Herbivore responses to host plant concentration and plant community diversity are predicted to depend on diet breadth, yet most studies to date have focused on dietary specialists. The few that have included generalist herbivores have largely been conducted in agricultural settings or measured resources at a single spatial scale, leaving it unclear whether these predictions hold in natural systems across multiple spatial scales. Here, we examine how host plant concentration and plant community diversity shape the population densities of dietary specialist and generalist larval Lepidoptera (caterpillars) in secondary forests of New England. We measured host plant assemblages and densities at scales from 3-400 m to assess the patch size-specific effects of host concentration and plant diversity. To accurately characterize the resource landscape for herbivores that consume > 1 host species, we weighted host plant concentration by electivity (a measure of each species' observed frequency of association with each host plant relative to its availability) and demonstrate that this weighting is necessary to detect responses that are otherwise obscured. We found that dietary generalists' population densities correlated positively with their host plant concentrations at scales up to 25 m, a pattern that was only detectable when electivity was considered. In contrast, dietary specialists' population densities correlated positively with their host plant densities at scales < 3 m and negatively at scales 25-50 m. This suggests that specialists aggregate in small, dense patches of resources, while their density saturates or declines at intermediate scales, consistent with resource dilution, not concentration. Neither generalist nor specialist caterpillar populations responded strongly to plant community diversity at any scale. These findings demonstrate that herbivore responses to resource concentration are contingent on diet breadth and spatial scale, that detecting generalist responses requires diet- breadth-appropriate measurement, and that the influence of plant diversity on herbivore density documented in agroecosystems may not generalize to structurally complex natural forests.

Global projections indicate that between 20% and 90% of current coastal wetland areas may be lost due to sea-level rise (SLR), depending on the severity of the scenario. Warming, acidification and other global change stressors such as eutrophication also show negative impacts on coastal wetlands. Such a scenario poses a dramatic threat to biodiversity, particularly in deltas and estuaries, which are vital for the conservation of coastal species and ecosystem functions. This paper summarizes the main impacts of climate change on coastal wetland biodiversity, with focus on vegetation, birds and fish. Management options to cope with climate change impacts are also summarized. Many coastal wetlands are already undergoing degradation or disappearing due to the combined impacts of climate change and other global drivers, including SLR, subsidence, sediment deficits, coastal erosion, and salt stress. Coastal squeeze, the restriction of natural habitat migration due to human infrastructure and natural constraints, also threatens these ecosystems. Enhancing the resilience of coastal wetlands involves improving hydrological connectivity, increasing sediment inputs, boosting wetland plant productivity, and allowing space for natural coastal processes. However, these efforts are highly dependent on active conservation, management and restoration policies. The future of coastal wetland biodiversity will vary significantly based on the climate scenarios that unfold, and the policies implemented. Highlights Coastal wetland biodiversity has severely declined due to habitat loss and other aspects of global change. Remaining wetlands are endangered by climate change impacts such as sea level rise.Salt marshes are the most endangered coastal wetlands in Europe, along with their associated flora and fauna. The Mediterranean coast may lose up to 90% of those habitats by the end of the 21st century due to sea level rise.Boosting coastal wetland resilience is critical to avoid biodiversity loss. To do this requires increasing the pace and scale of coastal wetland restoration, and enhancing the ecogeomorphic dynamics through the increase of hydrological connectivity and the supply of sediments to the coasts.

Land-cover conversion is currently the greatest threat to avian biodiversity, but climate change will increasingly dictate the future of bird populations. In many respects, the effects of climate change on birds will be similar to other threats that conservation practitioners already work to address. The magnitude of change, however, may be quite different. Effects will increasingly play out across large portions of a species geographic range, relatively quickly, and somewhat simultaneously; will likely interact with other threats in unknown ways; and will influence many components of ecosystems with which birds interact, often with poorly understood consequences. Human responses to climate shifts also could transform the planet in multiple ways, with far-reaching effects on biological diversity. Long-term conservation of bird populations will require substantial advance planning if losses are to be minimized.

