Deterministic and stochastic processes are of great importance in influencing the composition of communities. Here, we tested if deterministic and stochastic processes have the same force of influence on functional traits of tiger moth communities. Specifically, we hypothesised that the functional traits of the tribe Arctiini would be more strongly influenced by stochastic processes (associated with spatial variables), given that these moths are primarily diet and habitat generalists within a highly diverse clade. They also exhibit high morphological trait dissimilarity and are capable of occupying a wide range of vegetation habitats. On the other hand, we hypothesised that the functional traits of the tribe Lithosiini would be more influenced by deterministic processes (associated with environmental variables), given that these moths are primarily diet and habitat specialist moths and tend to occur in more specific vegetation types. In agreement with our hypotheses, the functional traits of Arctiini species were better explained by variables related to stochasticity, while the functional traits of Lithosiini were explained by deterministic processes only. Thus, the processes shaping moth distributions across communities may vary according to species’ functional traits and interspecific relationships.

Tropical urban estuaries are understudied, where ecosystem health is often considered through a temperate lens. Here, we use stable isotopes and other biogeochemical parameters to begin to address the hypothesis that the biogeochemical drivers of water column chemistry in tropical urban estuaries are qualitatively different from those in temperate systems. We measured salinity, dissolved oxygen, temperature, turbidity, dissolved nutrients, enterococcus concentrations, and suspended particulate stable isotope and nitrogen (N) and carbon concentrations every two weeks for three years in the San Juan Bay Estuary, Puerto Rico. Enterococcus concentrations exceeded acceptable limits (35 CFU 100 ml-1) in all but three water samples measured in a densely populated channel within the estuary that receives urban runoff and untreated sewage (n = 207). The δ15N values were lowest in this channel, highest in the portion of the estuary with open exchange with the sea, and negatively correlated with dissolved inorganic nitrogen concentrations. This observation, is contrary to current paradigms that were developed in temperate estuaries. The source of the low δ15N values is unknown, but consistent with observations in the sediment and consistent with high rates of N fixation. In addition to the need for a basic understanding of the biogeochemical and ecological processes involved, these data serve as a baseline to compare the effects of restoration efforts and climate change.

Dry ecosystems are critical to the global carbon cycle. Seasonally dry tropical ecosystems as a whole are botanically megadiverse, yet we have little understanding of how diversity impacts aboveground carbon, which is particularly noticeable for insular Asia. Across 133 vegetation plots on the seasonally dry tropical island of Flores, we used spatially explicit models to determine how land use impacts aboveground carbon stocks and whether this is dependent upon multidimensional diversity. Carbon is greatest in primary forests and least in agricultural landscapes. However, we find that land use interacts with phylogenetic and species diversity to shape carbon stocks. Across almost all models, quadratic effects of diversity were better predictors of carbon, indicating that whilst the initial build-up of diversity increases carbon, greater diversity causes carbon decline. Results suggest that future conservation plans will be needed to balance carbon storage with multidimensional diversity, which may offer distinct benefits for ecosystem resilience and services.

Reservoir construction causes marked changes in hydrological, physical and chemical conditions, with rapid effects on aquatic communities. The initial filling phase, characterised by abrupt changes over days to weeks and the onset of vertical stratification, is particularly critical, yet its effects on planktonic ciliate communities remain poorly understood. Here, we combined high-frequency sampling with a two-strata design (surface and bottom) to investigate how the initial filling, and consequent vertical stratification, of a tropical reservoir affect the density, biomass and taxonomic groups composition of the planktonic ciliates community. We observed pronounced temporal and spatial changes, with physicochemical differences between strata and filling phases. We observed that the ciliate community responded to these changes with consistently higher density and biomass at the surface and in the middle of the filling period. Linear mixed-effects and generalised additive models supported our findings, with significant temporal variation in all attributes, with trajectories over the filling period characterised by an initial increase followed by a decline, and by marked shifts among ciliate groups that indicate a clear successional pattern. Our results suggest that the surface strata of the reservoir work as a dynamic and productive environment, whereas the bottom strata remain limiting for ciliate development, mainly due to lower oxygen concentrations. By providing one of the few high-resolution assessments of planktonic ciliates during reservoir filling, integrating vertical structure, temporal dynamics and taxonomic succession, this study extends the trophic-surge perspective to microbial consumers and highlights the value of ciliates as bioindicators during dam construction and early reservoir operation.

