Personality traits differentially affect components of reproductive success in a Neotropical poison frog

Individual reproductive success has several components, including the acquisition of mating partners, offspring production, and offspring survival until adulthood. While the effects of certain personality traits-such as boldness or aggressiveness-on single components of reproductive success are well studied, we know little about the composite and multifaceted effects behavioural traits can have on all the aspects of reproductive success. Behavioural traits positively linked to one component of reproductive success might not be beneficial for other components, and these effects may differ between sexes. We investigated the influence of boldness, aggressiveness, and exploration on the number of mating partners, mating events, and offspring surviving until adulthood in males and females of the Neotropical poison frog Allobates femoralis. Behavioural traits had different-even opposite-effects on distinct components of reproductive success in both males and females. For example, males who displayed high levels of aggressiveness and exploration (or low levels of aggressiveness and exploration) managed to attract high number of mating partners, while males with low levels of boldness, low levels of aggressiveness, and high levels of exploration had the most offspring surviving until adulthood. Our results therefore suggest correlational selection favouring particular combinations of behavioural traits.

Biotic filtering by species' interactions constrains food-web variability across spatial and abiotic gradients

Despite intensive research on species dissimilarity patterns across communities (i.e. β-diversity), we still know little about their implications for variation in food-web structures. Our analyses of 50 lake and 48 forest soil communities show that, while species dissimilarity depends on environmental and spatial gradients, these effects are only weakly propagated to the networks. Moreover, our results show that species and food-web dissimilarities are consistently correlated, but that much of the variation in food-web structure across spatial, environmental, and species gradients remains unexplained. Novel food-web assembly models demonstrate the importance of biotic filtering during community assembly by (1) the availability of resources and (2) limiting similarity in species' interactions to avoid strong niche overlap and thus competitive exclusion. This reveals a strong signature of biotic filtering processes during local community assembly, which constrains the variability in structural food-web patterns across local communities despite substantial turnover in species composition.

Patterns of Bat Diversity in an Undisturbed Forest and Forest Mosaic Habitats of the Afromontane Forest Biome of Western Cameroon

Anthropogenic activities continue to degrade natural montane ecosystems globally. Bats communities are altered by these changes. We analyzed how bats are affected by human-induced habitat changes by comparing the bat species diversity and functional diversity in undisturbed forest habitats and disturbed forest habitats of the Afromontane biome of Cameroon. We recorded 244 individuals from 13 species in the undisturbed forest, while 233 individuals from 16 species were recorded in the disturbed forest. Bat diversity was higher in disturbed habitats (D = 0.84) than undisturbed habitats (D = 0.67). Jackknife 1 species richness estimator suggests 21.53 species for the disturbed forest and 19.30 in the undisturbed forest. Closed-space forager insectivorous bats made up nearly half of the species in the undisturbed forest, but this dropped to 25% in the disturbed forest, meanwhile, edge-space foragers increased in the disturbed forest. Bat community analyses by ordination revealed a distinct bat community composition between the two forest types, demonstrated as a significant difference in diversity between the two forest types. The distribution of Rousettus aegyptiacus, Myonycteris angolensis, Hipposideros cf. ruber, and Micropteropus pusillus contribute the most to the difference in bat community composition between the two forest types. Edge and open-space species were likely to benefit from additional resources provided by the disturbed area, by expanding their range and distribution. However, this may not compensate for the decline in the population of forest species caused by the loss of pristine forests, thus measures to conserve montane forest remnants should be of utmost significance.

Performance of richness estimators for invertebrate inventories in reservoirs

Biological inventories combined with the estimation of species richness represent a useful tool for the analysis of the pattern of species distribution in different regions. This study aimed to (i) comparatively evaluate the performance of non-parametric richness estimators for invertebrate inventories in reservoirs between ecoregions and (ii) to assess whether the efficiency (bias, precision and accuracy indices) of the estimators is altered when applied to sites from different ecoregions. The study was conducted in the ecoregions Central Pediplano of the Borborema Plateau (Paraíba River basin) and Northern Sertaneja Depression (Piranhas-Assu River basin), semiarid region of Brazil. Six reservoirs were selected and benthic macroinvertebrates were sampled at 141 sites distributed along the littoral zone, in 4 periods (June, September, December 2014 and March 2015). The organisms were identified to the family level, except for Chironomidae, identified to the genus level. We comparatively analyzed six non-parametric richness estimators: Jackknife 1, Jackknife 2, Chao1, Chao 2, ICE, and Bootstrap, and three performance indicators: bias, precision, and accuracy. ICE and Jackknife 2 had more stable results for total species richness, but with different performance between ecoregions for bias, precision, and accuracy. Variation in performance of the estimators may be associated with differences in species richness and frequency between ecoregions. ICE and Jackknife 2 proved to be the best estimators for biological inventories of aquatic invertebrates in reservoirs in studies comparing data from different ecoregions, due to accuracy and precision, while Bootstrap is the least indicated, given greater bias and less accuracy and precision.

