Relationship Between Microhabitat Structure and Distribution of Mouse Lemurs (Microcebus spp.) in Northwestern Madagascar

Understanding processes affecting the distribution and abundance of organisms is a central issue in ecology and conservation biology. In northwestern Madagascar, we found an uneven distribution pattern of the golden-brown mouse lemur (Microcebus ravelobensis) and the grey mouse lemur (M. murinus). In one area (JBA) the two species lived sympatrically, whereas in another forest area (JBB) Microcebus ravelobensis occurred exclusively. To investigate whether differences in forest structure may explain this uneven distribution, we conducted a microhabitat analysis and related it to specific distribution. In JBA the habitat of Microcebus ravelobensis was characterized by a higher percentage of trees with many lianas and a higher cover of the herb layer, whereas that of M. murinus had a higher number of trees with a diameter at breast height (DBH) >10 cm. The comparison of the forest structure of the microhabitats of the two species between JBA and JBB revealed further differences. The cover of the overstory, the percentage of trees without lianas and the number of larger trees (DBH >10 cm) among the microhabitats were higher for Microcebus murinus in JBA than for M. ravelobensis in JBB whereas the microhabitats of M. ravelobensis at the two sites did not differ concerning these vegetation structures. Differences between the two species coincide with those of resources important for survival. Our results indicate the importance of microhabitat analyses for the understanding of distribution patterns of species and for successful conservation planning.     

Range reshuffling: Climate change,invasive species,and the case of Nothofagus forests in Aotearoa New Zealand

Aim

The impact of climate change on forest biodiversity and ecosystem services will be partly determined by the relative fortunes of invasive and native forest trees under future conditions. Aotearoa New Zealand has high conservation value native forests and one of the world's worst invasive tree problems. We assess the relative effects of habitat redistribution on native Nothofagus and invasive conifer (Pinaceae) species in New Zealand as a case study on the compounding impacts of climate change and tree invasions.

Location

Aotearoa New Zealand.

Methods

We use species distribution models (SDMs) to predict the current and future distribution of habitat for five native Nothofagus species and 13 invasive conifer species under two 2070 climate scenarios. We calculate habitat loss/gain for all species and examine overlap between the invasive and native species now and in future.

Results

Most species will lose habitat overall. The native species saw large changes in the distribution of habitat with extensive losses in North Island and gains mostly in South Island. Concerningly, we found that most new habitat for Nothofagus was also suitable for at least one invasive species. However, there were refugia for the native species in the wetter parts of the climate space.

Main Conclusion

If the predicted changes in habitat distribution translate to shifts in forest distribution, it would cause widespread ecological disruption. We discuss how acclimation, adaptation and biotic interactions may prevent/delay some changes. But we also highlight that the poor establishment capacity of Nothofagus, and the contrasting ability of the conifers to invade, will present persistent conservation challenges in areas of both new habitat and forest retreat. Pinaceae are problematic invaders globally, and our results highlight that control of invasions and active native forest restoration will likely be key to managing forest biodiversity under future climates.     

Habitat preference in the critically endangered yellow‐tailed woolly monkey (Lagothrix flavicauda) at La Esperanza,Peru

Habitat loss is one of the main threats to wildlife. Therefore, knowledge of habitat use and preference is essential for the design of conservation strategies and identification of priority sites for the protection of endangered species. The yellow‐tailed woolly monkey (Lagothrix flavicauda Humboldt, 1812), categorized as Critically Endangered on the IUCN Red List, is endemic to montane forests in northern Peru where its habitat is greatly threatened. We assessed how habitat use and preference in L. flavicauda are linked to forest structure and composition. The study took place near La Esperanza, in the Amazonas region, Peru. Our objective was to identify characteristics of habitat most utilized by L. flavicauda to provide information that will be useful for the selection of priority sites for conservation measures. Using presence records collected from May 2013 to February 2014 for one group of L. flavicauda, we classified the study site into three different use zones: low‐use, medium‐use, and high‐use. We assessed forest structure and composition for all use zones using 0.1 ha Gentry vegetation transects. Results show high levels of variation in plant species composition across the three use zones. Plants used as food resources had considerably greater density, dominance, and ecological importance in high‐use zones. High‐use zones presented similar structure to medium‐ and low‐use zones; thus it remains difficult to assess the influence of forest structure on habitat preference. We recommend focusing conservation efforts on areas with a similar floristic composition to the high‐use zones recorded in this study and suggest utilizing key alimentation species for reforestation efforts.     

