The project, called Who Eats Whom, was launched in 2019 on iNaturalist, one of the world’s largest citizen science platforms, which holds hundreds of millions of geolocated, time-stamped photographs of wildlife. The idea is elegantly simple. Volunteers who happen to photograph an animal in the act of feeding, whether a glaucous-winged gull tearing into a starfish, a giraffe browsing a duiker-berry tree, or an American crocodile snatching an invasive lionfish, can submit their images to the project. Each feeding event generates two linked observations, one for the consumer and one for the consumed, and the iNaturalist community collectively proposes and refines the taxonomic identifications for both. Metadata tags then bind the pair together as a documented trophic interaction, complete with photographic evidence.

The scale of participation has grown far beyond what the founders initially promoted. Since its launch, Who Eats Whom has amassed nearly 14,000 observations of feeding interactions contributed by close to 2,000 observers spread across more than 100 countries. Remarkably, most of these contributions have come from volunteers who discovered the project on their own while browsing the iNaturalist database, rather than through targeted recruitment campaigns. This organic growth suggests that the photographic bycatch of ordinary biodiversity observation, images of feeding that people capture incidentally while documenting species, represents a vast and largely untapped reservoir of ecological information covering a geographic and taxonomic breadth that no targeted field study could ever achieve.

In 2025, the team began building a web application to transform this raw trove of observations into a usable scientific resource, releasing it in early 2026. The platform draws on the iNaturalist Application Programming Interface to collate data in real time, meaning the database grows dynamically as new observations pour in. The site restricts itself to so-called research-grade observations, those in which the iNaturalist community has reached high agreement on the identity of both species involved. The developers are careful to note that research-grade status confirms the taxonomy but does not independently verify that feeding actually occurred in every image, a distinction that matters for rigorous use. Even so, the filtering yields a network that, as of January 2026, connects 1,863 species through 1,607 unique feeding interactions, a figure the team expects to climb toward hundreds of thousands as iNaturalist itself continues its rapid expansion.

The technical architecture of the platform is designed around accessibility and scalability. Users type in a species of interest and can ask either what it eats or what eats it, then explore the results through five complementary visualization modes. A grid view displays the underlying photographs, putting faces, so to speak, on every interaction. A graph view and a network view render the data as directed networks in which nodes represent species and arrowheads point toward the consumer, with line widths encoding how frequently an interaction has been documented. A map view plots interactions geographically, while a global view renders the entire database as one sprawling interactive food web. Every search can also be exported as a CSV file, lowering the barrier for researchers who want to fold the data into their own analyses.

For ecologists, the applications are numerous. The database can supply basic natural history information about the dietary needs or natural enemies of poorly studied species, a gap that remains enormous given that the feeding ecology of most organisms on Earth has never been formally documented. It can surface rare or previously unrecorded interactions, flag highly connected prey species that may serve as keystone food sources, and expose taxa or regions where data are so sparse that targeted fieldwork is warranted. Conservation biologists could use it to model the potential trophic ripple effects of an invasive species or to search for candidate biological control agents. The temporal and spatial metadata attached to each observation open further avenues, from tracking how diets shift across seasons and life stages, a field known as feeding phenology and ontogeny, to cataloging which interactions currently exist so that they can be protected before they vanish.

The researchers are candid about the limitations inherent in unstructured citizen science data. Because observations are not collected under controlled sampling protocols, the database inevitably mirrors the biases of the people behind the cameras. Large, conspicuous, charismatic, and terrestrial organisms are overrepresented, while small, cryptic, aquatic, and nocturnal interactions remain comparatively rare. Who Eats Whom is therefore best understood as a living natural history archive rather than a representative sample of the planet’s trophic relationships. Even in well-studied and relatively simple ecosystems, food webs are extraordinarily complex, and constructing complete ones has proven stubbornly difficult. Yet incomplete food webs still carry genuine scientific value, particularly when analyzed with quantitative network methods, and centralized repositories like this one create the capacity to merge photographic evidence with complementary techniques such as DNA metabarcoding, producing more robust and multi-layered pictures of ecological networks than any single method could deliver alone.

Beyond the laboratory, the project has been deliberately shaped as a tool for education and public engagement. Food webs are a staple of secondary school science curricula, and questions about what animals eat resonate far beyond academia, whether a gardener wondering which plants best support native pollinators or a hiker curious about the predator lurking at the top of a local trail. The team is co-developing guidelines with the iNaturalist community for classifying the different types of feeding interactions, distinguishing parasitism from herbivory, nectar feeding from scavenging, and plans future updates including improved search queries, richer network visualizations, a dedicated R package for programmatic access, and a community vetting system for data quality. With an organized corps of volunteers reviewing submissions in real time and the sophisticated iNaturalist identification machinery working underneath, the database is effectively self-improving.