Carabid beetle (Coleoptera, Carabidae) richness, diversity, and community structure in the understory of temporarily flooded and non-flooded Amazonian forests of Ecuador

Although tropical regions harbor the greatest arthropod diversity on Earth, the majority of species are taxonomically and scientifically unknown. Furthermore, how they are organized into functional communities and distributed among habitats is mostly unstudied. Here we examine species richness, diversity, and community composition of carabid beetles (Coleoptera: Carabidae) and compare them between flooded (FP) and non-flooded terra firme (TF) forests in the Yasuní area of Ecuador. The forest understory was sampled using flight intercept traps (FITs) and systematic hand collections at night in June and July 2011 and 2012, and FITs in October and November 2011. A total of 1,255 Carabidae representing 20 tribes, 54 genera, and 143 morphospecies was collected. Mean number of individuals and mean species richness did not differ significantly between FP and TF; however, numbers of Cicindelini (tiger beetles) and Pentagonicini were higher in TF forest while numbers of Lachnophorini and Scaritini were higher in FP forest. Overall, FP had significantly higher rarefied richness but extrapolation of rarefaction curves using the Chao1 nonparametric diversity estimator show that this difference may decrease with additional sampling. The inverse Simpson index was significantly higher for FP than TF forest. Nonmetric multidimensional scaling (NMDS) ordination and dissimilarity coefficient values show that FP and TF forests maintain unique assemblages with minimal overlap in community composition. Given ongoing anthropogenic pressures, particularly petroleum extraction, and those resulting from climate change, a greater understanding of the richness, diversity and community assemblages of Yasuní rainforest are needed to better conserve the fauna of this megadiverse area of Amazonia.

Effects of Forest Fragmentation on the Vertical Stratification of Neotropical Bats

Vertical stratification is a key component of the biological complexity of rainforests. Understanding community- and species-level responses to disturbance across forest strata is paramount for evidence-based conservation and management. However, even for bats, known to extensively explore multiple layers of the complex three-dimensional forest space, studies are biased towards understory-based surveys and only few assessments of vertical stratification were done in fragmented landscapes. Using both ground and canopy mist-nets, we investigated how the vertical structure of bat assemblages is influenced by forest fragmentation in the experimentally fragmented landscape of the Biological Dynamics of Forest Fragments Project, Central Amazon, Brazil. Over a three year-period, we captured 3077 individuals of 46 species in continuous forest (CF) and in 1, 10 and 100 ha forest fragments. In both CF and forest fragments, the upper forest strata sustained more diverse bat assemblages than the equivalent understory layer, and the midstory layers had significantly higher bat abundance in fragments than in CF. Artibeus lituratus and Rhinophylla pumilio exhibited significant shifts in their vertical stratification patterns between CF and fragments (e.g., R. pumilio was more associated with the upper strata in fragments than in CF). Altogether, our study suggests that fragmentation modulates the vertical stratification of bat assemblages.

Does microhabitat influence the testate amoebae communities in the Nameri National Park, northeastern India? A tropical forest perspective

The community structure of testate amoebae inhabiting different microhabitats (soil and tree-moss) within a tropical forest biome in Nameri National Park, northeastern India, was investigated. A total of 33 testate amoebae species belonging to 13 genera were identified. Species belonging to the class Lobosea constituted 73% of total testate amoebae density in the soil habitat, whereas the class Filosea constituted the most dominant forms (58%) in the moist tree-moss habitat. The relative abundance of species was higher in the tree-moss habitat compared to the soil habitats of the forest. Although multivariate analysis suggested a significant difference in assemblage patterns between the habitats, the turnover in species (i.e., beta diversity) was insignificant. Species accumulation curves (SAC) constructed using both parametric and non-parametric species richness estimators revealed that the asymptote of species richness was achieved by a low number of sample replicates in both habitats. The temperature and pH of the substratum on testate amoebae distribution patterns suggest the importance of additional background factors on testate amoebae community structure. Further studies involving more biotopes, seasons, and trophic interactions are recommended to document a complete record of testate amoebae diversity and their interactions with environmental gradients in the tropical forest biomes of northeastern India.