Genetic variation of an endangered Malagasy frog, <Emphasis Type="Italic">Mantella cowani</Emphasis>, and its phylogeographic relationship to the widespread <Emphasis Type="Italic">M. baroni</Emphasis>

We investigated the degree and distribution of the genetic variation, and phylogeography, of two species of Malagasy poison frogs, Mantella cowani and M. baroni. The former is critically endangered due to its restricted distribution, habitat destruction and overcollection for the pet trade. Analysis of 526 bp of mtDNA (cytochrome b) resulted in separate haplotype networks for the two species, and discovered hybridization at a single locality. The two networks confirm the status of M. baroni and M. cowani as separate evolutionary species and units for conservation. Within both mitochondrial haplotype networks, specimens from different localities shared numerous identical haplotypes, even those from the most distant sample sites of M. baroni. Most populations were characterized by high haplotype diversity and no haplotype clades exclusive to geographical regions were observed. Protection of a few large populations of these species is therefore likely to conserve much of the mtDNA genetic diversity found in the entire species. While M. baroni is widespread and occurs in many nature reserves, we recommend efficient legal protection of some M. cowani habitats to protect this species against extinction.     

A Revised Conservation Assessment of Dipterocarps in Sabah

Borneo has experienced a rapid decline in the extent of forest cover, which has reduced the amount of habitat available for many plant and animal species. The precise impact of habitat loss on the conservation status of dipterocarp trees is uncertain. We use three contrasting techniques, the extent of occurrence, area of occupancy and ecological niche models derived using maxent , in conjunction with a current land‐use map of Sabah, to derive estimates of habitat loss and infer a regional IUCN Red List conservation status for 33 Sabah dipterocarp species. Estimates of habitat loss differed significantly according to the methods employed and between species on different habitat types. Proportion of habitat loss determined from the ecological niche models varied from 21 percent for Shorea micans to 99.5 percent for Dipterocarpus lamellatus. Thirty‐two of the 33 dipterocarp species analyzed in this study would have their Sabah populations classified as Threatened (equal to a habitat loss of > 30%) under the A2 IUCN Red List criterion. Dipterocarps that occur in lowland forests have experienced greater habitat loss than upland/lower montane or ultramafic species. In addition, species with the lowest predicted area within their historic distributions had the highest proportion of habitat lost, which provides a rationale for targeting conservation effort on the species with narrow distributions. We recommend the ecological niche modeling approach as a rapid assessment tool for reconstructing species’ historic distributions during conservation assessments of tropical trees.     

Coexistence of two congeneric tree species of Lauraceae in a secondary warm‐temperate forest on Miyajima Island,south‐western Japan

We analyzed the spatial distributions of two congeneric tree species, Neolistea aciculata and Neolistea sericea (Lauraceae), in a warm‐temperate forest on Miyajima Island, south‐western Japan. Both species were mainly found in valley sites on the island. Hence, these species shared the same topographic habitat niche. However, we found a clear difference between the spatial distributions of the two species in relation to the light environment. Neolistea aciculata was predominantly found in stands with low light, such as beneath the canopy of dense evergreen broadleaved forest. In contrast, N. sericea was predominantly associated with ample light, such as in secondary Pinus densiflora forest. In stands with moderate light conditions, both species were found. This habitat niche segregation in relation to light conditions presumably allows the coexistence of these two species in the predominantly successional forest on Miyajima Island.     

