Oecologia

Immune defenses may vary across environments due to differences in life history or abiotic and biotic characteristics, but few studies have compared the strength of immune responses across broad geographical gradients. Here we investigated how bacteria killing ability (BKA), a measure of constitutive innate immune function, varies among populations of tree swallows (Tachycineta bicolor) inhabiting different environments. We hypothesized that populations living in unpredictable environments, which also have shorter breeding seasons and thus fewer opportunities to renest in the event of reproductive failure, would invest in reproduction at the expense of immunity. To test this hypothesis, we measured BKA and monitored reproductive activity in four populations located across most of the breeding range of tree swallows, in Tennessee, New York, Wyoming and Alaska. Consistent with our predictions, BKA was lowest in Alaska and Wyoming and highest in Tennessee. In most populations BKA was also lower during incubation than during nestling provisioning, and lower in males than in females. These results suggest that the high reproductive investment seen in populations experiencing more unpredictable breeding conditions may come at a cost to immune function. While reduced immune investment could increase susceptibility to parasites, this potential cost is likely offset by lower parasite pressure in these environments, limiting the need for maintaining strong constitutive innate defenses like BKA.

Early environmental conditions can have long-lasting effects on survival and reproductive fitness. Using a 23 year-long monitoring data set of captive mouse lemur's life history traits, we tested a relationship between maternal allocation to offspring (N = 1365) and their adulthood survival. Maternal characteristics such as age or body condition did not affect allocation to offspring whatever the litter size (1 to 3). Although birth mass depended on size and composition of the litters, mouse lemur survival was highly correlated with body mass acquired after weaning in both sexes, through potential sibling competition. Moreover, female's reproductive success correlated with this body mass and was consistently associated with increased longevity. These findings suggest the presence of a silver spoon effect under constant captive conditions. However, cumulative effects of genetic and adulthood social conditions strongly interact to affect adult survival. Deaths related to intra- or inter-sexes aggressive social interactions may outweigh effect of early environment and therefore minimize the silver-spoon effect on captive mouse lemur's survival. However, having a high body mass after weaning appeared to be a determinant factor in individual survival for mouse lemurs.

Morphological variation in insects can indicate responses to habitat change and land use intensification, with potential consequences for trophic interactions. In insect host-parasitoid systems, host body is often a key determinant of offspring development and emergence success, as well as parasitoid host-selection behavior. Yet, most studies in agricultural landscapes have focused on size variation in crop-associated insects (i.e.: pests, pollinators and enemies), leaving those relying on non-crop resources largely unexplored. Here, we investigated how agroenvironmental contexts and trophic resource availability influence puparial size in Protocalliphora sialia (Diptera: Calliphoridae), an obligate hematophagous ectoparasite of Tree Swallow (Tachycineta bicolor) nestlings. We further tested whether puparial size affects emergence probability and risk of parasitoidism by Nasonia spp. (Hymenoptera: Pteromalidae) jewel wasps. Using 1,513 P. sialia puparia from 88 nests within a nest-box monitoring system spanning a 10,200-km^2 east-west intensification gradient in southern Quebec, Canada, we evaluated how agrointensive contexts, avian host availability, and ectoparasite densities influence puparial size, parasitoidism risk, and emergence success. The agricultural context appears to shape puparial size through survival biases and/or altered growth rates. In agroextensive contexts (i.e.: pastures, forages with high tree cover), where Protocalliphora are more numerous, P. sialia puparia were smaller and exhibited greater size variation. Conversely, in agrointensive environments (maize and soybeans monocultures with higher doses of pesticides), where Protocalliphora are fewer, small individuals were underrepresented, suggesting a selective mortality in P. sialia population. However, puparial size explained less than 10% of the variation in emergence or parasitism, likely reflecting consistently high parasitic pressure from Nasonia wasps, which infested 50-90% of puparia, depending on site and year. Our findings highlight the importance of selective mortality in structuring trait distributions and modulating multi-trophic interactions in human-modified landscapes.