The effect of local land use on aerial insectivorous bats (Chiroptera) within the two dominating crop types in the Northern-Caribbean lowlands of Costa Rica

Land transformation into agricultural areas and the intensification of management practices represent two of the most devastating threats to biodiversity worldwide. Within this study, we investigated the effect of intensively managed agroecosystems on bat activity and species composition within two focal areas differing in landscape structure. We sampled bats via acoustic monitoring and insects with flight interception traps in banana and pineapple monoculture plantations and two nearby protected forested areas within the area of Sarapiquí, Costa Rica. Our results revealed that general occurrence and feeding activity of bats was higher above plantations compared to forested areas. We also recorded higher species richness at recording sites in plantations. This trend was especially strong within a fragmented landscape, with only four species recorded in forests, but 12 above pineapple plantations. Several bat species, however, occurred only once or twice above plantations, and forest specialist species such as Centronycteris centralis, Myotis riparius and Pteronotus mesoamericanus were only recorded at forest sites. Our results indicated, that mostly mobile open space and edge foraging bat species can use plantations as potential foraging habitat and might even take advantage of temporal insect outbreaks. However, forests are vital refugia for several species, including slower flying forest specialists, and thus a prerequisite to safeguard bat diversity within agricultural dominated landscapes.

Mammals recorded in isolated remnants of Atlantic Forest in southern Goiás, Brazil

Abstract: Habitat fragmentation is one of the principal causes of the decline of species worldwide, and the Brazilian Atlantic Forest and Cerrado savanna biomes are among the most severely affected by this process. While highly fragmented, remnants of Atlantic Forest can still be found within the Cerrado domain of southern Goiás, where previous studies have revealed high levels of biodiversity. To inventory the mammalian species that occur in the region, two fragments of semideciduous Atlantic Forest were sampled between 2011 and 2016, using line transect surveys and camera trapping. A total of 1016 records were obtained of 30 mammal species, of which eleven are under some threat of extinction. The species richness recorded on this study was similar to or higher than the values reported from other areas of Goiás, which reinforces the importance of the maintenance of these remnants, located in private properties, for the conservation of the region's mammals.

Monitoring fruit-feeding butterfly assemblages in two vertical strata in seasonal Atlantic Forest: temporal species turnover is lower in the canopy

To address how seasonality affects the richness and abundance of tropical insects, we compared the canopy and understorey communities of fruit-feeding butterflies in a seasonal Atlantic forest in south-eastern Brazil. Butterflies were sampled over 1 y using a standardized design with baited traps. A total of 2047 individuals in 69 species were recorded (1415 in the canopy, 632 in the understorey). Clear differences were found between canopy and understorey, with significantly higher butterfly abundances in the canopy. We observed two marked peaks of abundance and richness in both strata; one at the transition from dry to the wet seasons, and the other at the transition from wet to dry seasons. We found lower species turnover throughout the year in the canopy. We interpret this as evidence that temperature is more important than rainfall in explaining the yearly variation of abundance in vertical strata. The higher temperatures found in the canopy may allow butterflies to maintain activity in this stratum all year round, whereas the understorey is subject to colder temperatures, thus presenting a higher species turnover. These results improve our understanding of diversity gradients between evergreen and seasonal tropical forests, allowing insights into how climate and beta diversity gradients interact.

Variation in White Stork (Ciconia ciconia) diet along a climatic gradient and across rural-to-urban landscapes in North Africa

Assessing diet composition of White Storks (Ciconia ciconia) breeding under North African conditions provides key information to understanding its trophic niche for conservation purpose. Since, climate controls productivities of foraging habitats and thus food availability for predators, this study examines how Storks' diet parameters varied following a climate gradient along with rural-to-urban landscapes in north-eastern Algeria. Feeding strategies to cope with severe conditions were discussed in light of climate aridity and urbanization and how these influence reproduction, population dynamics and distribution. While invertebrate prey accounted for 94 % of ingested individuals, the biomass intake was dominated by chicken remains scavenged from rubbish dumps (67 %) and small mammals (14 %). Generalized linear models revealed that prey numbers varied significantly between climatic regions and landscapes types, but no significant differences were observed for other dietary parameters, including prey biomass. The study showed high dietary similarity between study climates and landscapes, mainly among rural and urban colonies located in semi-arid and sub-humid areas, which differed from those in suburban and arid climate. Rarefaction and extrapolation curves indicated that prey species richness in White Stork diets was expected to be higher in urban colonies located in sub-humid climate. Despite low prey species diversity in arid regions, the White Stork demonstrates a broad trophic niche, which could be due to supplementary feeding from human refuse. This study suggests that regardless of the climate or landscape, White Storks ensure a constant food intake, despite prey biomass fluctuations, by adapting their diet. Foraging in diverse habitats, including trash dumps, ensures a sufficiently balanced diet to meet nutritional requirements.