Habitat relationships of forest birds on Tutuila Island, American Samoa

Aim Our knowledge of landbirds on tropical Pacific islands is often comprised of brief, one-time surveys. We know little of species’ habitat preferences, and this information is critical for understanding the resource requirements or population status of native species and the impacts of human activity on island birds. Location Tutuila Island, American Samoa. Methods The spatial patterns in forest birds were investigated. This island harbours large tracts of native forest, a variety of disturbed and non-native forests, and some relatively healthy bird populations. The distribution of birds was correlated with forest types using habitat data collected at fifty-seven sites and avian census data collected monthly for 1–4 years at these sites. Results Differences in location and in vegetation structure and composition between native and non-native habitats are important influences on the distribution of birds on Tutuila. Among native species, for example, the purple-capped fruit-dove (Ptilinopus porphyraceus Temminck) is dependent upon native habitat, the Samoan starling (Aplonis atrifusca Peale) occurs in all habitats, and the cardinal honeyeater (Myzomela cardinalis Gmelin) is more abundant in low elevation, non-native habitat. Conclusions This research reinforces the importance of quantitative assessment of habitat relationships in the study and conservation of Pacific birds.     

Studying Large Mammals With Imperfect Detection: Status and Habitat Preferences of Wild Cattle and Large Carnivores in Eastern Cambodia

Studying large mammal species in tropical forests is a conservation challenge with species’ behavior and ecology often increasing the probability of non‐detection during surveys. Consequently, knowledge of the distribution, status, and natural history of many large mammal species in Southeast Asia is limited. I developed occupancy models from camera‐trapping data, thereby accounting for imperfect detection at sampling sites, to clarify the status and habitat requirements of four globally threatened or near threatened large mammals (banteng Bos javanicus, gaur Bos gaurus, dhole Cuon alpinus, and leopard Panthera pardus) in Mondulkiri Protected Forest, eastern Cambodia. Camera traps were operational for >3500 trap nights with 202 photographic encounters of the four study species. Model averaged occupancy estimates were between 5 percent (leopard) and 140 percent (gaur) higher than naive estimates (i.e., proportion of camera‐trap sites species recorded from) thus highlighting the importance of accounting for detectability during conservation surveys. I recommend the use of an occupancy framework when using camera‐trap data to study the status, ecology, and habitat preferences of poorly known and elusive species. The results highlight the importance of mixed deciduous and semi‐evergreen forest for wild cattle in eastern Cambodia and I emphasize that these habitats must be considered in conservation planning across the Lower Mekong Dry Forest Ecoregion.     

Breeding-habitat use by five Amazonian frogs at forest edge

Understanding patterns of speciesl habitat use and their response to dramatic changes in habitat constitutes a basis for sound conservation practice. This study examined use of breeding habitat by two rainforest-breeding frog species near primary forest edge. Nine artificial breeding pools were established along each of three transects perpendicular to continuous primary forest near Manaus, Brazil. Five frog species bred in the pools over the six-month monitoring period. For the two most abundant species, patterns of habitat use were independent of proximity to forest edge. Also,Epipedobates femoralis used pools outside the forest, in secondary growth, at the same frequency as pools inside the forest.Osteocephalus taurinus did not breed outside primary forest. These results have clear implications for conservation biology: (i) buffer zones around isolated reserves, to counter possible negative edge effects on habitat, are unnecessary for these frog species, and (ii) secondary growth habitat, which is not natural breeding habitat forE. femoralis, could serve as a source of colonists for emigration into new areas and does not represent a barrier to dispersal for this species. These results argue against generalization of edge effects for different taxa.     

On the edge: habitat restoration priorities for three critically endangered bird species on Sangihe,Indonesia

Remnant forests on the small Wallacean island of Sangihe north of Sulawesi hold the entire ranges of more critically endangered (CR) bird species than any other comparable area on earth. We develop habitat association models for three of these CR species to identify critical habitat features as well as areas where habitat falls slightly short of suitability, and to determine whether another area of forest away from the largest block might be suitable as an insurance site for a translocated population. Hopes for all three species appear almost totally pinned to forest within a 13 km² area of the Sahendaruman crater, with virtually no near-suitable habitat away from this site. There is, however, little overlap in habitats between one CR species and the other two: cerulean flycatcher Eutrichomyias rowleyi is associated with mature streamside forest with full canopy cover, lianas, and mid-level growth, while Sangihe whistler Coracornis sanghirensis and Sangihe golden bulbul Hypsipetes platenae are restricted to ridgetop forest with full canopy cover and large trees. We pinpoint small areas (around 5 km²) of forest in the crater that are already suitable or can be made so with habitat management, and these are absolute priorities for conservation action. We show how habitat characteristics identified within models might be enhanced, and how features, especially certain tree species, can be used as indicators of future habitat improvement.     