Beta diversity is a fundamental component of regional biodiversity that accumulates from compositional differences between local species assemblages. Although beta diversity is increasingly applied across spatial scales, its scale dependence remains incompletely synthesized, particularly concerning variation in spatial scale used to define alpha diversity (grain size). Using tree community data from Barro Colorado Island, we find that both additive and multiplicative beta diversity are consistently higher for unequal than equal grain divisions across different spatial extents and numbers of grains. These results can be explained by Jensen's inequality based on the concave-down relationship of alpha diversity with area that in turn increases beta diversity through the scaling relationship between alpha and gamma diversity. Combined with our additional analysis showing that this prediction is robust to more general models of species richness, including species--area and species--sampling-effort curves, these results reveal a previously unrecognized, predictable range of beta diversity variation.

Temporal stability of plant populations is a key determinant of species coexistence and ecosystem functioning, yet its trait-based explanation has remained largely aboveground. Whether root functional traits contribute to long-term population stability remains poorly understood, despite roots mediating water and nutrient acquisition. We combined 17 years of vegetation monitoring from 150 temperate grassland plots across three regions in Germany with root functional trait data for 72 common grassland species. Temporal stability was computed as coefficient of variation (CV), with lower CV indicating higher stability. We tested whether root traits predict stability, and specifically which belowground dimensions from resource acquisition/conservation or soil exploration dominate, and whether differences in land use intensity modifies these relationships. Root traits were stronger and more consistent predictors of temporal stability than the classical aboveground traits specific leaf area (SLA) and leaf dry matter content (LDMC). Higher average root diameter (AD), root hair incidence (RHI), specific root length (SRL), and root tissue density (RTD) were generally associated with higher temporal stability, although the strength of these relationships varied among regions. Land use modified selected trait and stability relationships, with the strongest shifts occurring along the mowing gradient. Increasing mowing strengthened the associations of higher RHI and RTD with temporal stability, whereas the associations of AD and root N shifted towards lower stability. Our results identify belowground functional traits as an important missing component of trait-based temporal stability research and advance our understanding of the functional strategies underlying population temporal stability in managed semi-natural grasslands.

Fruit resource availability can influence the local abundance of avian frugivores through bottom-up regulation, but whether greater resource availability translates into higher visitation rates to fruiting trees remains poorly understood. Greater fruit availability could increase visitation by supporting larger frugivore populations, or reduce visitation to individual trees if increases in frugivore abundance are not proportionate to those in fruit availability or if frugivores distribute their foraging effort. Understanding these relationships can provide insights into the relative role of abundance and trait-based mechanisms in structuring plant-frugivore communities. We compared fruit availability, avian frugivore abundance, and frugivore visitation rates on fruiting trees across two protected wet tropical forest sites: Anamalai Tiger Reserve in the Western Ghats and Namdapha Tiger Reserve in the Eastern Himalaya. Specifically, we quantified the availability of bird-consumed fruits across one-ha patches, estimated local abundances of major frugivore groups, and tested whether visitation rates on individual fruiting trees were related to frugivore abundance, body mass, and degree of frugivory. We found that small-seeded fruit availability was significantly higher in Anamalai than in Namdapha. Local abundances of several relatively small-bodied frugivore groups, including bulbuls, barbets, fairy-bluebirds, and mynas, were also higher in Anamalai. However, visitation rates of several frugivore groups on individual fruiting trees were higher in Namdapha. Visitation rates across all avian frugivore species were associated with frugivore abundances only in Anamalai, and not associated with body mass or degree of frugivory in either site. Thus, although greater fruit availability was likely associated with higher frugivore abundance, this increase in abundance did not consistently translate into higher visitation rates at individual fruiting trees, which provides some support for the resource dilution hypothesis. Our results highlight the importance of considering fruit resource availability and frugivore abundance when examining variation in tropical plant-frugivore interactions.