Designing Standardized and Optimized Surveys to Assess Invertebrate Biodiversity in Tropical Irrigated Rice Using Structured Inventory and Species Richness Models

Insect pest management depends on simple, rapid, and reliable sampling methods that should also be standardized and optimized. We tested structured inventory, community characterization, and sampling optimization approaches on the invertebrate fauna of Philippine irrigated rice, undisrupted by pesticides, using seven field methods and species richness models. Canopy and floodwater invertebrates were intensively and repetitively sampled from 600 quadrats (∼0.1-m(2) planar area) over dry and wet cropping seasons in one field at the International Rice Research Institute in the Philippines. In the canopy, pooled counts from D-Vac and plant dissections (PD) on the same rice hills ("absolute methodology") were compared with three other methods (i.e., FARMCOP, Blower-Vac, sweep-net), while, in the floodwater, the area collector ("absolute methodology") was compared with three other methods (i.e., FARMCOP, Blower-Vac, strainer-net). Overall, 25 and 50% of the observed richness of canopy and floodwater taxa, respectively, were caught by all four methods. Estimated inventory completeness for the canopy and floodwater averaged 82 and 98%, respectively, after all methods were pooled. To maximize observed richness, optimization results for the canopy recommended allocating the highest sampling effort to D-Vac and PD, followed by the Blower-Vac, whereas the area collector should be assigned the highest sampling effort in the floodwater, followed by the strainer-net or Blower-Vac. Our results suggest that structured inventory and species richness models are useful tools for setting optimization criteria and stopping rules for sampling crop-invertebrate assemblages based on inventory completeness and for enabling more informative biodiversity comparisons.

Low reproductive skew despite high male-biased operational sex ratio in a glass frog with paternal care

BACKGROUND

Reproductive skew, the uneven distribution of reproductive success among individuals, is a common feature of many animal populations. Several scenarios have been proposed to favour either high or low levels of reproductive skew. Particularly a male-biased operational sex ratio and the asynchronous arrival of females is expected to cause high variation in reproductive success among males. Recently it has been suggested that the type of benefits provided by males (fixed vs. dilutable) could also strongly impact individual mating patterns, and thereby affecting reproductive skew. We tested this hypothesis in Hyalinobatrachium valerioi, a Neotropical glass frog with prolonged breeding and paternal care.

RESULTS

We monitored and genetically sampled a natural population in southwestern Costa Rica during the breeding season in 2012 and performed parentage analysis of adult frogs and tadpoles to investigate individual mating frequencies, possible mating preferences, and estimate reproductive skew in males and females. We identified a polygamous mating system, where high proportions of males (69 %) and females (94 %) reproduced successfully. The variance in male mating success could largely be attributed to differences in time spent calling at the reproductive site, but not to body size or relatedness. Female H. valerioi were not choosy and mated indiscriminately with available males.

CONCLUSIONS

Our findings support the hypothesis that dilutable male benefits - such as parental care - can favour female polyandry and maintain low levels of reproductive skew among males within a population, even in the presence of direct male-male competition and a highly male-biased operational sex ratio. We hypothesize that low male reproductive skew might be a general characteristic in prolonged breeders with paternal care.