Snail diversity, abundance and distribution in Arabuko Sokoke forest, Kenya

This study sought to investigate land‐snail diversity, abundance and distribution in Arabuko Sokoke forest. Sampling was done using standard timed direct search and litter sample methods. In total, 25 species and 1263 specimens were recorded. The 25 species rank Arabuko Sokoke forest as the second richest coastal forest in land snails in East Africa. The 25 species, however, are not uniformly distributed across the forest. The majority of the snails were localized with low levels of abundance. Eight species were restricted to one forest type, whereas those shared among forest types tended to concentrate in one forest type. Only five species, Gulella radius, Gulella foveolata, Gonaxis kibweziensis, Pseudoglessula biovini and Opeas gracilis, were widespread. The highest snail diversity was recorded in the mixed forest, implying that special conservation of this habitat is necessary for retention of the broadest molluscan diversity. The observation that some species rare in the mixed forest were recorded in excess from Brachystegia and Cynometra forest, further suggests that conservation of the entire A. Sokoke forest is critical for efficient molluscan conservation. Species recorded in low levels of abundance are probably declining and investigation on the snails' ecology to understand factors that influence the snails' diversity is recommended.     

Habitat use of the endangered golden‐rumped sengi Rhynchocyon chrysopygus

The endangered golden‐rumped sengi are found only in Arabuko‐Sokoke Forest with 395.4 km² of forest habitat, and perhaps in a few isolated forest and thicket fragments of total area less than 30 km² all within central coastal Kenya. Understanding its habitat use is an important requirement to develop better conservation measures for the species and its remaining forest habitat. A more reliable method for monitoring its status is also needed. We used the Bayesian occupancy modelling with camera trap data and habitat mapping to characterise the species habitat use in the Arabuko‐Sokoke Forest. The species uses 328 km² (95% CI: 289–364 km²) of Arabuko‐Sokoke Forest habitat, and its site use increases with distance from forest edge, with the highest site use in the Cynometra thicket (0.93; 95% CI: 0.82–1). Its use of the mixed forest habitat has been significantly reduced following years of logging of Afzelia quanzensis. We recommend the use of modelled occupancy, interpreted as the proportion of area used by the species, to monitor the species status. Occupancy models account for detection probability, and heterogeneity in site use and detection can be incorporated. Estimated territory sizes can be combined to obtain abundance estimates.     

Influence of Patch Factors and Connectivity on the Avifauna of Fragmented Polylepis Forest in the Ecuadorian Andes

Human‐induced alteration of habitat is a major threat to biodiversity worldwide, especially in areas of high biological diversity and endemism. Polylepis (Rosaceae) forest, a unique forest habitat in the high Andes of South America, presently occurs as small and isolated patches in grassland dominated landscapes. We examine how the avian community is likely influenced by patch characteristics (i.e., area, plant species composition) and connectivity in a landscape composed of patches of Polylepis forest surrounded by páramo grasslands in Cajas National Park in the Andes of southern Ecuador. We used generalized linear mixed models and an information‐theoretic approach to identify the most important variables probably influencing birds inhabiting 26 forest patches. Our results indicated that species richness was associated with area of a patch and floristic composition, particularly the presence of Gynoxys (Asteraceae). However, connectivity of patches probably influenced the abundance of forest and generalists species. Elsewhere, it has been proposed that effective management plans for birds using Polylepis should promote the conservation of mature Polylepis patches. Our results not only suggest this but also show that there are additional factors, such as the presence of Gynoxys plants, which will probably play a role in conservation of birds. More generally, these findings show that while easily measured attributes of the patch and landscape may provide some insights into what influences patch use by birds, knowledge of other factors, such as plant species composition, is essential for better understanding the distribution of birds in fragmented landscapes.     