There is a philosophical dimension to the project as well. When John Muir wrote that trying to pick out anything by itself reveals it hitched to everything else in the universe, he was describing precisely the relational view of nature that Who Eats Whom seeks to operationalize. The wonder inspired by organisms such as Maculinea caterpillars, which mimic the pheromones and even the sounds of ant queens to be adopted into colonies and fed by worker ants, lies not in their existence as isolated species but in the astonishing specificity of their relationships. By shifting attention from species in isolation to the diversity of connections among them, the project offers a corrective to a reductionist habit in Western science and makes those connections visible and tangible to anyone with a web browser.

What began as a modest effort to harvest the accidental bycatch of wildlife photography has matured into the first global food web built from verifiable citizen science images, a complement to existing interaction databases such as Global Biotic Interactions and a citizen science project in its own right. Its creators anticipate that letting the public visualize and manipulate the tangled web of who consumes whom could deepen appreciation for the interconnected natural world and, perhaps, strengthen the resolve to conserve it. In the meantime, every hiker, gardener, and beachcomber with a smartphone holds the potential to add another thread to the map, one photograph of lunch in the wild at a time.

Subject of Research: A citizen science-derived global database of feeding interactions between species built from iNaturalist photographs

Article Title: Who Eats Whom? A global food web derived from citizen science

Article References: Allf, B. C., Mallavarapu, A., Kikuchi, D. W., Vasudeva, N., & Dunn, R. R. (2026). Who Eats Whom? A global food web derived from citizen science. PLOS Biology, 24(9), e3003988. https://doi.org/10.1371/journal.pbio.3003988

Image Credits: AI Generated

DOI: 10.1371/journal.pbio.3003988

Keywords: citizen science, food webs, iNaturalist, species interactions, trophic ecology, biodiversity, ecological networks, predation, natural history, conservation, data visualization, public engagement

The research, led by Philip T. Butterill and Sam Finnie with colleagues at the New Guinea Binatang Research Centre, focused on forest patches near Madang town in Madang Province. Over eight months, from August 2010 to March 2011, the team searched the foliage of 32 locally common woody plant species, spanning basal eudicots, rosids, asterids and even a single gymnosperm. Each species received identical sampling effort, roughly 78 hours of foliage searching per plant species, spread evenly across sites and seasons. The result was a conservative haul of about 8,150 galled plant modules, from which the researchers reared 820 individual parasitoids representing 102 species.

The scale of the sampling matters, because questions about host specificity in tropical food webs have long been hampered by patchy data. Using rarefaction and extrapolation methods, the team estimated that their sampling captured roughly 95 percent of the parasitoid community associated with the targeted hosts and galls. Completing the species accumulation curve, they calculate, could add another 10 to 35 parasitoid species, but would require nearly double the effort. That level of coverage lends unusual confidence to the network statistics that followed.

What those statistics revealed was striking. By the traditional definition, 79 percent of the 102 parasitoid species were specialists, attacking only a single host gall species. Even after removing rare singletons and doubletons, which can inflate apparent specialisation, two-thirds of the remaining species remained monophagous. A complementary index of specialisation, d-prime, told the same story: 61 percent of parasitoid species scored above the interpretive midpoint of 0.5, and the mean value was significantly higher. At the level of the whole network, specialisation reached an H2-prime of 0.89, far above the average of 0.65 reported in a major synthesis of host–parasitoid networks. The community was dominated by chalcid wasps, which accounted for 92.4 percent of individuals and 83.3 percent of species, with the family Eulophidae alone making up nearly half of all species.

This degree of specialisation challenges a persistent hypothesis in tropical ecology. Because specialist herbivores on rare plant species occur at low densities, some researchers have argued that parasitoids in diverse tropical forests must be generalists to make a living. Studies of leaf-mining insects in tropical forests have indeed documented predominantly generalist parasitoid communities. But the gall-parasitoid web of Madang shows the opposite pattern, and the authors point to several interlocking mechanisms. In temperate regions, most gallers are uni- or bivoltine, producing at most one or two synchronous generations per year, which creates intense competition among parasitoids for brief resource pulses. In the aseasonal tropics, overlapping generations mean that only a small fraction of galls are at a suitable developmental stage at any moment, favouring specialists whose life cycles are precisely synchronised with a single host over opportunistic generalists chasing sporadic late-stage galls.

Taxonomy adds another layer. The dominant gall formers in the tropics are cecidomyiid midges, which are almost exclusively host specialists, whereas the cynipid gall wasps that dominate northern temperate gall communities, tied closely to oak trees, tend to be more flexible. Quercus is largely absent from the tropics, shifting the galler pool toward lineages whose parasitoids are repeatedly reported as highly host-specific. The parasitoid specialisation in the Papua New Guinean web closely mirrors the extreme host fidelity of the gallers themselves, suggesting a reciprocal pattern in which each trophic level locks the others into place. The authors tentatively propose a latitudinal gradient in gall-parasitoid specialisation, intensifying toward the equator, while acknowledging that a definitive test will require studies in transitional forests where cynipids and cecidomyiids co-occur.