Streambank erosion degrades both terrestrial and aquatic ecosystems, and riparian buffers are among the most widely used tools to control it. Yet most of what is known about how riparian vegetation controls erosion comes from one or two-species systems, which overlook the diversity of riparian communities and species interactions (competition and facilitation) that may shape the root systems that bind soil. We used a streambank mesocosm experiment to test whether plant species richness alters root traits, and whether root traits and species interactions reduce erosion. We established 85 mesocosms ranging from unvegetated controls to six-species polycultures, measured root biomass, length, volume, and diameter, quantified species interactions with relative yield totals (RYT), and measured erosion rate with a jet erosion test. Vegetated mesocosms eroded significantly less than unvegetated controls (t = 4.05, p = 0.023). Richness did not affect most root traits, although mean root diameter decreased as richness increased ({beta} = -0.0225, p = 0.047). RYT ranged from competition (RYT < 1) to facilitation (RYT >1), yet neither interactions nor any root trait was directly associated with erosion rate. However, RYT was negatively associated with soil moisture ({beta} = -0.196, p = 0.010). Piecewise structural equation models showed that erosion was best explained by a pathway linking species presence, root length, and soil moisture (AIC = 39.27; Fisher's C = 11.27, df = 12, p = 0.506). Panicum virgatum increased root length, whereas Lolium multiflorum and Echinochloa crus-galli reduced it; longer roots were associated with drier soil (standardized {beta} = -0.31, p = 0.005), and wetter soils eroded more slowly (standardized {beta} = -0.39, p < 0.001). Which species were present mattered more than how many, and plants were linked to erosion through soil moisture rather than root traits alone. Species selection for riparian buffers may need to consider effects on soil moisture as well as rooting extent, particularly as droughts followed by intense storms become more common under a changing climate.

Defended prey are often thought to rely on conspicuous warning signals to distinguish themselves from undefended prey, facilitating predator learning and avoidance. Yet many chemically defended organisms are inconspicuous and difficult to distinguish from palatable prey, raising a fundamental question: how do predators avoid defended prey when prey themselves provide little or no reliable signals of defense? We tested whether host plants can function as indirect indicators of prey defense using Carolina wrens (Thryothorus ludovicianus), chemically defended Eumaeus atala larvae, undefended Galleria mellonella larvae, and two distinct plant species. Defended and undefended prey were experimentally made to appear visually identical, forcing predators to rely on host-plant associations as the only available source of information. Wrens rapidly altered both search behavior and attack decisions according to plant identity. Mechanistic attack models incorporating predator discrimination between defended and undefended prey were strongly favored when plants were present, with defended prey experiencing substantially lower attack risk than undefended prey. When plants were removed, support for discrimination weakened and attacks on both prey types increased. Spatial autocorrelation of host plants further shaped predator behavior, with strongly clustered plants hosting defended prey receiving disproportionately fewer visits. Together, these results suggest host plants can function as ecologically meaningful cues of prey defense, influencing both predator search patterns and attack decisions. More broadly, our findings suggest warning systems may extend beyond prey phenotype alone, and that ecological context (including host-plant identity and spatial structure) may contribute to the evolution and maintenance of aposematism.

