Northern Argentina Research Articles

Comparative genomic mapping reveals mechanisms of chromosome diversification in Rhipidomys species (Rodentia, Thomasomyini) and syntenic relationship between species of Sigmodontinae.

Rhipidomys (Sigmodontinae, Thomasomyini) has 25 recognized species, with a wide distribution ranging from eastern Panama to northern Argentina. Cytogenetic data has been described for 13 species with 12 of them having 2n = 44 with a high level of autosomal fundamental number (FN) variation, ranging from 46 to 80, assigned to pericentric inversions. The species are grouped in groups with low FN (46–52) and high FN (72–80). In this work the karyotypes of Rhipidomys emiliae (2n = 44, FN = 50) and Rhipidomys mastacalis (2n = 44, FN = 74), were studied by classical cytogenetics and by fluorescence in situ hybridization using telomeric and whole chromosome probes (chromosome painting) of Hylaeamys megacephalus (HME). Chromosome painting revealed homology between 36 segments of REM and 37 of RMA. We tested the hypothesis that pericentric inversions are the predominant chromosomal rearrangements responsible for karyotypic divergence between these species, as proposed in literature. Our results show that the genomic diversification between the karyotypes of the two species resulted from translocations, centromeric repositioning and pericentric inversions. The chromosomal evolution in Rhipidomys was associated with karyotypical orthoselection. The HME probes revealed that seven syntenic probably ancestral blocks for Sigmodontinae are present in Rhipidomys. An additional syntenic block described here is suggested as part of the subfamily ancestral karyotype. We also define five synapomorphies that can be used as chromosomal signatures for Rhipidomys.

Influence of extraordinary floods on wildlife parasites: the case of gastrointestinal helminths and protozoa of wild canids from the Iberá Ecoregion, Argentina.

Parasites are natural components of ecosystems and play a significant role in the dynamics of wild animal populations. Although the environment of parasites is primarily defined by the host, most life cycles involve stages that must endure external conditions. Rainfall and flooding events are important factors that might influence the transport of parasitic stages, altering soil moisture levels, and resulting in a favorable environment for parasite survival and development. We assessed whether an extraordinary flood event modified the occurrence of gastrointestinal parasites (nematodes and protozoa) in wild canids in two protected areas in northern Argentina. From 2016 to 2018, we collected fecal samples of two fox species, Lycalopex gymnocercus and Cerdocyon thous, and examined the presence of nematodes and protozoa. We assessed changes in the occurrence of these parasites after a flood event, while adjusting for potential confounders (i.e., monthly average temperature, season, host species, site). In a second stage of the analysis, we evaluated whether part of the effect was caused by changes in soil moisture, by adding normalized difference water index as an independent variable. We found that the presence of nematodes in foxes was higher after flooding than before flooding, and this association was not explained by changes in the soil moisture. On the other hand, the flood event was not relevant for protozoa. Stronger and long-lasting flood events are expected due to the effect of global warming on El Niño events, and this may increase and intensify the spread of some parasites affecting wildlife, which could also be of public health concern.

Leishmaniasis tegumentaria y flebótomos en la localidad de Colonia Santa Rosa del norte de Argentina

Tegumentary leishmaniasis (TL) is caused by parasites of the genus Leishmania and transmitted by the sandfly species, insects belonging to the order Diptera, family Psychodidae. Historically, the most endemic area of TL in Argentina has been the northern region. The aim of this work was to analyze the presence and temporal variation of TL cases reported between 1985 and 2019 in Colonia Santa Rosa locality, northern Argentina. Furthermore, its clinical forms were characterized and sandflies were captured. Patients were diagnosed by smear and the Montenegro skin test. For sampling, CDC light traps were placed at 14 sites from 7pm to 7am. The correlation between vegetation cover and sandfly abundance was also studied. One hundred and twenty TL cases were diagnosed and the overall prevalence was 0.75% (≈16 000 inhabitants). Patients presented simple and multiple cutaneous leishmaniasis (88.79%) and the mucocutaneous form (10.83%). Skin lesions were more frequent on the lower extremities (46.73%). Of the total number of sandflies, Nyssomyia neivai (95%) was the predominant species followed by Migonemyia migonei (1.9%), cortelezzii complex (1.3%) and Evandromyia sallesi (0.09%). The persistent occurrence of cases and the presence of sandflies in the locality suggest the existence of endemic transmission in the area. This highlights the need to design prevention and control measures for TL in northern Argentina.