Specialisation has cascading consequences for indirect interactions. When parasitoids attack multiple hosts, they can mediate apparent competition, in which an increase in one herbivore species boosts shared enemies and suppresses another. The researchers quantified this potential for all pairs of the 42 gall species from which parasitoids emerged. Of 861 possible heterospecific pairs, only 7 percent had any non-zero potential, and even those values were low, averaging 0.069. Sixteen gall species shared no parasitoids at all with any other species. In contrast, the mean potential for intraspecific competition, each host’s capacity to fuel its own enemies, was 0.76. In this web, gallers are far more likely to be regulated by their own specialist parasitoids than to be caught in cross-species enemy-mediated conflict, exactly as the team hypothesised.

The second major finding concerns gall appearance. Galls vary enormously in size, structure and colour, and the researchers scored each of 78 gall morphospecies for apparency, a composite of size and visual similarity to the host plant organ, based on standardised inspection of photographs and specimens. Using negative binomial generalised linear models with host gall abundance as a covariate, they tested which traits best predicted the number of parasitoid species reared from each gall type. Abundance was the strongest single predictor, as expected. But among morphological traits, apparency and gall-former taxon were retained in the final model, which explained just over 50 percent of the deviance. More conspicuous galls, those that stand out from the plant by virtue of large size or contrasting colour, hosted consistently richer parasitoid assemblages. Notably, apparency outperformed gall size alone in model comparisons, indicating that the composite visual signal carries information that raw dimensions do not.

Why would showy galls attract more enemies? One possibility is that parasitoids rely heavily on visual cues when locating hosts, perhaps especially because some gall-forming insects can suppress the volatile chemical signals that plants normally emit when attacked. Another provocative idea is the aposematic gall hypothesis, which suggests that chemically defended, brightly coloured galls warn off predators. Yet evidence from caterpillar-parasitoid systems shows that aposematism can reduce predation while increasing parasitism, consistent with a safe haven hypothesis in which well-defended hosts offer ideal conditions for parasitoids. The same logic may extend to galls. The authors are careful to stress that their apparency scores reflect human vision, not parasitoid spectral sensitivity, and that ultraviolet reflectance and natural canopy lighting were not measured, so the pattern remains correlative rather than a demonstration of cause.

An intriguing secondary result emerged when the analysis was restricted to the cecidomyiids, the dominant gall taxon. Within this single lineage, plant module, whether the gall occurred on leaves, stems or other organs, became a significant predictor of parasitoid richness alongside apparency, even though module effects were masked in the multi-taxon analysis. This suggests that microhabitat within the plant shapes parasitoid recruitment primarily within host lineages, while lineage identity and overall conspicuousness dominate comparisons across the full community. The broader implications are sobering for anyone estimating tropical biodiversity: extrapolating the observed ratio of roughly three parasitoid species per plant species to the more than 500 woody species recorded in a nearby forest dynamics plot, the authors estimate that parasitoid diversity in this forest could exceed 1,000 species, a hidden multitudes figure that underscores how much of tropical food web complexity still awaits discovery.

Subject of Research: Specialisation and gall apparency in a tropical plant–gall–parasitoid food web

Article Title: Gall Apparency Drives Parasitoid Richness in a Highly Specialised Gall‐Parasitoid Food Web From a Tropical Rainforest

Article References: Butterill, P. T., Finnie, S., Sam, K., Fayle, T. M., Freiberga, I., & Novotny, V. (2026). Gall Apparency Drives Parasitoid Richness in a Highly Specialised Gall‐Parasitoid Food Web From a Tropical Rainforest. Ecology and Evolution, 16(10), Article e74375. https://doi.org/10.1002/ece3.74375

Image Credits: AI Generated

DOI: 10.1002/ece3.74375

Keywords: food webs, parasitoids, gall-forming insects, tropical rainforest, Papua New Guinea, host specialisation, apparent competition, gall morphology, Cecidomyiidae, tri-trophic interactions, network ecology, biodiversity

The research, conducted by Colton Herzog and Shawn Wilder and published in the journal Ecology and Evolution, focused on adult female L. cornutus living in the vegetation along the banks of Lake McMurtry in Noble County, Oklahoma. From mid-June through early October, the team collected twenty spiders during each of seven sampling trips, timed at roughly two- to three-week intervals across the growing season. Each spider was brought into the laboratory and housed individually for seven days under controlled conditions of 25 degrees Celsius and a 14-hour light cycle, with water provided freely. This week-long holding period served a dual purpose: it allowed the animals to clear their guts completely, ensuring that any excreta collected came from the spiders themselves rather than from their last field meal, and it standardized conditions so that differences among sampling dates would reflect seasonal biology rather than laboratory artifacts.