Coarse habitat models are often used in decision-making, yet fine-scale data frequently capture local conditions relevant for vulnerable species conservation. Across the northeastern USA, managers are restoring salt marshes to promote resiliency in the face of accelerated sea-level rise. The saltmarsh sparrow (Ammospiza caudacuta), an avian tidal marsh specialist, faces potential extinction due to declining habitat. It has become a flagship species for salt marsh conservation and is also an indicator of changes to the broader ecosystem. This study evaluates a marsh-scale management model developed to identify priority habitat for saltmarsh sparrows in New Hampshire. This model characterizes marshes as single units, potentially missing key fine-scale (local) features that affect species occurrence. To identify the best predictors of saltmarsh sparrow occurrence, covariates from the marsh-scale model were compared with local features capturing fine-scale variability, with occupancy modeled using data from surveys conducted across 86 points on New Hampshire salt marshes. Several metrics of marsh quality used in the marsh-scale model had no relationship to saltmarsh sparrow occurrence, whereas key local covariates were better predictors. Predicted saltmarsh sparrow occupancy increased from 1

Conservation actions often assume implicitly that heritabilities are zero and that threatened populations cannot adapt to changing environments. To illustrate, we evaluated the last 10 y of recovery plans for US threatened and endangered species and found that only 4% assessed within-population adaptability. This omission reflects the common assumption that population adaptation is too slow or inconsequential to affect conservation practice in the short term. Yet, the median heritability (h2) and evolvability (IA) across many studies are not zero as assumed, but 0.3 and 0.4, respectively, based on a compilation of estimated values. This moderate heritability could rescue some populations. By compiling literature on conservation assessments, we detail how considering adaptability can shift conservation priorities, alter management recommendations, and provide additional ways to rescue declining populations and species. Based on these findings, we advocate for including population adaptability into conservation plans and adopting the prior expectation of moderate adaptability (h2 = 0.3, IA = 0.4) along with its uncertainty, as a starting point when better information is lacking. This moderate adaptability could allow some species to respond naturally to environmental change while directing limited resources toward the species that need it most.

The determinants of population variability across taxa, time, and space are not fully understood, particularly for insects, a group with recent reports of widespread abundance declines. We collated data from unpublished and published sources to calculate indices of interannual population variability for over 4500 unique insect time series, comprising data from nearly 1500 species. We evaluate whether insects exhibit greater population variability than other types of animals. Our results demonstrate that insects as a group indeed exhibit much greater population variability than birds, mammals, or fish, but that within Insecta, included orders show similar levels of population variability. We also find that population variability in insects is greater at higher latitudes, for species with smaller body sizes and for shorter, older time series and that it varies between biomes. Overall, our findings can inform the interpretation and prediction of insect population trends, fluctuations and extinction risk in an era of insect decline.

Biodiversity is declining in many parts of the world. Biological diversity measurement and monitoring are fundamental to the assessment of the causes and consequences of environmental changes, identification of key areas for the protection of biodiversity or ecosystem services, determining the effectiveness of actions, and the creation of decision-support tools critical to maintaining a sustainable planet. Biodiversity measurement is rapidly changing due to advances in citizen science, image recognition, acoustic monitoring, environmental DNA, genomics, remote sensing, and AI. In this perspective, we outline the exciting opportunities these developments offer but also consider the challenges. Our key recommendations are to 1) Capitalize on the ability of novel technology to integrate data sources 2) agree to standard methods for data collection 3) ensure new technologies are calibrated with existing data; 4) fill data gaps by using emerging technologies and increasing capacity, especially in the tropics; 5) create living safeguarded databases of trusted information to reduce the risk of poisoning by AI hallucinated, or false, information; 6) ensure data generation is valued; 7) ensure respectful incorporation of Indigenous Knowledge; 8) ensure measurements enable the quantification of effectiveness of actions, and 9) increase the resilience of global datasets to technical and societal change. Radical new collaborations are needed between computer scientists, engineers, molecular biologists, data scientists, field ecologists, citizen scientists, Indigenous peoples, policymakers, and local communities to create the rigorous, resilient, accessible biodiversity information systems required to underpin policies and practices that ensure the maintenance and restoration of ecological systems.