Effects of land use on bat diversity in a complex plantation–forest landscape in northeastern Brazil

In fragmented areas, the persistence of different species depends on their ability to use the surrounding matrix either as a corridor or as a foraging habitat. We assessed how species richness and abundance of Neotropical bats differ among forest fragments and rubber plantations under different management regimes. Our study site was located in a heterogeneous agricultural area in the Atlantic Forest of Bahia, northeastern Brazil. By combining mist netting and acoustic monitoring as complementary techniques, we caught 28 phyllostomid species and recorded 21 aerial insectivorous species, which either forage in open space or close to forests. Open space species were equally abundant and diverse in all land use types. In contrast, assemblages of phyllostomid and aerial insectivorous forest species differed significantly among habitats, with the highest species richness recorded in forest fragments. We identified a number of forest specialists in forest fragments, which indicates a relatively intact bat fauna. In intensively used rubber-cacao plantation, we found surprisingly high bat abundance and diversity, despite the shortage of resources for bats. Our results also indicate that patches of secondary vegetation around rubber plantations are important landscape features for bats and might contribute to the persistence of highly diverse bat assemblages. We suggest that bats do not perceive plantations as a hostile matrix, but probably use them as corridors between forest fragments and patches of secondary vegetation.

Em áreas fragmentadas, a persistência de diferentes espécies depende da habilidade delas em usar a matriz ao redor como um corredor ou hábitat de forrageio. Nós avaliamos como a riqueza de espécies e abundância de morcegos neotropicais diferem entre fragmentos de mata e seringais sob diferentes regimes de manejo. Nossa área de estudo estava localizada em uma área agrícola heterogênea na Mata Atlântica da Bahia, nordeste do Brasil. Combinando capturas em redes com monitoramento acústico como técnicas complementares, capturamos 28 espécies de morcegos filostomídeos e 21 espécies de morcegos insetívoros aéreos, que forrageiam em espaço aberto ou perto de florestas. As espécies de espaço aberto foram igualmente abundantes e diversas em todas as categorias de uso da terra. Por outro lado, comunidades de filostomídeos e insetívoros aéreos de florestas diferiram significativamente entre hábitats, com a maior riqueza de espécies tendo sido registrada em fragmentos de mata. Identificamos muitos especialistas em florestas nos fragmentos de mata, o que sugere que a fauna de morcegos ainda está relativamente intacta. Em plantações mistas de cacau e seringais intensivamente usadas, encontramos uma abundância e riqueza de morcegos surpreendentemente altas, apesar da escassez de recursos para morcegos. Nossos resultados indicam que manchas de vegetação secundária ao redor de seringais são importantes elementos da paisagem para morcegos e podem contribuir para a persistência de comunidades altamente diversas. Sugerimos que morcegos não percebem as plantações como uma matriz hostil, mas provavelmente as usam como corredores entre fragmentos de mata e manchas de vegetação secundária.

Saturniidae and Sphingidae (Lepidoptera, Bombycoidea) assemblage in Vossoroca, Tijucas do Sul, Paraná, Brazil

The richness and abundance of the assemblage of species in a community are a way to understand the patterns of diversity found around the world. This study describes the assemblages of Saturniidae and Sphingidae in an area of Montana Mixed Ombrophilous Forest, Tijucas do Sul, Paraná, Brazil, 880m, 25º50'8.93"S, 49º 02'55.20"W. Samples were collected between November 2010 and September 2011 during two nights at the twelve new moons periods with a light trap equipped with black light lamp (ultraviolet) of 46 watts between two mercury mixed-light lamps HWL 250 watts from 6:00 p.m to 06:00 a.m. The sampling effort totaled 288 hours. This sampling effort was responsible for the capture of 1235 specimens, distributed in 124 species: 858 specimens and 86 species of Saturniidae, and 377 specimens and 38 species of Sphingidae. It is noteworthy the sampling of 10 new species: one of Automerella Michener, 1949, two of Hylesia Hübner, [1820], one of Lonomia Walker, 1855 and six of Periga Walker, 1855, that will be described.

Spatiotemporal diversity, structure and trophic guilds of insect assemblages in a semi-arid Sabkha ecosystem

The current study highlights some knowledge on the diversity and structure of insect communities and trophic groups living in Sabkha Djendli (semi-arid area of Northeastern Algeria). The entomofauna was monthly sampled from March to November 2006 using pitfall traps at eight sites located at the vicinity of the Sabkha. Structural and diversity parameters (species richness, Shannon index, evenness) were measured for both insect orders and trophic guilds. The canonical correspondence analysis (CCA) was applied to determine how vegetation parameters (species richness and cover) influence spatial and seasonal fluctuations of insect assemblages. The catches totalled 434 insect individuals classified into 75 species, 62 genera, 31 families and 7 orders, of which Coleoptera and Hymenoptera were the most abundant and constant over seasons and study stations. Spring and autumn presented the highest values of diversity parameters. Individual-based Chao-1 species richness estimator indicated 126 species for the total individuals captured in the Sabkha. Based on catch abundances, the structure of functional trophic groups was predators (37.3%), saprophages (26.7%), phytophages (20.5%), polyphages (10.8%), coprophages (4.6%); whereas in terms of numbers of species, they can be classified as phytophages (40%), predators (25.3%), polyphages (13.3%), saprophages (12%), coprophages (9.3%). The CCA demonstrated that phytophages and saprophages as well as Coleoptera and Orthoptera were positively correlated with the two parameters of vegetation, especially in spring and summer. While the abundance of coprophages was positively correlated with species richness of plants, polyphage density was positively associated with vegetation cover. The insect community showed high taxonomic and functional diversity that is closely related to diversity and vegetation cover in different stations of the wetland and seasons.