Effects of topography on rainforest tree community structure and diversity in American Samoa, and implications for frugivore and nectarivore populations

Aim We investigated the spatial variation of rainforest tree community structure and composition to determine if forest structure and diversity varied as a function of topography; and in turn if this could influence patterns of habitat use by native forest birds and pteropodid bats. Location The study was undertaken on the island of Tutuila, American Samoa, located in the South Pacific Ocean. Methods All trees ≥10 cm diameter were censused in sixty 200 m² plots in ridge, slope and valley forest across the island of Tutuila. Results Forest structure varied significantly across topographical space. Ridge forest was shortest and had the highest stem densities, and valley forest was tallest with the fewest stems per unit area. Species richness was highest on ridges, and slope and valley forest were more similar in composition with each other than they were with ridge forest. Of the fifty-two tree species encountered in the plots, nine showed a statistical affiliation to one of the three topographical positions. Main conclusions We explain patterns of forest structure and diversity in the context of chronic and catastrophic disturbances. Higher stem densities in ridge forest suggested a higher degree of disturbance on ridges, and this was supported by the fact that the height/diameter ratio of the forest was lowest on ridges, which indicated wind-cropping. We hypothesize the potential effects of topographical variation and known phenological patterns on wildlife abundances. We predict that flowering episodes of ridge-affiliated, bird-visited species (particularly Syzygium inophylloides (A. Gray) C. Muell.; Myrtaceae) will concentrate honeyeater densities on ridges, and that fruiting of the tree Canarium vitiense A. Gray (Burseraceae) could localize populations of the Pacific pigeon (Ducula pacifica). Overall (i.e. net) bat foraging patterns are unlikely to be affected by either flowering or fruiting events. Most of the tree species on Tutuila are generalist in their demographic patterns, and the island is depauperate in wildlife fauna; the evolutionary and conservation implications are discussed. We conclude with the argument that conservation of vertebrate species is essential to maintain the current generalist demographic patterns of Samoan trees.     

Habitat use,density, and conservation status of the white-browed guan (Penelope jacucaca Spix, 1825)

The white-browed guan (Cracidae: Penelope jacucaca) is an endemic bird species to the Caatinga, the largest centre of dry forest in South America. This taxon was considered Vulnerable by the International Union for Conservation of Nature (IUCN) due to continued habitat loss within its distribution and intense hunting pressure that contributed to population declines. However, information on population aspects and habitat use by P. jacucaca, which is fundamental for monitoring its conservation status, is not available. We studied habitat use (analysed in a Generalized Linear Model) and population density (estimated by distance sampling) in a specific area in Northeast Brazil. Using species distribution modelling (SDM), forest cover loss data (performed in the MaxEnt program) and quantitative information about hunting, more rigorous estimates of the distribution limits, available habitat, and population declines of P. jacucaca were generated. Based on the IUCN criteria, we applied analysed data to reassess the conservation status of the white-browed guan. Local density was estimated at 13.1 individuals/km² and the estimated number of individuals removed per year due to hunting was 121.7 in the forest cover area (110.46 km²) of the Serra de Santa Catarina. Consequently, the annual removal rate of hunted individuals in the study area corresponds to approximately 11% of the population. The habitat use analysis pointed to a strong positive association with seasonally dry deciduous forest (SDDF) vegetation and with arboreal vegetation. The SDM indicated a potential distribution (climatically favourable) area of 675,823 km², and forest cover and loss calculations indicated a total of 81,307 km² of available suitable habitat in 2013. Therefore, comparing these results to the IUCN criteria, we recommend that P. jacucaca remain in the Vulnerable category.     

Early herbaceous succession along a topographical gradient on forest clear-felling sites in mountainous terrain,central Japan

Early successional patterns of herbaceous communities in forest clear-felling sites were investigated along a topographical gradient, which included ridge, slope and valley habitat types, in warm-temperate evergreen forest regions of central Japan for 5 years. Three dominant species with wind-dispersed seeds played a major role in the succession: an annual,Crassocephalum crepidioides, a biennial,Erigeron canadensis, and a perennial,Miscanthus sinensis. Pioneer herbs that have a seed-bank strategy, which are common in old field succession, were not found in the mountainous sites. The persistence of the annual or biennial dominants during the very early stages of secondary succession was different in the three topographical habitat types. In the ridge habitat,M. sinensis dominated from the first year state, andC. crepidioides andE. canadensis were less prominent.Crassocephalum crepidioides andE. canadensis became dominant as one moved down the slope. In the valley habitat,C. crepidioides dominated in the first year stage, was succeeded byE. canadensis in the second year, and thenM. sinensis gradually replaced it in later years. As all three wind-dispersed dominants simultaneously invaded in all the habitat types after clear-felling, the different successional patterns along the topographical gradient might have resulted from differences in the establishment ability and the growth rate of the three dominants depending on the three habitat types.     