Diurnal ectotherms in hot and dry ecosystems face an acquisition trade-off between maximizing collective energy intake and minimizing individual exposure time. We employed optimal foraging and thermoregulation models to examine the surface foraging and thermoregulatory strategies of Pogonomyrmex barbatus foragers in response to habitat warming in a tropical deciduous forest. Foraging activity was evaluated using field-based thermal performance curves (fTPCs) for individual foraging speed and collective foraging success. Thermoregulation was assessed through indices of thermal unsuitability, as well as thermoregulatory effectiveness and exploitation. Our results show that afternoon conditions were significantly hotter and drier than those in the morning. Furthermore, the decoupling of fTPCs was dynamic; while the optimal temperature (Topt) for individual foraging speed remained stable at 44 degrees C, the Topt for collective foraging success shifted from 35 degrees C in the morning to 41 degrees C in the afternoon. This shift in foraging strategy, driven by stressful afternoon conditions, was reflected in a transition of the thermoregulatory strategy. Specifically, the probability of foraging activity decreased as thermal unsuitability increased, with a lower baseline in the afternoon. The thermoregulatory exploitation dropped from 94% in the morning to 63% in the afternoon. Based on thermoregulatory effectiveness, foragers transitioned from an active thermoregulatory strategy in the morning to a thermoconformist strategy in the afternoon while foraging on the surface. So, the observed colonies optimized the balance between individual foraging speed and collective foraging success through a thermoregulatory strategy that was primarily spatial in the morning and strictly temporal in the afternoon. A comparison with historical data from the same site reveals a 40% contraction in the total daily foraging window since 2013.

Litter invertebrates mediate a substantial proportion of decomposition and nutrient cycling in terrestrial ecosystems, yet how moisture availability structures their communities remains poorly understood. We propose that moisture availability could shape litter faunal communities through two alternate pathways: (1) a productivity effect: greater productivity and detrital inputs in wetter forests should increase litter-faunal abundance, (2) a trait effect: phylogenetic differences in water balance should filter communities according to taxon-specific moisture tolerances. We tested these expectations across 100 forest sites spanning a moisture gradient in south-eastern Australia, from dry sclerophyll forest to cool temperate rainforest. Measuring 11 focal invertebrate taxa, total litter-faunal abundance increased threefold across the moisture gradient, from 400,000 individuals per hectare of dry forest to 1.2 million individuals per hectare of rainforest - consistent with greater resource availability in wetter and more productive habitats. However, this overall abundance trend masked pronounced variation in community composition across habitat types. While moisture-sensitive crustaceans and myriapods (particularly Isopoda and Chilopoda) were concentrated in rainforest litter, two groups of hexapods (Blattodea and Embioptera) were most abundant in dry forest litter and declined sharply toward rainforest habitat. These contrasting responses indicate that dry forests do not simply represent depauperate versions of wet-forest communities but harbour their own distinct and abundant litter invertebrate assemblages. Thus, moisture structures litter faunal communities via both proposed mechanisms: (1) a productivity effect and (2) a trait filtering effect. Given that moisture fundamentally structures litter faunal communities, shifts in forest moisture regimes under climate change may substantially alter detritivore communities, with consequences for decomposition processes and nutrient cycling globally.

Ground-nesting wild bees require suitable soil conditions for their below-ground development and overwintering life stages. Understanding how soil translocation and disturbance affect individuals and the following generations of bees is important for identifying conservation measures for ground-nesting wild bees. We investigated the effects of soil translocation and disturbance on the ground-nesting solitary spring mining bee Colletes cunicularius. In a replicated controlled design, we compared the effects of soil translocation with different degrees of disturbance on the number of surviving bees and the emergence time. We found that soil translocation and disturbance reduced bee survival but did not result in complete mortality, with some individuals surviving even under severe soil disturbance. There was no evidence that soil disturbance affected the timing of spring emergence, suggesting that disturbance is unlikely to alter the timing of nest construction and, consequently, the production of the next generation. Our results indicate that translocating soil containing overwintering bees could be a promising conservation measure to compensate for habitat loss caused by land conversion.