Abstract To improve ecosystem restoration, synthesizing information from multiple projects to identify approaches that achieve desired goals is needed. Distributed management experiments can be challenging when individual project objectives vary, and local site conditions can mediate responses; yet coordinated, systematic approaches promise improved understanding and longer term efficiency. Precipitous declines in the global extent of saltmarsh have stimulated rapid increases in restoration activities, but outcomes remain challenging to predict. We tested the responses of bird and vegetation communities to two types of restoration—sediment addition and hydrological modification—across 30 restored marshes along the USA's Atlantic Coast, up to 7 years post‐restoration. To determine if site conditions mediated responses, we also examined the effects of site‐level attributes, such as tidal amplitude and latitude. We found that projects that raised elevation via sediment addition increased the cover of vegetative species of interest, while those that modified hydrology without altering elevation had mixed effects on vegetation. The effects of sediment addition and hydrological modification were more limited for avian species, but results suggest that increases in both abundance and diversity can materialize through modification of the vegetative community. The magnitude of the restoration effect was mediated by site‐level attributes, including tidal amplitude, marsh elevation and latitude. Policy Implications : Our findings demonstrate that saltmarsh restoration can yield measurable ecological benefits within a few years, but outcomes depend strongly on local site conditions. Restoration strategies that increase elevation are more likely to produce consistent vegetation benefits, while outcomes of hydrological modification are more context dependent and variable. Our results highlight the importance of incorporating site‐specific factors into restoration planning and tailoring approaches accordingly. Long‐term monitoring over decadal timescales is essential to evaluate true project outcomes and to guide future adaptive management.

Achieving the goals of the Kunming-Montreal Global Biodiversity Framework (GBF) requires monitoring systems that can transform heterogeneous observations into consistent, decision-relevant knowledge. Yet current biodiversity data are fragmented, uneven in quality, and seldom comparable across space or time. Existing standards such as Darwin Core, Findable, Accessible, Interoperable, and Reusable (FAIR) and Collective Benefit, Authority to Control, Responsibility, and Ethics (CARE) principles provide important foundations, but they do not connect the full chain from field observation to policy reporting. We introduce the Biodiversity Monitoring Standards Framework (BMSF)-a unifying architecture that links ethical principles, standardized data collection, accredited analytical workflows, and transparent reporting into a single auditable "chain of evidence." The framework's novelty lies in its tiered and federated design, enabling national agencies, Indigenous knowledge holders, local communities, and private-sector actors to operate under shared principles while maintaining data sovereignty. By integrating Essential Variables, accredited analytical methods, and open-source implementation pathways, the BMSF allows locally generated data to be aggregated into credible, comparable indicators aligned with GBF targets. Concrete application, such as a national forest-connectivity assessment, demonstrates how the BMSF improves reproducibility, transparency, and policy relevance relative to existing approaches. Implemented generally, this framework would convert fragmented monitoring efforts into a coordinated, scalable system capable of tracking and guiding collective progress toward halting and reversing biodiversity loss.

Archaea are generally low-abundance members of the vertebrate microbiota that require specific PCR primers to be detected in metabarcoding studies, and the robust intraspecific sample size is necessary for well-supported conclusions about archaeal diversity. Using 16S rRNA gene amplicons generated using both Archaea-Specific and Universal primers, we investigated prokaryotic diversity in 110 fecal samples from four wild bird species from four different orders: Anna's Hummingbird (Calypte anna), Saltmarsh Sparrow (Ammospiza caudacuta), Ruddy Turnstone (Arenaria interpres), and Canada Goose (Branta canadensis). Our aim was to test the hypotheses that Archaea-Specific primers would offer higher resolution of archaeal diversity and that the four ecologically distinct host species would have distinct archaeal communities. Archaea-Specific primers resulted in increases in archaeal richness and detection of Archaea in all four birds compared to the Universal primers. The ammonia-oxidizing archaeal order Nitrososphaerales was detected in all four host species, and methanogenic orders were enriched in samples from Canada Geese. In Bacteria-Archaea co-occurrence networks, Archaea-Specific primers found many more significant interactions than the Universal primers alone. Methanogenic archaeal orders dominated the microbiota in Canada Geese and were found to a lesser extent in the other host species, suggesting an important functional role of methanogens in Canada Geese. Overall, this study advances our knowledge of the archaeal component of the microbiome in wild birds and provides insight into the potential functional roles Archaea play in studies of avian gastrointestinal microbiota. IMPORTANCE:Archaea may be persistent members of host-associated microbiomes across diverse host taxa; their detection has been limited due to their low abundance and the inadequacy of Universal primers. Large-scale studies of Archaea in vertebrate microbiomes have historically had low intraspecific sample sizes for bird species and had conflicting results. This study demonstrates the improved capability of the Archaea-Specific primers to detect archaeal diversity in diverse avian host species compared to the widely used Universal primers. We also identified both shared and species-specific archaeal taxa across four ecologically distinct avian host species from four different orders with implications for functional importance. Future studies interested in comprehensively cataloging prokaryotic diversity in avian microbiomes using amplicon-based sequencing methods should include Archaea-Specific primers to adequately probe archaeal diversity.