Review of the conservation status of the Atlas Moth, <Emphasis Type="Italic">Attacus wardi</Emphasis> Rothschild, 1910 (Lepidoptera: Saturniidae) from Australia

The conservation status of Attacus wardi, a large iconic moth endemic to north-western Australia, is reviewed based on new data. Available evidence on the spatial distribution, critical habitat and threatening processes suggests the species qualifies as threatened according to IUCN Red List Criteria, and that its conservation status nationally should be revised from Endangered to Vulnerable. The species depends on relatively large patches of wet and dry coastal tropical monsoon forest, and it has the potential to be an important flagship species for the conservation of these ecological communities. Further studies are needed to determine minimum patch size and spatial connectivity among patches to support viable populations of the moth.     

Effects of local biotic neighbors and habitat heterogeneity on seedling survival in a spruce‐fir valley forest,northeastern China

Seedlings are vulnerable to many biotic and abiotic agents, and studying seedling dynamics helps understand mechanisms of species coexistence. In this study, the relative importance of biotic neighbors and habitat heterogeneity to seedling survival was examined by generalized linear mixed models for 33 species in a spruce‐fir valley forest in northeastern China. The results showed that the relative importance of these factors varied with species and functional groups. Conspecific negative density dependence (CNDD) was important to the survival of Abies nephrolepis and Picea koraiensis seedling, whereas phylogenetic negative density dependence (PNDD) was critical to Pinus koraiensis and Betula platyphylla, as well as functional groups of tree, deciduous, and shade‐intolerant seedlings. For shrubs and Acer ukurunduense, habitat heterogeneity was significant. Despite of the significance of CNDD, PNDD, and habitat heterogeneity on seedling survival, large proportions of the total variance were not accounted for by the studied variables, suggesting the needs to examine the influences of other factors such as pests, diseases, herbivores, forest structure, species functional traits, and microclimatic conditions on seedling survival in the future.     

Distribution, habitat characteristics and conservation requirements of a forest-dependent threatened invertebrate Lissotes latidens (Coleoptera: Lucanidae)

The distribution, habitat and conservation requirements of an endangered stag beetle, Lissotes latidens (Coleoptera: Lucanidae), in south-east Tasmania were investigated. This study trebled the known range of the species to 280 km², of which 15% constituted potential habitat. The beetle was found to inhabit a range of wet forest types including damp eucalypt forest, wet eucalypt forest, rainforest and riparian areas amongst drier forest types. Relative to other Tasmanian lucanids, L. latidens was found to occur at quite low population densities. The species had a preference for forest with a well-developed overstorey and greater than 10% ground cover of coarse woody debris (CWD). Although L. latidens is soil-dwelling throughout its life-cycle, it has a close association with CWD, occurring under logs at the interface of soil and CWD. Suitable forest habitat for L. latidens is poorly reserved, with 48% managed under clearfell, burn and sow forestry regimes; a practice that is likely to lead to the depletion of CWD over successive harvesting rotations. Recommendations are made for the conservation management of habitat utilised by L. latidens in off-reserve areas. The need for conservation strategies to incorporate the temporal dynamics of habitat important to forest-dependent threatened species is discussed.     

The Mediterranean Quercus pyrenaica oak forest: a new habitat for the Capercaillie?

We described an extension of the known distribution range of the Cantabrian Capercaillie Tetrao urogallus cantabricus into an atypical area and habitat for the species. Nine Capercaillie leks and 14 cocks were registered in Mediterranean Quercus pyrenaica forests in an area of 1,500 km², of which 4,500 forest hectares were surveyed. At present, this population represents both the southern-most distribution for Capercaillie and the only one inhabiting Mediterranean Q. pyrenaica forests, what suggests a wider adaptation of this (sub)species than previously thought. This population and its habitat need to be better studied, as well as to be considered in conservation planning for Cantabrian Capercaillie.