After the holding period, a subset of spiders from each date was frozen, dried at 60 degrees Celsius for 72 hours, weighed to obtain whole-body dry mass, and ground into a homogeneous powder for chemical analysis. Carbon and nitrogen concentrations were measured at the University of Florida Stable Isotope Laboratory, while a broader suite of seventeen additional elements—including phosphorus, potassium, sodium, sulfur, and a range of trace metals—was quantified using inductively coupled plasma optical emission spectrometry at Oklahoma State University. In total, seventy spiders were analyzed for whole-body elemental composition. The remaining spiders were released at sites away from their original collection locations.

Excreta presented a more delicate analytical challenge. Spider waste is produced in tiny quantities, so the researchers pooled low-mass samples from different individuals within each sampling date to obtain enough material for carbon and nitrogen analysis, ultimately processing fifty excreta samples. Because pooling could theoretically distort the data, the team ran a careful series of checks, comparing pooled and unpooled samples for differences in variance, multivariate dispersion, and overall composition. None of these tests detected any effect of pooling, giving the authors confidence that their excreta measurements faithfully reflected the spiders’ waste chemistry. All statistical analyses used generalized linear models with Julian day as a continuous predictor, comparing linear and quadratic seasonal patterns with Akaike’s Information Criterion.

The first major finding concerned body size and waste production. Both followed strikingly similar unimodal trajectories across the season. Spider dry mass rose from early summer, peaked around Julian day 220—August 7—and then declined toward October. Aggregate excreta production followed the same arc, peaking just eight days earlier, around July 30, and falling to its lowest levels at the beginning and end of the sampling period. This tight temporal alignment suggests that mid-summer spiders were both larger and processing more food, likely reflecting peak prey availability during the height of the growing season. The pattern is intuitively satisfying: when resources are abundant, predators eat more, grow more, and excrete more, all at once.

The elemental story, however, proved more surprising. While the carbon and nitrogen concentrations of spider excreta remained essentially stable across the entire season—changes of less than eleven percent that failed to reach statistical significance—the composition of the spiders’ own bodies shifted dramatically. Whole-body nitrogen concentrations declined by 5.77 percent over the season, while phosphorus concentrations moved in the opposite direction, climbing by 25.3 percent. These opposing trajectories in two of the most ecologically important macronutrients mean that a spider eaten by a bird in June delivers a different nutrient package than one eaten in October. Because spiders occupy intermediate trophic levels, serving as both predators and prey, such shifts could ripple through food webs in both directions, altering the timing and composition of nutrient transfer to animals above them and to decomposers below.

The trace element results were even more dramatic. Eight elements—potassium, lithium, manganese, sodium, nickel, sulfur, silicon, and strontium—showed significant seasonal patterns in whole-body concentrations. Lithium rose by nearly 70 percent and silicon by 128 percent over the season, while strontium fell by almost 40 percent. Potassium and sodium followed non-monotonic, mid-season peaks that roughly coincided with the peak in body mass, hinting that shared seasonal drivers such as shifting prey communities or changing physiological demands shape both growth and elemental accumulation. Manganese, sulfur, and strontium have well-established roles in arthropod biology—sulfur in protein structure, strontium as a calcium analog incorporated into the exoskeleton, and manganese in enzymatic reactions and oxidative stress regulation—so their seasonal swings may track genuine physiological needs.

The most eye-catching result of all belonged to nickel, a trace metal with a strong propensity for bioaccumulation. Whole-body nickel concentrations in the spiders increased by a staggering 287 percent across the growing season. Nickel can act as a micronutrient at low doses, but it readily accumulates in arthropod tissues, and previous studies have documented similar accumulation in other spider taxa. The Oklahoma findings suggest that riparian orb-weavers may function as prominent transient sinks for nickel in their food webs, concentrating the metal from their prey and then potentially passing it upward to the birds, wasps, and other spiders that eat them—or releasing it into detrital pathways when they die. Whether consuming nickel-laden spider biomass carries physiological costs for those predators remains an open and potentially important question.

What emerges from this study is a picture of spiders as temporally variable reservoirs of biologically important elements rather than fixed chemical entities. The authors emphasize that the physiological mechanisms behind these shifts remain unresolved. Spiders may prioritize somatic growth early in the season and shift toward reproductive investment later, and because spider eggs differ compositionally from female somatic tissues and can represent a substantial share of total body mass, reproduction could substantially reshape whole-body chemistry. Diet almost certainly plays a role as well: invertebrate prey communities change composition through the season, and elements like lithium and silicon, which appear to be weakly regulated homeostatically, may simply mirror whatever the spiders happen to encounter in their food and environment.

For ecologists, the implications extend well beyond a single species of Oklahoma orb-weaver. If the elemental phenotype of an abundant invertebrate predator can swing this much within a few months, then models of predator-mediated nutrient cycling that assume constant body chemistry may be missing a crucial dimension of temporal variation. Spiders return nutrients to ecosystems through excreta, discarded prey remains, and mortality, and they also export nutrients upward through predation. Quantifying how those fluxes change with the seasons—and how trace metal accumulation in predator biomass affects the animals that consume it—will require integrating ecological stoichiometry with physiology and toxicology. This study provides a template for that integration, and a reminder that even the most familiar backyard predators are chemically far more changeable than they look.