Lepidopteran stemborers are among the most destructive pests of maize, sorghum, and sugarcane in Africa. Yet, data on their species composition and host range in Rwanda remain limited. This study provides the first comprehensive assessment of stemborer diversity, seasonal dynamics, and altitudinal distribution across eastern (low altitude), central (mid-altitude), and northern (high altitude) Rwanda. Surveys were conducted during both the rainy (maize growing) and dry seasons of 2023–2024, targeting infested maize fields and surrounding wild vegetation. A total of 2691 stemborer individuals were recovered from nine host plants, with 1474 (54.8%) from wild and fodder vegetation and 1217 (45.2%) from maize plantations. Species richness was highest in the mid-altitude zone, while overall abundance peaked at low altitudes. Busseola fusca was the most abundant in the high-altitude zone, Chilo partellus in the low altitude, and Sesamia spp. was concentrated in the mid-altitude. Seasonal variation significantly influenced population dynamic, with the highest abundance (1251; 46.4%) recorded during the dry season. Notably, Pennisetum purpureum (Napier grass) hosted 1156 (42.9%) of all specimens, highlighting its role as a key refugium during maize off-seasons. These findings underscore the ecological importance of wild vegetation in sustaining stemborer populations and suggest that wild vegetation, altitudinal, and seasonal factors must be considered in designing integrated lepidopteran stemborer pest management strategies.

Figs (Ficus spp.) are widely considered keystone resources in tropical ecosystems, yet mechanisms underlying their importance to primates are rarely assessed. We tested five hypotheses explaining the importance of figs for mantled howlers (Alouatta palliata) using a 10-year phenological dataset from southeastern Mexico. We monitored 57 trees representing figs and five other dietary species weekly from 2012 to 2021. The asynchrony hypothesis predicted lower intraspecific synchrony in figs, but we found no differences between figs and other species. The keystone hypothesis was strongly supported: this genus reduced weeks below critical thresholds by 59.5%, rescuing the community from scarcity in 72 weeks (14.7% of monitoring). During these events, figs contributed 20% of resources despite representing one-sixth of monitored taxa. The bet-hedging hypothesis predicted lower interannual variance in fig fruiting, but figs showed significantly higher variance than most species. The complementarity hypothesis predicted negative correlations between fig and non-fig phenology, yet we found positive correlations. The multiple cropping hypothesis predicted more fruiting cycles in figs than other species, but frequencies were equivalent (2.16 vs 2.13 cycles/year). Figs function as a keystone resource for mantled howlers not through unique phenological patterns but through reliable provisioning during critical scarcity periods, preventing resource bottlenecks that could otherwise limit the persistence of howler populations.

Leaf litter in headwater streams serves as an important energy source for the aquatic food web. However, the timing, magnitude, and source dynamics of leaf litter inputs into tropical montane streams have received less attention. Here we present an 8-year study of leaf litter inputs from two tropical montane first-order headwater streams in the Luquillo Experimental Forest, Puerto Rico that include a prolonged drought period and major hurricanes. Leaf litter was collected across different landscape sources such as canopy and riparian inputs, and litter transported from upstream. The different sources of leaf litter were compared to environmental variables (precipitation, wind, solar radiation, and temperature) to identify potential drivers of inputs to streams and exports. Leaf litter from upstream was the greatest contributor (50–95%) and can vary with storms and droughts. Transitions between dry and wet periods led to pulses of leaf litter in both streams. Increasing precipitation, solar radiation, and wind led to increased leaf litter inputs but varied across sources. The variable responses across sources to climatic events suggest that the timing and magnitude of litter inputs to headwater streams may be specific by source. Moreover, the results underscore the value in considering the forest cover of the watershed landscape in its entirety when quantifying organic matter inputs as they depend on upstream conditions that go beyond the immediate reach-adjacent riparian zone.