Populations, pools, and peccaries: simulating the impact of ecosystem engineers on rainforest frogs

Peccary wallows and footprints are important breeding pools for rainforest frogs. We performed a resource supplementation experiment with artificial pools, simulating peccary actions, in a population of the poison frog Allobates femoralis. The population almost doubled resulting from increased local reproduction, but not from immigration. These findings demonstrate the importance of “ecosystem engineers,” such as peccaries, for other species, the frogs. Our results also indicate that human engineering may help to protect amphibian populations.

“Ecosystem engineering” describes habitat alteration by an organism that affects another organism; such nontrophic interactions between organisms are a current focus in ecological research. Our study quantifies the actual impact an ecosystem engineer can have on another species by using a previously identified model system—peccaries and rainforest frogs. In a 4-year experiment, we simulated the impact of peccaries on a population of Allobates femoralis (Dendrobatidae) by installing an array of artificial pools to mimic a forest patch modified by peccaries. The data were analyzed using a gradual before-after control-impact (gBACI) model. Following the supplementation, population size almost doubled as a result of increased autochthonous recruitment driven by a higher per-capita reproduction of males and a higher proportion of reproducing females. The effect was evenly distributed across the population. The differential response of males and females reflects the reproductive behavior of A. femoralis, as only the males use the aquatic sites for tadpole deposition. Our study shows that management and conservation must consider nontrophic relationships and that human “ecosystem engineering” can play a vital role in efforts against the “global amphibian decline.”

Is there any empirical support for biodiversity offset policy?

Biodiversity offsets are seen as a policy mechanism to balance development and conservation goals. Many offset schemes employ habitat restoration in one area to recreate biodiversity value that is destroyed elsewhere, assuming that recovery is timely and predictable. Recent research has challenged these assumptions on the grounds that restoration implies long time delays and a low certainty of success. To investigate these assertions, and to assess the strength of empirical support for offset policy, we used a meta-analytic approach to analyze data from 108 comparative studies of secondary growth (SG) and old-growth (OG) habitat (a total of 1228 SG sites and 716 OG reference sites). We extracted species checklists and calculated standardized response ratios for species richness, Fisher's alpha, Sorenson similarity, and Morisita-Horn similarity. We modeled diversity change with habitat age using generalized linear models and multi-model averaging, correcting for a number of potential explanatory variables. We tested whether (1) diversity of passively and actively restored habitat converges to OG values over time, (2) active restoration significantly accelerates this process, and (3) current offset policies are appropriate to the predicted uncertainties and time lags associated with restoration. The results indicate that in the best case, species richness converges to OG reference values within a century, species similarity (Sorenson) takes about twice as long, and assemblage composition (Morisita-Horn) up to an order of magnitude longer (hundreds to thousands of years). Active restoration significantly accelerates the process for all indices, but the inherently large time lags, uncertainty, and risk of restoration failure require offset ratios that far exceed what is currently applied in practice. Restoration offset policy therefore leads to a net loss of biodiversity, and represents an inappropriate use of the otherwise valuable tool of ecosystem restoration.