Subject of Research: Seasonal variation in whole-body elemental concentrations and excreta production of the riparian orb-weaving spider Larinioides cornutus

Article Title: Seasonal Variation in Whole‐Body Elemental Concentrations and Excreta Production of a Riparian Orb‐Weaving Spider (Larinioides cornutus)

Article References: Herzog, C., & Wilder, S. M. (2026). Seasonal Variation in Whole‐Body Elemental Concentrations and Excreta Production of a Riparian Orb‐Weaving Spider ( Larinioides cornutus ). Ecology and Evolution, 16(9), Article e74385. https://doi.org/10.1002/ece3.74385

Image Credits: AI Generated

DOI: 10.1002/ece3.74385

Keywords: spiders, ecological stoichiometry, nutrient cycling, trace elements, nickel bioaccumulation, Larinioides cornutus, riparian ecosystems, excreta, seasonal variation, food webs, macronutrients, invertebrate predators

Marine subsidization is a well-documented ecological process in the modern world. Storms and tides routinely deposit marine algae, dead fish, and other ocean-derived organic matter onto beaches, where land-dwelling animals and other organisms exploit it as a convenient food source. Today, this subsidy is especially common in coastal ecosystems and becomes even more important when terrestrial food supplies falter, for example during droughts when inland vegetation is scarce. Seabirds, lizards, mammals, and insects all take advantage of these windfalls. What has remained unknown is how deep into Earth’s history this behavior extends. The new study provides the first identification of marine subsidization in prehistoric ecosystems, pushing the practice back more than 100 million years to the age of dinosaurs.

The key to the discovery lies in a chemical fingerprint carried in tooth enamel. Plants contain both light carbon-12 and heavy carbon-13 isotopes, and the ratio between them, expressed as the delta carbon-13 value, differs depending on where the plants grow. Marine plants generally carry higher carbon-13 values than land plants, and this signature passes up the food chain into the bodies of the animals that eat them. When an animal consumes food, the isotopic ratio is incorporated into its tooth enamel with a predictable upward shift, a difference of roughly 11 to 13 parts per thousand observed in the tooth enamel of living animals. This consistency makes enamel a reliable archive of diet, preserving chemical evidence long after soft tissues have vanished.

For decades, however, dinosaur teeth have presented a puzzle. The difference between the isotopic values of their presumed plant diets and the values recorded in their enamel was consistently higher than the range seen in living animals. Their delta carbon-13 values were also elevated beyond what would be expected for animals eating exclusively land-grown plants, which carry lower values than most marine plants. If dinosaurs, or the prey animals they fed upon, had been consuming marine matter, that extra input of heavy carbon could neatly explain the discrepancy. Testing this hypothesis required comparing fossils from animals that lived near the sea with those from animals that lived far inland, where marine food sources were simply unavailable.

The research team assembled fossils from sites that once lay along the coastlines of the Western Interior Seaway, a vast inland sea that split North America into two landmasses around 100 million years ago, and from the ancient Gulf of Mexico coastline. For comparison, they included fossils from land-locked sites far from any marine influence. The sampled deposits formed during two windows of the Cretaceous Period: the early Albian, roughly 113 to 107 million years ago, and the early Cenomanian, approximately 100 to 96 million years ago. The researchers powdered the fossil specimens for isotopic composition analysis and also applied laser ablation techniques, allowing them to compare chemical signatures across different regions, latitudes, and geological ages.

The results were striking. The delta carbon-13 values recorded in fossils from coastal sites were not only higher than those from the land-locked formation, but they were also consistent between coastal sites regardless of latitude or age. That uniformity is significant, because it points to a shared biological cause rather than random geological variation. According to the authors, coastal-dwelling organisms must have eaten some kind of organic matter originating from the ocean, or prey that had done so themselves. The pattern appeared across the food web, from fish to megaherbivores, indicating that the extra carbon source must have sat low in the food chain to influence both aquatic and terrestrial animals simultaneously.

Identifying the culprit required a process of ecological elimination. The mystery food source had to be an organism living in coastal but not inland habitats, and it had to remain available over many millions of years to explain the consistency of the signal across the Albian and Cenomanian deposits. Few candidates meet these criteria, the researchers concluded, besides marine macroalgae and macrophytes, in other words, seaweeds. Given that large coastal herbivores today almost universally supplement their diets with seaweed when the opportunity arises, the team argues it is likely that most of the sampled herbivorous dinosaurs behaved no differently, browsing on mats of algae and other marine vegetation left behind by the retreating tide.