Scientific and public interest in the global status of insects has surged recently; however, understanding the relative importance of different stressors and their interconnections remains a crucial problem. We use a meta-synthetic approach to integrate recent hypotheses about insect stressors and responses into a network containing 3385 edges and 108 nodes. The network is highly interconnected, with agricultural intensification most often identified as a root cause. Habitat-related variables are highly connected and appear to be underdiscussed relative to other stressors. We also identify biases and gaps in the recent literature, especially those generated from a focus on economically important and other popular insects, especially pollinators, at the expense of non-pollinating and less charismatic insects. In addition to serving as a case study for how meta-synthesis can map a conceptual landscape, our results identify many important gaps where future meta-analyses will offer critical insights into understanding and mitigating insect biodiversity loss.

To halt and reverse the trends of ecosystem loss and degradation under global change, nations globally are promoting ecosystem restoration. Restoration is particularly crucial to coastal wetlands (including tidal marshes, mangrove forests, and tidal flats), which are among the most important ecosystems on Earth but have been severely depleted and degraded. In this review, we explore the question of how to make restoration more effective for coastal wetlands in light of the often-overlooked dynamic nature of these transitional ecosystems between land and ocean. Currently, restoration efforts have focused on removing anthropogenic threats, habitat reconstruction, and planting foundation species, often with mixed success and high costs. The challenges largely lie in the abiotic and biotic dynamics of these transitional ecosystems, including (i) fluctuating environmental stresses, (ii) variable trophic and nontrophic species interactions, (iii) changing connectivity with adjacent land, sea, and freshwater systems, and (iv) accelerating climate change, including sea level rise, droughts, and storms. Future restoration should explicitly account for these abiotic and biotic dynamics from threat removal to habitat reconstruction, assisted succession, and post-restoration management. We highlight novel yet practical measures to enhance success. In the coming decades, bending the curve of coastal wetland loss and degradation globally also requires better understanding of the abiotic and biotic dynamics of these transitional ecosystems prone to change, using this understanding to develop innovative restoration approaches, and applying new approaches to upscale restoration in synergy with socioeconomic development. Critical to these efforts are collaborations among ecologists, policymakers, business investors, restoration practitioners, and the many millions of people dependent on coastal wetlands.

Historically, the fates of individual passerines during migration have been informed primarily by scarce data on band recaptures and resighting. This constraint is particularly problematic for imperiled passerines because information on the timing and pathways of migration is not available to inform the development of effective actions necessary to reverse declines. We used automated telemetry stations to investigate the migratory ecology and movements of the globally endangered Saltmarsh Sparrow (Ammospiza caudacuta), for which the specifics of migratory behavior are poorly known. This short-distance migrant relies solely on coastal salt marshes in the eastern USA, breeding from Maine to Virginia, and migrating as far south as Florida. Saltmarsh Sparrows from different breeding (Maine, Massachusetts, and Rhode Island) and non-breeding (South Carolina and Georgia) latitudes generally followed similar migration routes, but individuals often had differences in departure dates. Movements were predominantly coastal, but detections suggest that sparrows also make inland and over-ocean migratory flights, particularly between southern New England and the mid Atlantic. In fall, we detected multiple stopovers in coastal Connecticut, Rhode Island, and New Jersey, and identified spring stopover sites along the Delmarva Peninsula. Most fall stopovers lasted < 2 days, and stopover length decreased throughout the migratory season. Sustained migratory flights occurred only at night. More than 93% of migratory flights were associated with tailwinds at departure, and estimated flight ground speeds correlated weakly with tailwind support. Our research provides new understanding of migratory timing, pathways, and stopover use, which will inform actions such as land protection, marsh restoration, and the siting of near-shore wind development.