The vegetation in many African national parks is undergoing notable changes due to disturbances at various spatial and temporal scales. Understanding the responses of species can help with predicting future impacts of human-induced disturbance-related drivers on the vegetation in Mole National Park. This study aimed to examine how woody species react to disturbance-related factors in five vegetation types (woodland, savannah forest, riparian forest, swamp forest, and boval vegetation) across the park. We tested the hypothesis that the effects of wildfires, herbivory activities, invasive alien plant species, erosion, and bare ground on the tree community structure differ among the five vegetation types, as individual species respond differently to these drivers. Our results showed that the impact of fire regimes, invasive alien plant species, herbivory, erosion, and bare ground accounted for 59% of the low abundance of the individuals observed in the riparian and swamp forest vegetation types. Similar disturbances, especially fire regimes and invasive alien plants, also contributed to the presence of rarer species such as Afraegle paniculata and Isoberlinia doka in the woodland and boval vegetation types. However, the dominance and wide distribution of Detarium microcarpum, Combretum adenogonium, Terminalia avicennioides, and Icacina senegalensis in these two vegetation types suggest their resistance to these disturbance-related factors, particularly fire regimes, through the use of adaptive fire-cued mechanisms. We conclude that increased disturbances may lead to the extinction of many rarer species, while the few resistant and resilient species are likely to experience a decline in their populations in such resource-limited environments.

All animals, through their behaviours, modify their habitats. However, except for ecosystem engineers, for most species we know little about these modifications and their ecological consequences. Here, we assessed whether mantled howler monkeys in Mexico, through group defecations under sleeping trees, create microhabitats in the understory through increased dung beetle and rodent activity. In defecation and control sites, we sampled dung beetles with pitfall traps and rodents with camera traps. We also used experimental stations to measure dung removal and secondary seed dispersal by dung beetles and seed predation/removal by rodents. Supporting our hypothesis, we found that defecation sites had higher abundance of beetles and prolonged rodent visitation after one day and higher seed predation/removal after seven days. However, we found no differences in dung removal or secondary seed dispersal by dung beetles between defecation and control sites. Finally, contrary to our prediction, defecation sites had fewer photo records of rodents than control sites. Overall, our study shows that monkey group defecations under sleeping trees can create short-term microhabitat heterogeneity, although not necessarily in the expected direction. The next step will be to determine whether such effects can have longer-term consequences for forest ecology, such as promoting plant species coexistence.

This study aimed to examine the response of land snails to five land-use types (protected forest, unprotected forest, cocoa plantation, teak plantation, and fallow) in the Lamto Reserve and its surrounding rural area. Snails were sampled monthly and for one year, using a combination of direct search and litter sieving techniques on 20 plots (5 plots of 400m2/land-use type). A total of 5471 individuals belonging to 53 species and 10 families were sampled. Abundance peaked in the protected forest and was lowest in rural land-use types, while species richness was highest in forests and the cacao plantation and lowest in fallow. However, the Shannon index and species composition showed no significant variation, in contrast to evenness. Eighteen of the 53 recorded species were associated with land-use types, mostly in the protected forest. Snail abundance was mainly influenced by canopy cover, soil calcium, and sand content, with a marked seasonal effect peaking during the rainy season. Canopy cover and litter depth emerged as the main determinants of diversity indices. Land-use changes significantly impact snail communities, underscoring the need for balanced conservation land management in tropical ecosystems.