Not every dinosaur in the dataset joined the beachcombing behavior, and that exception strengthens the case. Tenontosaurus tilletti, a large herbivorous dinosaur found in many locations throughout the Cretaceous, showed no evidence of marine consumption. Its delta carbon-13 value closely resembled that of modern animals that feed exclusively on land-growing plants. This contrast is important because it rules out alternative explanations, such as geological processes that might have altered the chemical traces in tooth enamel after the animals died. If burial conditions had uniformly shifted the isotopic values, all specimens from the same deposits should show the effect. Instead, the elevated signatures track dietary preference, species by species, exactly as a genuine dietary signal would.

The study does have limits that the authors acknowledge. The dataset clearly demonstrates marine subsidization in the coastal deposits examined, but it lacks data from polar and equatorial latitudes during the early Albian and early Cenomanian. Future research, the team notes, needs to determine whether the phenomenon was common across different latitudes and other time periods, such as the preceding Jurassic Period or the subsequent early Cenozoic Era. Even so, the implications reach beyond paleontology. As Forster concluded, the study emphasizes the connections between terrestrial and marine ecosystems, which are deeply intertwined and have been for hundreds of millions of years. Understanding those ancient linkages, the authors argue, highlights the importance of protecting the environmental connections that still exist along coastlines today.

Subject of Research: Marine subsidization of dinosaur-era coastal ecosystems revealed through carbon isotope analysis of fossil tooth enamel

Article Title: Dinos snacked on seafood washed up on ancient beaches, fossil study shows

Article References: Dinos snacked on seafood washed up on ancient beaches, fossil study shows. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: dinosaurs, marine subsidization, carbon isotopes, tooth enamel, Cretaceous, Western Interior Seaway, seaweed, paleoecology, coastal ecosystems, Frontiers in Ecology and Evolution, Tenontosaurus, food webs

The first study, published in Ecology, turns its attention to one of the world’s most extraordinary amphibians, the Japanese giant salamander. Adults of this species can reach a staggering 1.5 meters, roughly five feet, in length, and a new analysis of their feeding ecology reveals that size transforms them into entirely different ecological actors. By analyzing naturally occurring chemical markers in animal tissues, markers that function as biological records of who eats whom in a food web, researchers demonstrated that juvenile salamanders compete directly with fish, prawns and turtles for the same prey in the fast-flowing mountain rivers and streams they inhabit. As the animals grow, however, they climb the food chain, expanding into a more distinct ecological niche and leaving their former competitors behind.

By the time Japanese giant salamanders reach maturity, they have become apex predators, and in a striking ecological twist, they prey on many of the very species with which they once competed. This ontogenetic shift, the technical term for the change in ecological role across an animal’s life stages, has cascading consequences for how nutrients move through river food webs, increasing the overall complexity of the ecosystem. The conservation implications are profound. Because juveniles, intermediate-sized adults and fully grown top predators each perform different functional roles, the loss of salamanders at any one life stage could produce dramatically different effects on freshwater ecosystems across Japan. Protecting a species, the study suggests, means protecting every phase of its life history.

A second study, appearing in Ecological Applications, addresses a deceptively simple question with enormous practical stakes: which species should scientists monitor to detect ecological change? As biodiversity shifts in response to climate change, forest management and other pressures, it is impossible to continuously track every organism in an ecosystem. Routine monitoring of carefully selected indicator species offers a workaround, but choosing the wrong species can be a costly mistake. Researchers in Finland tackled this challenge by analyzing data from 3,000 sites across the country, searching for understory plants that would serve as the most effective early-warning signals for forest ecosystems.

The Finnish team focused on the relationships among plants and between plants and their physical environment. They found that while some species were strongly associated with other plants and others were tightly linked to environmental factors such as soil type or climate, a small handful showed robust connections to both. This dual sensitivity marked those plants as especially promising indicators, because they can signal changes in both the living and nonliving components of an ecosystem simultaneously. The researchers caution, however, that forestry practices, forest condition and other factors can themselves reshape interactions between plants and their environment, so these influences must be built into the selection process. Because monitoring programs are typically expensive, time-consuming and labor-intensive, a framework that identifies species reflecting changes in both biological and physical realms could substantially improve the efficiency and effectiveness of ecosystem monitoring worldwide.

The third study, published in Ecosphere, ventures into one of ecology’s most counterintuitive territories: what happens to biological rhythms when an organism lives where there is no daylight, little temperature variation and few other environmental cues? Many animals rely on internal biological clocks to maintain daily and seasonal routines, but researchers wondered whether cave-dwelling and groundwater species lose these clocks entirely. The team studied three such animals: a cave-dwelling salamander, a subterranean amphipod and a shrimp-like crustacean living in groundwater. Because these creatures often inhabit fragile, hard-to-reach environments where intensive monitoring would be impractical or disruptive, the researchers deliberately avoided laboratory experiments.