Arboreal camera trapping is an emerging remote sensing tool for building plant-frugivore interaction networks with enormous potential to provide new insights into seed dispersal as an eco-evolutionary process. Interaction data derived from camera trap videos broadly falls into two categories: visitation, indicating the presence of an animal in a tree, and intake, indicating true fruit consumption. These linked approximations of seed dispersal may or may not provide distinct sets of information, shaping our understanding of network dynamics, yet the extent to which emergent network structure depends on variable choice is unknown. To address this gap, we deployed camera traps in the canopy of 21 plant species in the Costa Rican tropical dry forest, an endangered biome with sparse community-wide plant-frugivore interaction data. Our objectives were: 1) Quantify plant-frugivore network structure in the tropical dry forest via network, group, and species-level metrics; and 2) Compare metrics between visitation and intake networks. We find strong structural patterns of low connectance, low nestedness, high modularity, and low niche overlap that differ significantly from null expectations in the same direction in both networks. The visitation network exhibited significantly greater modularity & species degree than the intake network, while the intake network exhibited significantly greater plant niche overlap than the visitation network. These findings suggest that the likelihood of consuming fruit on camera differs across species, which may have downstream consequences on other emerging metric estimations. Researchers seeking to build quantitative plant-frugivore networks should therefore consider visitation and intake variables in concert when relying on camera trap data. This work provides foundational plant-frugivore interaction data for a critically endangered biome and enhances our understanding of camera trapping as a remote sensing tool in frugivory and seed dispersal research.

Understanding spatial and temporal variation in community composition is central to protecting and monitoring biodiversity. Similarity in the composition of two communities decreases along spatial and temporal gradients, a relationship known as distance decay. Comparing distance-decay relationships across taxonomic, functional, and bioclimatic facets of diversity provides a means of interrogating niche-based versus neutral influences on community assembly. Furthermore, the context in which these facets yield overlapping or complementary information about global change impacts remains poorly understood. In this study, we examined spatiotemporal distance-decay relationships for taxonomic, functional, and bioclimatic facets of alpine plant diversity leveraging elevation gradients on five peaks in the White Mountains, California, USA, sampled at 3-4 time points between 2007 and 2024. Using multivariate Bayesian beta regression models, we estimated the slopes of elevation distance decay over multiple surveys and across taxonomic, functional and bioclimatic diversity to understand how spatial distance-decay relationships are changing through time and across different facets of diversity. We found strong spatial distance decay of taxonomic similarity across all peaks, with the highest elevation peak showing the strongest decay. Functional and bioclimatic similarities decayed more weakly than taxonomic similarity, suggesting environmental filtering shapes trait and niche distributions. Critically, spatial decay patterns showed no temporal signal across facets of diversity, indicating community stasis rather than biotic homogenization or differentiation. This study adds further evidence that xeric alpine plant communities are resisting climate change impacts through time.

Associations among species are hypothesized to become fewer and more specialized toward the tropics. However, evidence for the latitudinal specialization gradient (LSG) remains mixed and restricted to plant-animal and host-parasite models, with increasing recognition that our understanding of LSG is often complicated by differences in species richness and sampling effects. Here, we tested whether specialization between foliar fungal endophytes - fungi that live within plant leaves - and their plant hosts increased toward the tropics by surveying 1,539 plants that spanned a 55-degree latitudinal gradient in Central and North America. Contrary to expectations, endophytes and plants formed a greater number of associations that were more evenly distributed toward tropical latitudes and were thus less specialized, even after accounting for differences in endophyte and plant community structure. Endophyte-plant communities were most specialized where evaporative demand and plant richness were low, and where water availability and primary productivity were high. Our findings show a reversed LSG where the specialization between endophytes and plants decreased toward the tropics and provides evidence that many species of endophytes can coexist even when there is high overlap in their host niches.

Exotic species can reshape native communities, in the extreme, to local extirpation. Before that, natives may adjust where and when they use the landscape, in ways that allow coexistence and may be the earliest sign of trouble. Distinguishing coexistence built on such adjustment from one built on pre-existing niche differences requires comparing a native where the invader is absent with the same native where it is present, across sites at different invasion stages. Using eight years (2018-2026) of camera-trap data from 103 stations across Uruguay (154,590 camera-nights), we asked how the invasive axis deer (Axis axis) affects the space and time use of two native cervids: the forest-dwelling brown brocket (Subulo gouazoubira) and the grassland-restricted pampas deer (Ozotoceros bezoarticus). Activity-overlap, directional-avoidance, hierarchical activity, and two-species occupancy analyses showed sharply divergent dyads. A. axis and S. gouazoubira shared forest yet segregated in space and along the understory stratum the brocket requires and the invader avoids, and shifted their diel activity by context; understory cover fell with A. axis abundance, consistent with habitat modification. For A. axis and O. bezoarticus, segregation was intrinsic, opposite diel niches and habitats, with no support for a detectable shift in pampas deer behavior. The only behavioral signal was asymmetric: the invader, rather than the native, appeared to adjust, though few shared sites warrant caution. The same invader thus drives different mechanisms, but coexistence is provisional: A. axis is still expanding, far from equilibrium, so these shifts read best as early warning signals.

