial analysis of faunistic diversity and biogeography of the Andes of Colombia

AbstractAim Understanding large‐scale patterns of beta diversity and endemism is essential for ecoregional conservation planning. We present a study of spatial patterns of faunal diversification and biogeographical relationships in the Andean region of Colombia. This region has a great geomorphological complexity, as it is formed by several mountain ranges with different geologic origins. We hypothesize that this complexity results in a high turnover in species composition among subregions.Location The Andean region of Colombia, including the Santa Marta and Macarena mountain ranges.Methods The region was divided into subregions, represented by the eastern and western slopes of each of the three Andean cordilleras, the Cauca and Magdalena valley bottoms, and the peripheral mountain ranges of Perijá, Macarena and Sierra Nevada de Santa Marta. Species lists for five animal taxa (rodents, bats, birds, frogs and butterflies) were compiled for each subregion and similarities in species composition were determined by cluster analysis. To explore biogeographical relationships, species were classified into one of four distributional categories: endemic, tropical Andean, Andean‐Central American and wide continental distribution.Results The highest species richness in the region was found in the Pacific and eastern versants of the Andes, and the lowest in the Cauca and Magdalena valley bottoms. Inter‐Andean slopes were intermediate in species richness. However, when species richness was calculated per unit area, the most diverse regions were the Santa Marta and Macarena ranges, the Cauca Valley watershed and the Pacific slope. Although each taxonomic group had a different branching pattern, dendrograms indicated five common subregional clusterings: (1) Perijá‐Sierra Nevada, (2) the Pacific slope, (3) the eastern Andean slope, (4) the Cauca and Magdalena valley bottoms, and (5) the inter‐Andean slopes. Clustering patterns of inter‐Andean slopes varied among taxa. In birds, bats and rodents, grouping was by opposite slopes of the same valley, whereas frogs were grouped by mountain ranges and butterflies by valleys and their respective slopes. Seventy‐five per cent of species in all taxa were found in less than five subregions. The fauna of the Magdalena and Cauca valley bottoms was composed mostly of lowland species with wide geographical distributions, whereas the cordilleran fauna was mostly restricted to the tropical Andes.Main conclusions The western and eastern versants of the Andes have the highest species richness, but are also the largest subregions. On a per unit area basis, the peripheral ranges (Santa Marta and Macarena) are the richest, followed by the western portion of the Andes (the Cauca Valley watershed and the Pacific versant). Clustering patterns in dendrograms suggest two major patterns of differentiation of the Andean fauna: one elevational (lowlands vs. highlands) and one horizontal (among ranges and/or slopes). Biogeographical affinities of the inter‐Andean valley bottoms are with the lowland faunas of tropical America. In contrast, Andean faunas diversified locally, resulting in the evolution of a large number of endemic species, particularly among the less vagile taxa. Three different main branches of Andean fauna can be recognized, one confined to the Pacific, another to the eastern (Amazonian‐Llanos) versant of the Andes, and the third one composed by the inter‐Andean slopes of the Cauca and Magdalena valleys. The identification of five main biogeographical units in the Andean region of Colombia has important implications for the conservation of the regional biota. Conservation initiatives that seek to preserve representative samples of the regional biodiversity should take into account the patterns of diversification described here, and the evolutionary processes that gave rise to these patterns.

The biodiversity of Diptera in Old World rain forest surveys: a comparative faunistic analysis

AbstractAim Identify the taxonomic patterns and the relative importance of particular families of Diptera sampled in comparative biodiversity surveys carried out at seven rain forest locations. We test and quantify the contention that different trapping methods routinely target different families. We identify the south–north (and upland/lowland) patterns and generate a set of hypotheses concerning mechanisms underlying these patterns.Location Australia and Papua New Guinea.Methods A total of 28,647 Diptera collected using canopy knockdown, yellow pan (water) traps and Malaise traps have been sorted to 56 families following these surveys. Comparative analyses across sites from Lamington National Park in south‐east Queensland, Australia to the Kau Wildlife area in Madang Province, Papua New Guinea, of the dipteran assemblages, and separately, of the 14 families which collectively made up 95.8% of the sample, are presented.Results Ordination by multi‐dimensional scaling and analyses of variances showed that the three methods complemented each other in terms of target families and, together, sampled a large proportion of the expected fauna of these sites. Ordinations on a method‐by‐method basis permitted the identification of groups of sites and analyses of variance indicated which taxa differed significantly across these groups.Main conclusions Recurrent patterns and associated hypotheses about their generation emerge from the data. These mirror floristic differences and reflect the biogeographic history of the sites since the Miocene. Clear linkages between the lowland faunas of Papua New Guinea and northern Australia are evident and are reflected in the abundances of the Dolichopodidae, Empididae, Muscidae and Tipulidae (other groupings underlined the essential difference of the New Guinean fauna which had characteristic proportions of Cecidomyiidae, Chironomidae, Dolichopodidae, Phoridae and Psychodidae). A subtropical grouping of families was evident comprising, inter alia, Chloropidae, Mycetophilidae, Drosophilidae and Phoridae which was frequently linked with the higher elevation tropical fauna at Robson's Creek, Atherton Tablelands. The long isolated, high elevation, rain‐forested massif at Eungella, central Queensland often emerged as a unique entity in the analyses, characterized by the high numbers of and proportions of Chironomidae, Psychodidae, Tipulidae and Empididae. This study supports the case for the wider use of Diptera in biodiversity analyses, complementing extensive earlier analyses which have used, predominantly, large coleopteran assemblages. The results indicate the potential power of family‐level analyses at large geographical scales and contribute to the ongoing debate on ‘taxonomic sufficiency’.