Instead, they repeatedly surveyed the animals in their natural habitats, recording when individuals were observed, how often they appeared and how many were present. The logic was elegantly simple: if animals consistently showed up more often at certain times, that pattern could indicate recurring activity driven by an internal clock. The surveys revealed evidence of regular daily or seasonal activity patterns in two of the three species, while the third showed no clear rhythmic behavior. The findings challenge the long-standing assumption that biological clocks are universally lost among inhabitants of highly stable environments, demonstrating instead that many species retain them despite living under seemingly unchanging conditions. For scientists studying these unusual and difficult-to-access animals, the framework offers a noninvasive and highly adaptable tool for detecting biological rhythms in organisms living under relatively constant conditions.

The fourth study, in Ecological Monographs, delivers a sobering assessment of nutrient pollution in seagrass ecosystems. Seagrass beds are major carbon stores, biodiversity hotspots and critical nurseries for commercially valuable fish and shellfish, making them among the most valuable coastal habitats on Earth. Yet researchers in China found that excessive nitrogen, phosphorus and other nutrients washing into coastal waters can render seagrass food webs markedly less efficient. In beds exposed to high nutrient levels, the efficiency with which energy moved through the food chain fell by 32 percent, a decline with implications for everything from fish stocks to ecosystem stability.

Essential fatty acids, nutrients required for growth, reproduction and healthy cell function, were especially affected. The researchers propose that excess nutrients alter both the nutritional quality and the chemical defenses of seagrasses, making them less appealing to snails and other grazers. As a result, long-chain polyunsaturated fatty acids, or PUFAs, which contribute directly to the nutritional value of seafood, declined by as much as 62 percent in their transfer through the food web. Scaled globally, the team estimates that nutrient-enriched seagrass beds could lose roughly 2 million metric tons of carbon energy and 63,500 metric tons of PUFAs through food-chain transfer each year. Such reductions could ultimately erode ecosystem stability, diminish fisheries productivity and degrade the nutritional quality of seafood that billions of people depend upon.

The final study, published in Frontiers in Ecology and the Environment, uncovers an unexpected conservation ally in China’s countryside. Fengshui forests, small patches of woodland maintained for cultural and spiritual purposes, are modest in size, scattered across the landscape and exposed to greater human impact than formal nature reserves. Yet an analysis of 811 of these culturally significant woodlands in southern China revealed that they harbor a remarkable diversity of plants and animals. The forests provide especially critical sanctuary for threatened evergreen broadleaf forest ecosystems and support upward of 60 rare or endangered tree species.

The researchers propose that incorporating village fengshui forests into national management strategies could greatly expand the reach of biodiversity protection in China and at least partially offset the geographic limitations of formal protected areas. More broadly, the study adds to growing evidence that ecosystems protected for cultural, religious or other socially relevant purposes often serve as safe havens for biodiversity, even in regions where rapid human encroachment threatens to engulf everything in its path. Together, the five studies underscore a unifying lesson for twenty-first-century ecology: whether the question concerns a giant salamander’s changing appetite, the choice of a monitoring sentinel, the hidden clocks of cave dwellers, the chemistry of polluted seagrass meadows or the sacred groves of rural villages, careful measurement of ecological relationships remains the foundation of effective conservation, and the answers are often found where nature and human culture intersect.

Subject of Research: Ecological research on food webs, indicator species, biological rhythms, seagrass eutrophication and culturally protected forests

Article Title: Research news from the Ecological Society of America’s journals

Article References: Research news from the Ecological Society of America’s journals. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: giant salamander, food webs, indicator species, biological rhythms, cave ecosystems, seagrass, eutrophication, fatty acids, fengshui forests, biodiversity conservation, freshwater ecosystems, ecological monitoring

The research, published in BMC Biology by Andrew Y. Morozov of the University of Leicester, Boris W. Berkhout of the University of Amsterdam, and Donald DeAngelis of the University of Miami, combines laboratory experiments on a striking freshwater predator with a new mathematical framework that explicitly represents the internal structure of predator populations. The team’s central claim is provocative: if individual foragers develop stable preferences for particular food resources, then feeding cannot be described using traditional functional responses based on total predator density alone.

The empirical anchor of the study is the assassin snail, Anentome helena, a freshwater gastropod that feeds on other, non-predatory snails. On paper, this species looks like a textbook generalist: across its range it attacks a variety of prey snails, and the population as a whole exploits a broad feeding niche. But when the researchers ran controlled feeding experiments, offering individual assassin snails a menu of prey species including ramshorn snails, trumpet snails, pond snails, and quilted melania snails, a very different picture emerged. Individual predators displayed strong and persistent preferences for particular prey types, and the feeding niche of each individual was far narrower than that of the predator population as a whole.

This pattern, in which a generalist population is effectively composed of cohorts of specialists, is not merely a curiosity of snail behaviour. The authors argue it is likely widespread in nature, arising whenever individual predators learn to handle one prey type efficiently, imprint on a particular foraging strategy, or simply differ in their innate tendencies. In such populations, the aggregate functional response measured at the population level is a statistical artefact, a blend of many narrow individual responses, and using it in models can mask the true dynamics of predation.