1. Group foraging reduces the risks associated with foraging: larger groups dilute individual predation risk, allow group members to share the costs of vigilance, and provide a social structure for exchanging information about predators. The benefits of shared social information over simple safety in numbers should depend on the relationships among group members. Consequently, group composition should affect the selection of risky and safe habitats in social species. 2. We asked whether relationships among elk (Cervus canadensis) group members moving together influence their selection of risky habitats more than grouping alone. We tested three hypotheses. The familiarity hypothesis predicts that elk with close social ties are most likely to select risky habitats together. The inclusive fitness hypothesis predicts that the closest genetic relatives are most likely to select risky habitats together. The dilution hypothesis predicts that familiarity and genetic relationships do not influence habitat selection, with all group foraging benefits derived from proximity to others. 3. We used integrated Step Selection Analysis to test whether the identity of the closest group members influenced habitat selection. We tested whether the relationship of the nearest elk--either genetic or social--incentivized selection of risky habitat more than proximity to the nearest elk. 4. Group foraging clearly reduced risk, with elk more likely to select risky habitat when near others. Elk were also more likely to select risky habitats when near closer relatives, albeit with considerable variation among individuals. However, familiarity had a large and consistent effect: elk were far more likely to select risky habitats when near socially familiar group members. 5. Our results suggest that information shared within foraging groups, especially between socially familiar individuals, may lower the risks associated with habitat selection. Similarly, the benefits of reliable social information for reducing risk likely incentivizes the formation of stronger social ties within foraging groups. This positive feedback between social familiarity and habitat selection could thereby increase access to profitable habitats that are otherwise too risky, cementing what we term the social information landscape as a key driver of movement and habitat selection.

Backgrounds and Aims: Partitioning of biomass to various organs is fundamental to growth and survival strategies of plant species, with broad-scale ecological implications from competition to carbon flux of ecosystems. Although partitioning patterns have been studied extensively in embryophytes, little is known about the variation and evolutionary drivers of biomass partitioning strategies in marine plants, such as seaweeds, that form marine forests analogous to those on land. Methods: We measured developmental variation in standing organ biomass for 18 species of kelp and used a previously published dataset on land plants to draw comparisons between kelps and embryophytes, with respect to developmental allometry, interspecific allometry and the relationship between the two measures. Key results: We report that kelps exhibit large variation in partitioning patterns, with some species differing by more than an order of magnitude in holdfast and stipe investment when controlling for size. The range of biomass partitioning patterns exhibited by kelps includes values not found among embryophytes, highlighting differences in selective pressures on land and in the ocean. However, as previously demonstrated, empirical values of interspecific scaling curves closely match those of land plants. This suggests that despite fundamentally different physical constraints, evolutionary scaling has converged on nearly identical interspecific exponents. We further demonstrate that allometric covariation exists between support organs (stipe and holdfast), highlighting the importance of physical forces in driving functional diversification of marine plants and supporting the notion that covariation of traits is a hallmark of botanical structure and function. Conclusions: The results of our study illuminate the variation and evolutionary patterns of biomass partitioning in marine primary producers. Moreover, these results highlight that universal evolutionary scaling relationships can emerge from fundamentally divergent developmental and biomechanical pathways.