Time-Activity Budget of the Snowy Sheathbill (Chionis albus) Wintering at a Sea Lion (Otaria flavescens) Haul-Out in Argentina

This work aims to provide information regarding the behavioral ecology of the least studied of the two sheathbill species, the Snowy Sheathbill (Chionis albus), wintering in northern Argentina in a male South American Sea Lion (Otaria flavescens) haul-out. Data about bird abundances and time allocated to behaviors was gathered during the final stage of three consecutive non-breeding seasons. Significant differences were found in the abundance between and within seasons. Overall, sheathbills allocated most of their time to foraging, followed by resting and self-maintaining, with the least of the time allocated to agonistic behaviors. The results obtained by the authors demonstrated that the Snowy Sheathbill recurrently used the local sea-lion haul-out as a foraging ground, with steady numbers throughout the non-breeding seasons.

The technical and the social: challenges in the conservation of earthen vernacular architecture in a changing world (Jujuy, Argentina)

Vernacular earthen architecture presents a series of relevant conservation challenges that involve designing solutions for different kinds of alterations and degradations. Other challenges of a social nature simultaneously arise and are related, among other factors, to the participation of local communities and the actions of different institutional actors. Understanding these phenomena has generally been approached from perspectives that take technical considerations and social dynamics as separate fields. The current global context has resulted in an acceleration of changes in these dynamics, in terms of both techniques and management models, giving rise to the need to develop comprehensive conceptual and methodological approaches through which these challenges should be addressed jointly by recombining the technical and the social.This paper will analyse the main problems affecting vernacular architectures in three communities in northern Argentina, where earthen techniques have been very relevant. We will reflect on various potentially useful theoretical frameworks, incorporating concepts from the anthropology of technology and methodological approaches from an ethnography of conservation as a way to work with multiple ontologies.

Wind trends analysis in southern South America from weather station and reanalysis data

AbstractSurface and upper‐level wind speed changes were analysed for several weather stations distributed throughout Argentina from 1990 to 2020. Both annual and seasonal wind speed trends were estimated for individual surface stations and available rawinsonde data. In order to explore the nature of these changes, different percentile time series were evaluated. NCEP/NCAR and ERA5 data were also assessed to verify how these long‐term changes are represented by the different reanalysis time series. A significant decline in measured surface wind speed is observed for most stations, with a reduction up to 13%·decade−1 in some of them. Despite differences on each station's wind speed distributions due to regional characteristics, the estimated trends were mostly negative for the annual 75th and 95th percentile time series. Upper‐level stations registered positive trends especially in the upper troposphere (200 hPa) in northern Argentina, while Patagonia's wind profile showed significant positive wind speed trends at most levels. Reanalysis data have severe limitations to reproduce the observed behaviour in the near‐surface levels, but managed to generate adequate estimates for the medium to high troposphere.

Global Land Surface Dry/Wet Conditions Mining Based on Spatial‐Temporal Association Rules

AbstractSevere drought and wetness would have serious impacts on human society and natural environment. Discovering the implicit relationships among severely dry/wet conditions is of great significance for meteorological disaster early warning and risk management strategy formulation. In this study, we propose an improved spatial‐temporal association rule mining algorithm to mine the global dry/wet associations. A modified time‐lagged association rule mining algorithm is first developed to mine unit‐to‐unit dry/wet association rules. Then, a density‐based clustering algorithm is employed to identify associated dry/wet zones. The gridded Standardized Precipitation Evapotranspiration Index (SPEI) data sets at 12‐ and 3‐month time scales were used to characterize annual and seasonal dry/wet conditions. Analysis results show that there are strong dry/wet associations between many regions. Some of the discovered association rules reflect similar associations with known phenomena, indicating the effectiveness and feasibility of the method. Other rules were previously unknown and can provide new knowledge for this research field. Several predictions can be made according to the discovered rules that western Oman and southeastern Saudi Arabia would suffer severe or extreme drought in 2021 and northwestern China would suffer severe or extreme drought in 2025 with probabilities exceeding 77%; northwestern China, northern Argentina, and western Australia would experience severe or extreme wetness in 2021, 2022, and 2023, respectively, with probabilities exceeding 85%. The algorithm provides a new perspective for analyzing dry/wet associations and the discovered associations can be used as theoretical bases for local governments to take precautions to mitigate the potential impacts of severe drought or wetness.