To address this, the researchers developed a generic modelling framework in which the predator population is explicitly divided into specialist cohorts, each dedicated to a particular prey species. Crucially, individuals are not locked into their cohorts forever. The framework allows predators to switch between specialist strategies, with the switching governed by the relative profitability of each foraging option. When a particular prey species becomes abundant and profitable, more predators drift toward specialising on it; when that prey declines, individuals gradually abandon the strategy and adopt alternatives. This dynamic reallocation of foraging effort within the predator population is the mathematical heart of the new approach.

The team embedded this structured predator population into a tri-trophic food web model, complete with a basal resource, multiple competing prey species, and the cohort-structured predator. They then compared its behaviour against two classical alternatives: a model in which the generalist predator feeds on all prey according to a multi-prey Holling type III functional response with frequency-dependent food selectivity, and a model in which the prey are each attacked by their own dedicated specialist predator species. The comparison reveals just how much hinges on the assumption of homogeneity within predator populations.

The most striking result concerns coexistence. In the classical framework, a generalist predator feeding on several competing prey tends to destabilise the system or eliminate inferior competitors, because the predator concentrates its attack on whichever prey is currently most abundant, driving boom-and-bust cycles that often end in extinctions. In the new cohort-structured model, by contrast, the internal division of labour within the predator population promotes the coexistence of competing prey species. Because only a fraction of the predator population specialises on any given prey at a time, no single prey species faces the full brunt of predation, and inferior competitors can persist in the shadow of their dominant rivals.

Yet coexistence comes with a caveat that ecologists may find unsettling: the outcome depends on the initial configuration of specialist cohorts within the predator population. In other words, the same community, with the same species and the same environmental conditions, can arrive at different long-term states depending on how the predators’ dietary specialisations were distributed at the start. This sensitivity to initial conditions challenges the classical assumption that ecological communities converge on a predictable equilibrium determined solely by their parameters.

The model also generates a dynamical pattern that, according to the authors, has not been reported in previous predator-prey models: pronounced oscillations in prey densities while the total predator density remains approximately constant. In this regime, the predator population acts as a kind of steady regulatory backdrop, its overall numbers barely changing, while the composition of its specialist cohorts shifts continuously in response to the fluctuating prey. Individual prey species rise and crash in succession, but the predator community as a whole absorbs these swings through internal reallocation rather than demographic change. This decoupling of prey fluctuations from predator abundance is invisible to any model that treats the predator as a homogeneous mass.

Beyond these specific findings, the framework points to broader ecological implications. The authors highlight the potential for long-term ecological transients, extended periods in which community composition keeps shifting for very long times before settling, if it settles at all. Such transients could help explain why some ecosystems appear to be in perpetual flux even under stable environmental conditions. The structured-predator perspective also offers a mechanistic route to the high biodiversity observed in many natural communities, suggesting that the hidden dietary structure within predator populations may be an underappreciated engine of species coexistence.

The study amounts to a critical reappraisal of one of ecology’s oldest modelling conventions. The functional response has served the field well, but the authors argue it rests on an implicit assumption of homogeneity that frequently fails in nature. Their alternative does not discard the functional response entirely; rather, it embeds individual feeding preferences and strategy switching into the population-level description, producing a richer and, they argue, more realistic account of how generalist predators regulate prey. For ecologists modelling pest control, conservation, or food web dynamics, the message is that who eats what within a predator population matters just as much as how much the population eats in total.

The work also illustrates the value of pairing simple experimental systems with abstract theory. The assassin snail, a popular species in the aquarium trade, provided a tractable window into individual-level feeding decisions that would be difficult to observe in large vertebrate predators. By translating those observations into a general mathematical structure, the researchers have produced a tool that can, in principle, be applied wherever individual predators show stable dietary specialisation, from insects parasitising specific host species to fish specialising on particular foraging grounds.

As food web ecology grapples with predicting how communities will respond to environmental change, models that capture within-population structure may prove essential. If generalist predators everywhere are really assemblies of hidden specialists, then the regulation of prey populations, and the biodiversity those populations support, may depend on dynamics that classical theory has never been able to see.

Subject of Research: Modelling the regulation of prey populations by generalist predators composed of individual feeding specialists

Article Title: A novel framework to modelling regulation of prey populations by a generalist predator

Article References: Morozov, A. Y., Berkhout, B. W., & DeAngelis, D. (2026). A novel framework to modelling regulation of prey populations by a generalist predator. BMC Biology. https://doi.org/10.1186/s12915-026-02732-2

Image Credits: AI Generated

DOI: 10.1186/s12915-026-02732-2

Keywords: predator-prey interaction, functional response, generalist predator, food webs, Anentome helena, ecological modelling, species coexistence, ecological transients, feeding behaviour, specialist cohorts, population structure, theoretical ecology