Altitudinal species turnover in southern Tanzania shown by anurans: Some zoogeographical considerations

A transect was used to investigate the pattern of altitudinal species turnover shown by the rich fauna of frogs and toads in southeastern Tanzania, and to compare the pattern with those shown by transects taken further south. The transect, taken from the Udzungwa range to the southeastern coast, was divided into 50 m intervals. As with the southern transects, there appears to be a major grouping into lowland and highland sets, with opposing and overlapping subtraction margins that form a replacement‐transition zone. A distributionally complex assemblage of species occurs in this zone. When a similarity value (the Dice‐Sørensen index, expressed as a percentage) taken between the montane ridge and lowland faunas was compared with those of the southern transects, a markedly higher species turnover (low similarity value) is shown in Tanzania. Both lowland and highland faunas have more species than equivalent faunas to the south; the highland fauna is particularly rich in genera not known to occur further south. Yet overall, the pattern of altitudinal turnover shown in the Tanzanian transect is in agreement with the pattern shown in the southern transects. The transects discussed in this paper, combined with other evidence, suggest a need for re‐evaluating the common practice of including all sub‐Saharan Africa in a single so‐called Afrotropical Region.

Species composition of termites of the Nyika plateau forests, northern Malawi, over an altitudinal gradient

AbstractTermites were surveyed at three altitudes (Brachystegia woodland at 1676 m and 1905 m, and Juniper woodland at 2210 m) in forests within the Nyika Plateau, northern Malawi. Sampling was by a standardized 100 m transect protocol. Termite diversity was highest in the mid‐altitude site and lowest in the Juniper forest. The assemblages were dominated by soil‐feeding termites in the Termitidae subfamilies Apicotermitinae and Termitinae, and included one new soldierless Apicotermitinae genus. The structure of the assemblages was clearly due to a mixture of altitudinal and site history factors. This was especially true of the lowest altitude forest where burning and other anthropogenic disturbance factors appear to have reduced termite diversity relative to the mid‐altitude site. The Nyika plateau shows a much higher diversity at mid‐altitudes than similar SE Asian sites, probably due to the larger area of highland in Africa than in SE Asia. In addition, the clade composition of the Nyika assemblages differs completely from that found at similar altitudes in SE Asia. This preliminary study supports the hypothesis that mid‐ to high‐ altitude assemblages in both SE Asia and Africa appear to be derived from depauperated random subsets of the lowland fauna rather than from clades specifically adapted to higher altitudes.

Patterns of Richness and Abundance in a Tropical African Leaf‐litter Herpetofauna1

ABSTRACTI compared species richness and habitat correlates of leaf‐litter herpetofaunal abundance in undisturbed and selectively logged forests, and an abandoned pine plantation in Kibale National Park, Uganda. I sampled 50 randomly located 25 m2 litter plots in each area during the wet and dry seasons in 1997. Ten anuran, five lizard, and three snake species were captured in plots over the study. Assemblage composition was most similar at logged and unlogged sites. The logged forest herpetofauna had higher species richness and abundance than the unlogged forest, but diversity was greater in the unlogged forest due to greater evenness. In contrast, the pine plantation site had the highest richness, abundance, and evenness of the three study sites, but species composition was distinct from the other areas. Herpetofaunal densities were significantly lower in all three areas during the dry season than in the wet season. During the dry season, soil moisture, litter mass, topography, shrub cover, and number of fallen logs were significant positive predictors of herpetofaunal presence in litter plots, but only soil moisture was significant in the wet season. The interaction of moisture and topography appears to be important in determining seasonal patterns of litter herpetofaunal distribution. Comparison of litter herpetofaunal studies across the tropics have shown that mid‐elevation faunas generally support fewer species than lowland faunas. Compared with other tropical mid‐elevation litter faunas, Kibale supports an intermediate number of species, but at lower densities than observed at any other mid‐elevation site reported in the literature.