Angiostrongylus costaricensis

Angiostrongylus costaricensis is a parasitic nematode and the causative agent of abdominal angiostrongyliasis (AA) in humans. This nematode was described in Costa Rica 50 years ago and since then it has been reported from the southern USA to northern Argentina and the Caribbean. The parasites have rodent definitive hosts that shed L1 larvae in their feces, and terrestrial mollusks as intermediate hosts that bear L3 in the fibromuscular tissues of the foot. Humans are accidental hosts, where presence of the parasite in mesenteric arteries leads to vasculitis and an intense granulomatous inflammatory eosinophilic reaction surrounding eggs or larvae located in the intestinal mucosa, preventing the release of L1 in feces.

Incursion of tropically-distributed plant taxa into high latitudes during the middle Eocene warming event: Evidence from the Río Turbio Fm, Santa Cruz, Argentina

Plant species with predominantly tropical and subtropical modern distributions (or meso-megathermal species) penetrated into the highest southern latitudes of the American continent during the global warmest periods of the Cenozoic. These species – usually phylogenetically unrelated – became fossilized typically as dispersed spores and pollen grains. Here, we describe and illustrate fossil spores and pollen grains preserved during the Middle Eocene Climatic Optimum (MECO) in Patagonian southernmost latitudes (Río Turbio Formation). We study those species that today occurred in lower latitudes (e.g. northern Argentina and Brazil) and became locally extinct from Patagonia during the subsequent cooling episodes. We also estimate their frequency in the paleofloras. Our records show the presence of: Arecaceae, Cardiospermum (Sapindaceae), Cathedra (Olacaceae), Ceiba (Malvaceae, Bombacoideae), Cupania (Sapindaceae), Ilex (Aquifoliaceae), Malpighiaceae, Spathiphyllum (Araceae), Trimeniaceae, and tropical ferns, as Cnemidaria (Cyatheaceae) and Lygodium (Lygodiaceae). The angiosperm families are mostly pollinated by animals, especially insects. We found that these lineages occurred more frequently during MECO samples (~40 Mya) than in older (~44 Mya) and younger (~37 Mya) samples, suggesting that the southern dispersion of tropical elements occurred in waves, following this greenhouse episode. The study of fossil forms assigned to tropical families has previously been neglected in favor of Gondwanan canopy members such as southern beeches and podocarps. Our contribution sheds light into the most underrepresented members of the paleoflora and their key role in past plant–pollinator interactions.

Occurrence of Sturnira tildae De La Torre, 1959 (Chiroptera: Phyllostomidae) in the state of Maranhão, Brazil

The bat genus Sturnira is widely distributed in the Neotropical region, from northwestern Mexico to northern Argentina, and four species occur in Brazil: Sturnira lilium, Sturnira giannae, Sturnira magna, and Sturnira tildae. The present study is the first to record Sturnira tildae in the state of Maranhão, Brazil, based on morphological and molecular diagnoses. The specimen was identified based on its cranial and morphometric traits. The diagnostic traits include discreetly bilobed inner upper incisors with a broad base, lower first and second molars with lingual cusps separated by shallow grooves, and forearm longer than 45 mm. The molecular sequences of Cytochrome C Oxidase Subunit 1 (COI) and 16S rRNA genes confirmed the morphological identification and thus the occurrence of Sturnira tildae in the Amazon biome of Maranhão. This record represents an eastward extension of the known distribution of the species in the Amazonia, to Cândido Mendes, Maranhão, within an area dominated by dense rainforest and influenced by tides.

Projected impacts of 1.5 and 2°C global warming on temperature and precipitation patterns in South America