Colony defence is critical for the survival of wild honeybees but presents a challenge for local populations and beekeepers. Apis mellifera scutellata is an important pollinator in its native range, a large area of Southern and Eastern Africa 1, but is reputed for its explosive temperament. Here, we present data demonstrating that this behaviour is only exhibited by a small fraction of colonies, while others are relatively docile. This sheds new light on this subspecies and on its likely evolutionary trajectory. We further characterize the different elements of this defensive response and compare them to that of A. m. carnica and A. m. mellifera. We show that each subspecies invests differently in the two steps of the behavioural sequence (alert and attack). Furthermore, our results suggest that the task of attacking is carried out by specialized workers in carnica, but not in the other subspecies tested, highlighting subtle differences in colony organization across subspecies. Finally, we discovered that defenders from A. m. scutellata and scutellata-hybrid colonies can locate a target that was stung up to 2 h and 3 h earlier, respectively, whereas European bees could only do so for 30 min. This long-term marking could confer an advantage against returning predators with few weak points, such as honey badgers and humans wearing protective clothing. Overall, we offer a fresh perspective on this controversial but important subspecies of honeybees, with implications for both future studies and daily management.

Fallen fleshy fruits are temporary resource patches that can support diverse but transient invertebrate assemblages, yet their successional dynamics remain poorly documented in tropical landscapes modified by human activity. We examined heterotrophic succession on fallen ripe guava fruits, Psidium guajava, in a tropical grove in Barasat, West Bengal, India. Eight fruits were placed in exposed and shaded microhabitats and followed from fresh to degraded stages over 22 days. Invertebrates were recorded using repeated scan sampling, and daily observations for each fruit were analysed for taxon richness, Shannon diversity, total peak relative abundance, community composition and indicator taxa associated with decomposition stages. Across 141 daily fruit observations, we recorded 44 invertebrate taxa. Taxon richness, Shannon diversity and total peak relative abundance were highest during fresh and pre rotten stages and declined sharply during post rotten and degraded stages. Decomposition stage was the strongest predictor of alpha diversity, resource use intensity and community composition, whereas differences between exposed and shaded microhabitats were weaker. Indicator taxa showed clear successional replacement: fresh fruits were associated with drosophilid and tephritid flies; fresh and pre rotten fruits with nitidulid beetles and ants; and later stages with collembolans, staphylinids, blattodeans and other taxa associated with detrital stages. Ants, especially Pheidole sp., were conspicuous resource users and showed guarding, hoarding, predation and pulp or seed removal behaviour, although their effects on other taxa remain observational. These results show that fallen guava fruits function as ephemeral heterotrophic resource patches, supporting rapid invertebrate turnover at fine temporal scales in a tropical grove.

A longstanding question in evolution is if similar morphologies shared by distantly related organisms facing similar environmental pressures belie similar functions. The carnivorous pitcher form has evolved in three distinct plant lineages and encompasses a suite of convergent morphological traits, providing a natural experiment to test hypothesized links between morphology and function. Multiple pitcher plant species possess fenestrations (i.e., small windows) that let light pass through the pitcher leaf. While research on one species, Nepenthes aristolochioides, demonstrates that fenestrations manipulate light to create false exits and increase prey capture, whether this convergent morphology serves this convergent function in other pitcher species remains unresolved. We explored the function of fenestrations in two additional species of pitcher plants, Nepenthes klossii and Cephalotus follicularis, where the morphology and function of fenestration were previously unexplored. We inspected micromorphology of pitcher structure, conducted an insect bioassay with live plants to test for links between morphology and function, and quantified traits associated with light manipulation from herbarium specimens. Both species exhibited fenestration and related pitcher morphology similar to N. aristolochioides. Yet our experiments did not reveal a significant effect of light passing through fenestrations on fly capture for these two species. Key differences between these species and the previously investigated species may be the presence of wax crystals and the absence of viscoelastic fluid. While future studies may uncover weak to moderate light manipulation function not detected in our study, our data do not support convergent function in these distantly related, morphologically similar species.