Salt marshes in the northeastern United States support several specialized breeding bird species that are threatened by sea level rise (SLR) and coastal development, processes that drive habitat change and fragmentation. There have been rapid, widespread declines in some species, but mechanisms driving population change and whether declines continue remain unclear. We examined the influence of phenomena expected to modify salt marshes, including SLR, sediment delivery rates, and land use, on the population trajectories of saltmarsh breeding birds. We modeled population trajectories of 5 species with spatially extensive point count surveys conducted from Maine to Virginia from 2011 to 2022. We used Bayesian hierarchical abundance models and model selection to identify phenomena that had the strongest effect on population change. Clapper rails (Rallus crepitans) continued their long-term decline (-4.1%/year). Willets (Tringa semipalmata semipalmata) (2.6%/year) and saltmarsh sparrows (Ammospiza caudacuta) (4.1%/year) increased, and seaside (Ammospiza maritima) and Nelson's (Ammospiza nelsoni subvirgatus) sparrows exhibited no clear change in abundance. The estimated increase for saltmarsh sparrow was not consistent with trends over the previous 25 years but aligned with prior demographic modeling, which predicted a short-term stabilization during the study years before an expected return to a long-term decline. Road density and other tidal restrictions near marshes were generally good predictors of abundance over the study period, as was marsh habitat composition. Local rates of SLR and sediment delivery were not as good predictors. During periods of relatively low rates of realized SLR, local-scale drivers of population trends had relatively stronger effects than global drivers on the persistence of several saltmarsh breeding birds. Conservation practitioners, however, should be attentive to global drivers, especially as rates of SLR accelerate in the future.

Growing evidence suggests that organisms with narrow niche requirements are particularly disadvantaged in small habitat patches, typical of fragmented landscapes. However, the mechanisms behind this relationship remain unclear. Dietary specialists may be particularly constrained by the availability of their food resources as habitat area shrinks. For herbivorous insects, host plants may be filtered out of small habitat fragments by neutral sampling processes and deterministic plant community shifts due to altered microclimates, edge effects and browsing by ungulates. We examined the relationship between forest fragment area and the abundance of dietary‐specialist and dietary‐generalist larval Lepidoptera (caterpillars) and their host plants in the northeastern USA. We surveyed caterpillars and their host plants over 3 years in equal‐sized plots within 32 forest fragments varying in area between 3 and 1014 ha. We tested whether the abundances and species richness of dietary specialists increased more than those of dietary generalists with increasing fragment area and, if so, whether the difference could be explained by reduced host plant availability or increased browsing by white‐tailed deer ( Odocoileus virginianus ). The overall abundance of dietary specialists was positively related to fragment area; the relationship was substantially weaker for dietary generalists. There was notable variation among species within diet breadth groups, however. There was no effect of fragment area on the diversity of dietary‐specialist or dietary‐generalist caterpillars. Deer activity was not related to the abundances of either dietary‐generalist or dietary‐specialist caterpillars. Plant community composition was strongly associated with fragment area. Larger fragments were more likely to include host plants for both dietary‐specialist and dietary‐generalist caterpillars. Deer activity was correlated with decreased host plant availability for both groups, with a slightly stronger impact on host plants of dietary specialists. Although dietary specialists were more likely to lack host plants in fragments, the relationship between fragment area and host availability did not depend on caterpillar diet breadth. This study provides further evidence that decreasing patch area disproportionately impacts specialist consumers. Because this relationship was derived from equal‐sized plots, it is robust to some criticisms levelled at fragmentation research. The mechanisms for specialist consumer declines, however, remain elusive.

How species richness scales spatially is a foundational concept of community ecology, but how biotic interactions scale spatially is poorly known. Previous studies have proposed interactions-area relationships (IARs) based on two competing relationships for how the number of interactions scale with the number of species, the ‘link-species scaling law’ and the ‘constant connectance hypothesis.’ The link-species scaling law posits that the number of interactions per species remains constant as the size of the network increases. The constant connectance hypothesis says that the proportion of realized interactions remains constant with network size. While few tests of these IARs exist, evidence for the original interactions-species relationships are mixed. We propose a novel IAR and test it against the two existing IARs. We first present a general theory for how interactions scale spatially and the mathematical relationship between the IAR and the species richness-area curve. We then provide a new mathematical formulation of the IAR, accounting for connectance varying with area. Employing data from three mutualistic networks (i.e. a network which specifies interconnected and mutually-beneficial interactions between two groups of species), we evaluate three competing models of how interactions scale spatially: two previously published IAR models and our proposed IAR. We find the new IAR described by our theory-based equation fits the empirical datasets equally as well as the previously proposed IAR based on the link-species scaling law in one out of three cases and better than the previously-proposed models in two out of three cases. Our novel IAR improves upon previous models and quantifies mutualist interactions across space, which is paramount to understanding biodiversity and preventing its loss.