AbstractEven if the thresholds set out in the Paris Agreement are reached, several impacts on the climate system are still inevitable, generating new vulnerabilities and amplifying those that already exist. In this sense, the objective of this work was to analyse the impact of a global warming of 1.5 and 2°C in the regional climatological patterns of the near‐surface air temperature and precipitation over South America, locating the most affected regions and briefly discussing the possible impacts to be faced on biodiversity and agriculture. The simulations and projections of 26 General Circulation Models (GCMs) from the Coupled Model Intercomparison Project Phase 5 were used, forced in four different Representative Concentration Pathways (RCPs) scenarios. Projections for 1.5 or 2°C global warming indicate a local increase even higher, of at least +0.5°C, in almost the entire South American continent. Regarding precipitation, a similar pattern was also found between the two thresholds of global warming. GCMs project an increase of about 100 mm year−1 in the southern region of Brazil and in the northern portion of the Brazilian Northeast, in northern Argentina, Uruguay, and parts of Peru, Ecuador, Colombia and Venezuela; while the areas between the south of Chile and Argentina and the extreme north of South America show reductions of up to 150 mm year−1. In addition, both the temperature and precipitation patterns were practically similar between the four analysed RCPs scenarios. The results presented in this study indicate that even if the Paris Agreement is very successful, South America will still suffer several impacts and will need to take effective adaptation measures in the short term. This may have pervasive implications for the biodiversity and genetic resource base of the subcontinent, as well as may impair agricultural productivity or incur into considerable adaptation costs for the sector.

A reference genome for the nectar-robbing Black-throated Flowerpiercer (Diglossa brunneiventris).

Black-throated Flowerpiercers (Diglossa brunneiventris) are one species representing a phenotypically specialized group of tanagers (Thraupidae) that have hooked bills which allow them to feed by stealing nectar from the base of flowers. Members of the genus are widely distributed in montane regions from Mexico to northern Argentina, and previous studies of Diglossa have focused on their systematics, phylogenetics, and interesting natural history. Despite numerous studies of species within the genus, no genome assembly exists to represent these nectivorous tanagers. We described the assembly of a genome sequence representing a museum-vouchered, wild, female D. brunneiventris collected in Peru. By combining Pacific Biosciences Sequel long-read technology with 10× linked-read and reference-based scaffolding, we produced a 1.08 Gbp pseudochromosomal assembly including 600 scaffolds with a scaffold N50 of 67.3 Mbp, a scaffold L50 of 6, and a BUSCO completeness score of 95%. This new assembly improves representation of the diverse species that comprise the tanagers, improves on scaffold lengths and contiguity when compared to existing genomic resources for tanagers, and provides another avenue of research into the genetic basis of adaptations common to a nectivorous lifestyle among vertebrates.

Gross Discrepancies between Observed and Simulated Twentieth-to-Twenty-First-Century Precipitation Trends in Southeastern South America

AbstractSoutheastern South America (SESA; encompassing Paraguay, southern Brazil, Uruguay, and northern Argentina) experienced a 27% increase in austral summer precipitation from 1902 to 2019, one of the largest observed trends in seasonal precipitation globally. Previous research identifies Atlantic multidecadal variability and anthropogenic forcing from stratospheric ozone depletion and greenhouse gas emissions as key factors contributing to the positive precipitation trends in SESA. We analyze multimodel ensemble simulations from phases 5 and 6 of the Coupled Model Intercomparison Project (CMIP) and find that not only do Earth system models simulate positive SESA precipitation trends that are much weaker over the historical interval, but some models persistently simulate negative SESA precipitation trends under historical forcings. Similarly, 16-member ensembles from two atmospheric models forced with observed historical sea surface temperatures never simulate precipitation trends that even reach the lower bound of the observed trend’s range of uncertainty. Moreover, while future twenty-first-century projections from CMIP6 yield positive ensemble mean precipitation trends over SESA that grow with increasing greenhouse gas emissions, the mean forced response never exceeds the observed historical trend. Preindustrial control runs from CMIP6 indicate that some models do occasionally simulate centennial-scale trends in SESA that fall within the observational range, but most models do not. Results point to significant uncertainties in the attribution of anthropogenically forced influences on the observed increases in precipitation over SESA while also suggesting that internal decadal-to-centennial variability of unknown origin and not present in state-of-the-art models may have also played a large role in generating the twentieth-to-twenty-first-century SESA precipitation trend.