Skipper Richness (Hesperiidae) Along Elevational Gradients in Brazilian Atlantic Forest

Hesperiidae are claimed to be a group of elusive butterflies that need major effort for sampling, thus being frequently omitted from tropical butterfly surveys. As no studies have associated species richness patterns of butterflies with environmental gradients of high altitudes in Brazil, we surveyed Hesperiidae ensembles in Serra do Mar along elevational transects (900-1,800 m above sea level) on three mountains. Transects were sampled 11-12 times on each mountain to evaluate how local species richness is influenced by mountain region, vegetation type, and elevational zones. Patterns were also analyzed for the subfamilies, and after disregarding species that exhibit hilltopping behavior. Species richness was evaluated by the observed richness, Jacknife2 estimator and Chao 1 estimator standardized by sample coverage. Overall, 155 species were collected, but extrapolation algorithms suggest a regional richness of about 220 species. Species richness was far higher in forest than in early successional vegetation or grassland. Richness decreased with elevation, and was higher on Anhangava mountain compared with the two others. Patterns were similar between observed and extrapolated Jacknife2 richness, but vegetation type and mountain richness became altered using sample coverage standardization. Hilltopping species were more easily detected than species that do not show this behavior; however, their inclusion did neither affect estimated richness nor modify the shape of the species accumulation curve. This is the first contribution to systematically study highland butterflies in southern Brazil where all records above 1,200 m are altitudinal extensions of the known geographical ranges of skipper species in the region.

Species richness and host specificity among caterpillar ensembles on shrubs in the Andes of Southern Ecuador

Caterpillar ensembles were sampled on 16 species of shrubs from the family Asteraceae and the genus Piper (Piperaceae) in open and forest habitats in the Andean montane forest zone of southern Ecuador between August 2007 and May 2009. Trophic affiliations of caterpillars to the host plants were confirmed in feeding trials. Overall, species richness of herbivorous caterpillars was high (191 species across all plants), but varied strongly between ensembles associated with different plant species (2-96 lepidopteran species per shrub species). Ensembles on Piper species were characterized by low effective species numbers and high dominance of one or two species of the Geometridae genus Eois Hübner. Low species number and high dominance were also found on latex-bearing Erato polymnioides, whereas ensembles on two other Asteraceae species were far more diverse and less strongly shaped by a few dominant species. The observed diversity patterns fit well to the concept that anti-herbivore defenses of plants are the major factors regulating associated insect ensembles. Local abundance and geographic range of host plants appear to have less influence. Lepidopteran species feeding on Asteraceae were found to be more generalistic than those feeding on Piper species. We conclude that caterpillar ensembles on most, but not all, studied plant species are defined by a small number of dominant species, which usually are narrow host specialists. This pattern was more distinct on Piper shrubs in forest understory, whereas Asteraceae in disturbed habitats had more open caterpillar ensembles.

Climate, habitat, and species interactions at different scales determine the structure of a Neotropical bat community

Climate, habitat, and species interactions are factors that control community properties (e.g., species richness, abundance) across various spatial scales. Usually, researchers study how a few properties are affected by one factor in isolation and at one scale. Hence, there are few multi-scale studies testing how multiple controlling factors simultaneously affect community properties at different scales. We ask whether climate, habitat structure, or insect resources at each of three spatial scales explains most of the variation in six community properties and which theory best explains the distribution of selected community properties across a rainfall gradient. We studied a Neotropical insectivorous bat ensemble in the Isthmus of Panama with acoustic monitoring techniques. Using climatological data, habitat surveys, and insect captures in a hierarchical sampling design we determined how much variation of the community properties was explained by the three factors employing two approaches for variance partitioning. Our results revealed that most of the variation in species richness, total abundance, and feeding activity occurred at the smallest spatial scale and was explained by habitat structure. In contrast, climate at large scales explained most of the variation in individual species' abundances. Although each species had an idiosyncratic response to the gradient, species richness peaked at intermediate levels of precipitation, whereas total abundance was very similar across sites, suggesting density compensation. All community properties responded in a different manner to the factor and scale under consideration.

Biodiversity assessment in incomplete inventories: leaf litter ant communities in several types of Bornean rain forest

Biodiversity assessment of tropical taxa is hampered by their tremendous richness, which leads to large numbers of singletons and incomplete inventories in survey studies. Species estimators can be used for assessment of alpha diversity, but calculation of beta diversity is hampered by pseudo-turnover of species in undersampled plots. To assess the impact of unseen species, we investigated different methods, including an unbiased estimator of Shannon beta diversity that was compared to biased calculations. We studied alpha and beta diversity of a diverse ground ant assemblage from the Southeast Asian island of Borneo in different types of tropical forest: diperocarp forest, alluvial forest, limestone forest and heath forests. Forests varied in plant composition, geology, flooding regimes and other environmental parameters. We tested whether forest types differed in species composition and if species turnover was a function of the distance between plots at different spatial scales. As pseudo-turnover may bias beta diversity we hypothesized a large effect of unseen species reducing beta diversity. We sampled 206 ant species (25% singletons) from ten subfamilies and 55 genera. Diversity partitioning among the four forest types revealed that whereas alpha species richness and alpha Shannon diversity were significantly smaller than expected, beta-diversity for both measurements was significantly higher than expected by chance. This result was confirmed when we used the unbiased estimation of Shannon diversity: while alpha diversity was much higher, beta diversity differed only slightly from biased calculations. Beta diversity as measured with the Chao-Sørensen or Morisita-Horn Index correlated with distance between transects and between sample points, indicating a distance decay of similarity between communities. We conclude that habitat heterogeneity has a high influence on ant diversity and species turnover in tropical sites and that unseen species may have only little impact on calculation of Shannon beta diversity when sampling effort has been high.