Patterns of Richness and Abundance in a Tropical African Leaf-litter Herpetofauna1

I compared species richness and habitat correlates of leaf-litter herpetofaunal abundance in undisturbed and selectively logged forests, and an abandoned pine plantation in Kibale National Park, Uganda. I sampled 50 randomly located 25 m2 litter plots in each area during the wet and dry seasons in 1997. Ten anuran, five lizard, and three snake species were captured in plots over the study. Assemblage composition was most similar at logged and unlogged sites. The logged forest herpetofauna had higher species richness and abundance than the unlogged forest, but diversity was greater in the unlogged forest due to greater evenness. In contrast, the pine plantation site had the highest richness, abundance, and evenness of the three study sites, but species composition was distinct from the other areas. Herpetofaunal densities were significantly lower in all three areas during the dry season than in the wet season. During the dry season, soil moisture, litter mass, topography, shrub cover, and number of fallen logs were significant positive predictors of herpetofaunal presence in litter plots, but only soil moisture was significant in the wet season. The interaction of moisture and topography appears to be important in determining seasonal patterns of litter herpetofaunal distribution. Comparison of litter herpetofaunal studies across the tropics have shown that mid-elevation faunas generally support fewer species than lowland faunas. Compared with other tropical mid-elevation litter faunas, Kibale supports an intermediate number of species, but at lower densities than observed at any other mid-elevation site reported in the literature.

Evidence for an Afrotemperate amphibian fauna

Latitudinal and altitudinal changes in composition of the African amphibian fauna is analysed to test the standard zoogeographical division of the continent into Palaearctic and Afrotropical Regions. A comparably high faunal change north and south of the. tropical savannas suggests that it is inappropriate to classify the south-temperate fauna as “Afrotropical”. High geographical turnover between lowland and montane faunas north of the Cape likewise suggests the inappropriateness of classifying the fauna of the Afromontane archipelago as “Afrotropical”. Although extending into the cartographic tropics, the area occupied by the temperate amphibian fauna lies outside the climatic tropics and covers the same general area as the Afrotemperate flora. This supports a division into three regions: Palaearctic, Afrotropical (in a restricted sense) and Afrotemperate. Account has to be taken of extensive transition zones between areas occupied by tropical and temperate amphibian faunas, and the Nile Delta is considered to show the typical features of a transition zone rather than be included in the Palaearctic Region as is usually done. Taxonomic differences are evident between faunas of East and West Africa, most marked in forest habitats, yet it seems acceptable to include non-Afromontane east and west faunas in a single Afrotropical Region. Reptiles, birds and mammals do not show a tripartite Palaearctic-Afrotropical-Afrotemperate pattern as strongly as amphibians. This is not unexpected considering global distribution patterns. The amphibian pattern agrees with that of several invertebrate groups, and supports the proposal of dividing the world into three main regions, Austral, Holotropical and Holarctic.

Threat from deforestation to montane and lowland birds and mammals in insular South‐east Asia

Summary1. A reduction in forest area should result in a reduction of its number of species and, moreover, do so in a characteristic way according to the familiar species‐area relationship.Brooks, Pimm & Collar (1997)applied this formula to the losses in forest area in the Philippines and Indonesia. Independently derived totals of the number of endemic bird species that are threatened with extinction broadly agree with these predicted losses. In some cases, however, predicted losses overestimate or underestimate the actual numbers of threatened species.2. Within an island, the proportionate deforestation to date might be most extensive where there are many endemic species, or where there are few. To test this possibility, we obtained recent forest cover data for the region. We separated lowland (< 1000 m a.s.l.) from montane (> 1000 m a.s.l.) forest cover by overlaying topographic maps. From these data, we predict separately the numbers of montane and lowland endemic bird species likely to become extinct as a result of deforestation. We then compared these totals with the numbers considered threatened in the latestRed List.3. Our predictions based on deforestation closely match the numbers of threatened endemic birds in the lowlands, but underestimate them in montane regions.4. Our predictions based on deforestation underestimate the number of threatened montane mammal species even more seriously.5. Lowland faunas of insular South‐east Asia are under extreme threat because of massive deforestation. The region's montane faunas appear seriously threatened even by low levels of deforestation.

Species turnover between Afromontane and eastern African lowland faunas: patterns shown by amphibians

Abstract. Following the recognition of a discrete East African lowland amphibian fauna (Poynton, 1990), this paper investigates the possible recognition of an Afromontane amphibian fauna in southern Africa. Species turnover in a transect from the Mozambique/KwaZulu‐Natal border area through Swaziland to the Eastern Transvaal highveld is described, and compared with previously described transects through Mozambique to Zimbabwe, and KwaZulu‐Natal to the central Free State. Turnover in the Swaziland transect shows two peaks. Marked turnover at the edge of the interior plateau is taken to indicate an eastern border of an Afromontane fauna; the other peak, at the western edge of the coastal lowland, is taken to mark the border of an East African lowland fauna. A transition zone with a transitional assemblage occurs on the plateau slopes between the two borders. The Zimbabwean transect shows a similar pattern. The KwaZulu‐Natal to Free State transect shows a broad transition from upland to lowland assemblages, which parallels the extensive intermingling of upland and lowland floristic elements in that area. A north‐south turnover across the three transects shows northern species becoming progressively excluded from highland areas as they extend southwards, while southern species become limited to the highlands as they extend northwards. The cohesive north‐south turnover pattern is consistent with the idea of a single Afromontane biogeographical unit, which can be related to a tropical East African lowland unit through a complex pattern of species turnover.