Surveying nocturnal arboreal mammals in the tropics is challenging. Traditional methods are poorly suited to observing cryptic, often small-bodied mammals in the canopy. Subsequently, little is known about their ecology and behaviour despite the important functional roles they play within tropical forest ecosystems. We describe a method for observing behaviour from an elevated platform using thermal binoculars, evaluating the method against four criteria relating to species detected, field of view, potential disturbance, and richness of data. We surveyed for 205 h across 18 nights, recording 14 nocturnal arboreal mammal species with 126 independent events. Nocturnal arboreal species accounted for 61% of all observations. We found that elevating the observer aided the detectability of mammals by lessening the observation distance and the amount of foliage between the observer and the target. The observer also had a three-dimensional field of view and could follow mammals as they moved around the area. Thermal imaging emits no light source that will reveal the observer’s presence, and so the risk of influencing mammal behaviour is likely to be reduced. This method shows potential to help fill behavioural knowledge gaps in nocturnal arboreal mammals in the tropics. Furthermore, the costs of the approach would make it accessible to many researchers.

Landscape changes due to forest loss and fragmentation challenges the maintenance of biodiversity. In general, these spatial processes affect the resource availability, species interactions, and microclimatic conditions – shifts that impair ecological assemblages’ diversity. Through beta diversity, it is possible to understand how landscape changes affect assemblages’ temporal variations. This study focused on analysing the effect of landscape composition and configuration on the assemblage heterogeneity of Cetoniinae beetles under a spatial and temporal lens. Beetles were sampled monthly from May to October 2022 using traps baited with fermented fruit in landscapes that comprised a gradient of anthropogenic disturbance. To estimate landscape spatial shifts, the amount of forest and agricultural lands, the amount of edges, and landscape diversity were estimated in the studied sites. A total of 649 individuals of six genera and nine species were collected. Spatially, more diverse landscapes had a higher temporal species turnover compared to less diverse landscapes; landscapes with higher amounts of edges maintained more abundant Cetoniinae assemblages compared to those with lower amounts of edges. Two distinct clusters according to the Cetoniinae assemblage were structured. This work is one of the first studies carried out with Cetoniinae in the Neotropical region. Our results present a first step to disentangle how spatial and temporal factors in a tropical fragmented landscape affect the patterns of Cetoniinae assemblages.

Bait traps are a standard technique for studies of tropical butterfly community ecology and long-term assessment of population trends, with butterflies often regarded as biodiversity indicators. Fermented banana is the standard bait, but carrion baits, which may attract more individuals, species, and taxonomic groups, are also commonly used. However, the influence of carrion bait type on the butterfly sample is unknown. Here, we assessed the efficiency of three sources of carrion bait (shrimp, snapper, and tilapia), with banana as a comparison, in sampling butterflies in a west Ecuadorian premontane rainforest. Different carrion baits resulted in minor variation in sampled abundance and species diversity and minimal variation in species composition. All carrion baits recorded up to four times higher butterfly abundance than banana. Species composition was virtually identical among carrion baits, but only about half as similar to that sampled with banana. Choosing a consistent carrion bait for a monitoring scheme will facilitate temporal and spatial comparisons, but, given the minimal differences among carrion baits, practical considerations such as accessibility or cost may help determine bait choice. Finally, in agreement with other researchers, we support the simultaneous use of carrion and fruit baits to significantly increase sampled taxonomic diversity.

Biodiversity is a key driver of ecosystem functioning, largely due to niche complementarity among species. Litter decomposition plays a crucial role in the cycling of matter, which supports other processes such as soil formation, primary productivity, and carbon storage. We examined whether litter mixtures with higher taxonomic diversity decompose more rapidly than those with lower diversity, and to what extent arthropods contribute to this pattern. We established a natural microcosm experiment within a remnant of Atlantic rainforest in Southeastern Brazil, where we set litterbags of equal weight (10 g), but varying numbers of litter species (from one to 16). Species identities were randomly assigned across replicates to control for species-specific effects. The litterbags remained in the field for 189 days, after which we extracted arthropods using Berlese funnels operated continuously for seven days. Richer litter mixtures decomposed faster and supported a higher abundance of arthropods. Previous studies reported varied results, which depended on specific species in the mixture and synergistic or antagonistic effects. Such variability is often attributed to site-specific conditions, experimental design, and the identity of litter species used. Importantly, our experimental design minimised the influence of particularly responsive species in high-diversity treatments while preserving natural field conditions. Higher abundance of arthropods in richer mixtures likely played a central role in accelerating decomposition. Soil fauna typically enhances decomposition through physical fragmentation, which increases surface area and alters structural properties of the litter. This mechanical disruption facilitates microbial colonisation and mineralisation by fungi and bacteria, thereby promoting more efficient decomposition.