Species diversity of bats along an altitudinal gradient on Mount Mulanje, southern Malawi

A climate model, based on effects of water availability and temperature, was recently proposed to explain global variation in bat species richness along altitudinal gradients. Yet such studies are sparse in the tropics and near-absent in Africa. Here we present results from an altitudinal study of bat diversity from Mount Mulanje, Malawi. Using ground nets, canopy nets and harp traps, we sampled eight sites across three habitat zones from 630 m to 2010 m asl. We assessed the influence of climatic, geographic and biotic variables on measures of estimated species richness, Fisher's α, and an unbiased index of compositional turnover. We recorded 723 individuals and 30 species along the gradient, revealing a ‘low plateau’ pattern in estimated species richness, peaking at 1220 m, which is congruent with the global climate model. Measures of local habitat structure significantly explained a large degree of variation in species richness and compositional turnover between sites. Fisher's α was further significantly correlated to mean annual relative humidity, suggesting a background climatic influence.

Predator diversity and abundance provide little support for the enemies hypothesis in forests of high tree diversity

Predatory arthropods can exert strong top-down control on ecosystem functions. However, despite extensive theory and experimental manipulations of predator diversity, our knowledge about relationships between plant and predator diversity--and thus information on the relevance of experimental findings--for species-rich, natural ecosystems is limited. We studied activity abundance and species richness of epigeic spiders in a highly diverse forest ecosystem in subtropical China across 27 forest stands which formed a gradient in tree diversity of 25-69 species per plot. The enemies hypothesis predicts higher predator abundance and diversity, and concomitantly more effective top-down control of food webs, with increasing plant diversity. However, in our study, activity abundance and observed species richness of spiders decreased with increasing tree species richness. There was only a weak, non-significant relationship with tree richness when spider richness was rarefied, i.e. corrected for different total abundances of spiders. Only foraging guild richness (i.e. the diversity of hunting modes) of spiders was positively related to tree species richness. Plant species richness in the herb layer had no significant effects on spiders. Our results thus provide little support for the enemies hypothesis--derived from studies in less diverse ecosystems--of a positive relationship between predator and plant diversity. Our findings for an important group of generalist predators question whether stronger top-down control of food webs can be expected in the more plant diverse stands of our forest ecosystem. Biotic interactions could play important roles in mediating the observed relationships between spider and plant diversity, but further testing is required for a more detailed mechanistic understanding. Our findings have implications for evaluating the way in which theoretical predictions and experimental findings of functional predator effects apply to species-rich forest ecosystems, in which trophic interactions are often considered to be of crucial importance for the maintenance of high plant diversity.

Lepidopterofauna (Papilionoidea e Hesperioidea) do Parque Estadual do Chandless e arredores, Acre, Brasil

Tendo em vista a ausência de inventários lepidopterológicos no Estado do Acre e sua escassez no bioma amazônico brasileiro, o presente estudo objetivou contribuir para a construção da lista de Hesperioidea e Papilionoidea presentes no Parque Estadual do Chandless, localizado em uma região de difícil acesso e sem infra-estrutura para pesquisa científica. Durante 14 dias foram realizadas coletas com redes entomológicas, armadilhas e técnica de Ahrenholz em diferentes ambientes que caracterizam o parque e seus arredores. Foram identificadas ao total 482 espécies, nenhuma delas presente em listas vermelhas de espécies ameaçadas. É esperado um número significativamente maior de espécies após a adição de novas coletas em outras estações do ano, visto a estimativa Jacknife 1 não atingir sua assíntota, ou mesmo em comparação a inventários em áreas próximas que listam, após um intenso esforço amostral, até cerca de 1700 espécies.