Salt marshes in the northeastern United States provide critical breeding habitat for tidal marsh specialist birds like the Ammospiza caudacuta (Saltmarsh Sparrow). The Ammospiza caudacuta population declined by 9% annually from 1998 to 2012, necessitating immediate conservation actions for this vulnerable species. However, estimating species vital rates across a large geographic region is logistically challenging and cost prohibitive. Therefore, we developed and tested a rapid assessment monitoring protocol focused on reproductive metrics to enhance future conservation planning. We used 3 years (2018, 2019, and 2021) of intensive demographic data from 12 sites to estimate daily nest survival, nest period success, fledglings produced per female, and successful broods per female. We implemented the rapid assessment protocol co-located at intensive sites in the same years to estimate the number of captured females and juveniles. We used Pearson’s correlation analyses to determine the association of intensive metrics with rapid metrics. We found that the sum of Ammospiza caudacuta female and juvenile captures was positively correlated with daily nest survival (r = 0.61, P = 0.01), nest period success (r = 0.70, P = 0.002), fledglings produced per female (r = 0.82, P < 0.001), and successful broods per female (r = 0.82, P < 0.001). Our results demonstrate that fixed-effort mist-netting from our rapid assessment protocol is an informative and time-efficient sampling method that can aid in making informed management decisions related to Ammospiza caudacuta conservation.

Determining factors that shape a species' population genetic structure is beneficial for identifying effective conservation practices. We assessed population structure and genetic diversity for Saltmarsh Sparrow (Ammospiza caudacuta), an imperiled tidal marsh specialist, using 13 microsatellite markers and 964 individuals sampled from 24 marshes across the breeding range. We show that Saltmarsh Sparrow populations are structured regionally by isolation-by-distance, with gene flow occurring among marshes within similar to 110 to 135 km of one another. Isolation-by-resistance and isolation-by-environment also shape genetic variation; several habitat and landscape features are associated with genetic diversity and genetic divergence among populations. Human development in the surrounding landscape isolates breeding marshes, reducing genetic diversity, and increasing population genetic divergence, while surrounding marshland and patch habitat quality (proportion high marsh and sea-level-rise trend) have the opposite effect. The distance of the breeding marsh to the Atlantic Ocean also influences genetic variation, with marshes farther inland being more divergent than coastal marshes. In northern marshes, hybridization with Nelson's Sparrow (A. nelsoni) strongly influences Saltmarsh Sparrow genetic variation, by increasing genetic diversity in the population; this has a concomitant effect of increasing genetic differentiation of marshes with high levels of introgression. From a conservation perspective, we found that the majority of population clusters have low effective population sizes, suggesting a lack of resiliency. To conserve the representative breadth of genetic and ecological diversity and to ensure redundancy of populations, it will be important to protect a diversity of marsh types across the latitudinal gradient of the species range, including multiple inland, coastal, and urban populations, which we have shown to exhibit signals of genetic differentiation. It will also require maintaining connectivity at a regional level, by promoting high marsh habitat at the scale of gene flow (similar to 130 km), while also ensuring "stepping stone" populations across the range.

Reports of declines in abundance and biomass of insects and other invertebrates from around the world have raised concerns about food limitation that could have profound impacts for insectivorous species. Food availability can clearly affect species; however, there is considerable variation among studies in whether this effect is evident, and thus a lack of clarity over the generality of the relationship. To understand how decreased food availability due to invertebrate declines will affect bird populations, we conducted a systematic review and used meta-analytic structural equation modelling, which allowed us to treat our core variables of interest as latent variables estimated by the diverse ways in which researchers measure fecundity and chick body condition. We found a moderate positive effect of food availability on chick body condition and a strong positive effect on reproductive success. We also found a negative relationship between chick body condition and reproductive success. Our results demonstrate that food is generally a limiting factor for breeding songbirds. Our analysis also provides evidence for a consistent trade-off between chick body condition and reproductive success, demonstrating the complexity of trophic dynamics important for these vital rates.