Only less than 2% of bat species use modified leaves as roosts called ‘tents’. Few systematic surveys have been conducted to assess the abundance, diversity and density of tent-roosting bats and their tents. We present new records of plants used as tents and a new record of a tent-roosting bat species resulting from the first-ever bat tent survey conducted in the northern Atlantic Forest of Brazil. After two field visits for active search in the Murici Ecological Station (MES) in Alagoas state, 45 tents were found, with a density of three tents per hectare in a covered area of 3,340 m2 (0.34 ha). Three umbrella-type tents housed one individual of Artibeus obscurus each, all constructed on leaves of the hemi-epiphyte Philodendron ornatum (Araceae). This is the first record of A. obscurus using and probably modifying leaves to use them as a roost. One boat-type tent harboured two Vampyressa pusilla on the hemi-epiphyte Philodendron fragantissimum, representing the northernmost records of tents in the Atlantic Forest and for northeastern Brazil. The MES represents an important area for protecting tent-roosting bats in northeast Brazil, given the extensive historical deforestation and habitat loss within the Pernambuco Endemism Center and the northern Atlantic Forest.

Selective logging is a prevalent practice in tropical forests that can impact wildlife health. Here, we investigate the effects of selective logging on the body condition of the Lowland tapir (Tapirus terrestris) in Jamari National Forest, Brazilian Amazonia. We apply a visual assessment protocol for scoring tapir body condition, based on camera trap images obtained in logged and unlogged areas. Tapirs from both areas presented high body condition scores (average of 4.2 on a scale of 1 to 5), and there were no significant differences in scores between areas (mean score unlogged = 4.2, sd = 0.54; mean score logged = 4.3, sd = 0.56), suggesting that logging does not affect tapir body condition. However, our results apply to the short term. Further research is necessary to understand the long-term implications of logging on the tapir.

Seasonal variation in temperature and precipitation affects food availability for organisms. Tropical bats are trophically diverse, representing many feeding guilds, and can represent about half of mammalian diversity in tropical areas. Stable isotope analysis of nitrogen (δ15N) in animal tissues permits inference on phenology of diet and trophic level through repeated sampling of a single tissue over time or by simultaneous sampling of multiple tissues that vary in isotopic turnover rate. The goal of our study was to use multi-tissue stable isotope analysis to investigate the phenology of diet (i.e., trophic-level switching) in bats. We sampled tissues of museum specimens from five tropical bat species representing different trophic guilds (insectivores, frugivores) and movement capacities (wide-ranging, narrow-ranging). We measured δ15N in three metabolically latent (hair, skin, bone) and four active (heart, kidney, spleen, liver) tissues and generated mathematical model predictions of expected δ15N values of these tissues based on their foraging guild. Specifically, we predicted that species with more sedentary movement patterns (i.e., narrow-ranging species) would have high among-tissue variation in δ15N and species that move further and more often (i.e., wide-ranging) would have less δ15N variation among tissues. Our results supported our predictions and suggest that the phenology of diet is detectable by multi-tissue isotope analysis using δ15N.

Octocorals of the genus Heliopora are known to be abundant and to be capable of building large mono-specific stands on Indo-Pacific coral reefs. They have a calcium carbonate skeleton and although they are zooxanthellate, they have been observed to resist threats that have a negative impact on other reef-building corals, such as long periods of elevated seawater temperatures, and population outbreaks of predators, such as corallivorous Acanthaster crown-of-thorns sea stars. On the other hand, Heliopora corals can be harmed by aggressive competitors for space, but how they attack Heliopora is not well documented. Here, we illustrate examples from Indonesia in which Heliopora corals are overgrown and overtopped by corals of Porites rus and the genus Montipora. The nature of these interactions is discussed, and a hypothetical future scenario is presented in which Heliopora may become a more successful competitor and a more common reef coral species than it is today.