Eucalypt plantations for forest restoration in a fire‐prone mosaic of grasslands and forests in northern Argentina

In ecosystems with grassland‐forest boundaries, tree plantations could be used to promote forest restoration. In the Humid Chaco region of central South America, fire is one of the main disturbances that shapes the landscape. As eucalypt plantations are flammable, the contribution they can make to forest restoration is questionable. We planted saplings of five native tree species in three different environments (forests, grasslands, and eucalypt plantations) and assessed microclimatic conditions likely to influence sapling survival and growth. After 1 year, accidental fires that affected much of the study area allowed us to investigate the susceptibility of different environments to fire occurrence and post‐fire sapling survival. We planted 600 saplings in four plots per environment. We evaluated fire occurrence in the study area for 2 years and ask whether this factor affects sapling survival. In grasslands, microclimatic conditions were more extreme than in plantations. Plantations and forests showed high pre‐fire sapling survival but growth was almost double in plantations, similar to grasslands for most species. In the study area, fire frequency was similar in plantations and grasslands, whereas forests plots never burnt during the 2‐year study period. Fire reduced sapling survival in plantations, but not in grasslands where survival was low and similar in burned and unburned plots. For top‐killed plants, post‐fire resprouting ability was species‐specific. While more firm conclusions await future studies with even larger sample sizes, our results indicate that fire management may be necessary in order to use eucalypt plantations as nurses in this fire‐prone ecosystem.

Age, growth, maturity and extinction risk of an exploited and endangered skate, Atlantoraja castelnaui, from off Uruguay and northern Argentina.

The spotback skate Atlantoraja castelnaui (Arhynchobatidae) is a large and threatened skate species subjected to fishing pressure, endemic to the Southwest Atlantic that occurs from Rio de Janeiro, Brazil, to San Jorge Gulf, Argentina. The age, growth, age at maturity and the maximum intrinsic rate of population increase rmax of A. castelnaui were studied using 152 specimens collected from off Uruguay and north Argentina (35°-42° S), between June 2013 and February 2020. Vertebrae from 143 individuals were used for ageing (females: n= 83, size range 404-1300 mm total length, TL; males: n= 60, size range 400-1270 mm TL). Maximum ages determined for females and males were 30 and 28 years, respectively. To fit growth models, non-linear and Bayesian estimation approaches were considered. For the first approach, a set of four candidate growth (size-at-age) models were fitted: three-parameter von Bertalanffy, two-parameter von Bertalanffy with fixed L0 , Gompertz and Logistic. In the second approach, von Bertalanffy, Gompertz and Logistic were fitted. For non-linear estimation, model selection indicated that the entire set of candidate growth models were supported by the data. The von Bertalanffy was selected as the best model for Bayesian estimation. There were no differences in growth between sexes. For the sexes combined, the von Bertalanffy growth model by Bayesian method was considered the most adequate to describe the growth of A. castelnaui (growth mean parameters ± S.D.: L∞ = 1210.29 ± 40.68 mm; k=0.12 ± 0.01 years-1 ; L0 = 179.20 ± 11.62 mm). The age at maturity was estimated at 16.21 and 14.04 years for females and males, respectively. The maximum intrinsic rate of population increase rmax was estimated as 0.252 years-1 . Life-history traits and rmax provided in the present study suggest that this species has a relatively low productivity and may be vulnerable to an intense fishing pressure.

Umbrales del hedor: diálogos geoculturales entre la poesía de Teresa Orbegoso y la filosofía americanista de Rodolfo Kusch

The poetry of Peruvian writer Teresa Orbegoso interweaves Andean epistemologies and precarious materials in a land writing that is both geographical and cultural, and which is inspired in Rodolfo Kusch’ Americanist philosophy. Although the Kuschean philosophy, collected in his Obras completas, has received scarce attention within the field of ecocriticism, it has been described by Eduardo Gudynas (2010) as the precursor of ecophilosophical thought in Latin America. With a focus on Orbegoso's poetic approach, in this essay I intend to discuss how this contemporary poetry activates the Kuschean notion of "stench of the soil" inspired by the ancestral Aymara and Quechua knowledge of northern Argentina, southern Bolivia and the peoples of Peru with the objective to highlight a poetic-philosophical approach to the soil. In addition, I place Kusch’s Americanist philosophy within the frame of contemporary ecocritical discussions that update ancestral epistemologies as a source of knowledge for the present and the future. I also propose to recover a critical vocabulary from Rodolfo Kusch's philosophy in order to understand the elaborations of this contemporary poetry that approaches notions of the ground and the soil from the ancestral, the corporeal and the precarious through making use of a Latin American philosophical episteme.

The joint impacts of Atlantic and Pacific multidecadal variability on South American precipitation and temperature

AbstractSouth American climate is influenced by both Atlantic multidecadal variability (AMV) and Pacific multidecadal variability (PMV). But how they jointly affect South American precipitation and surface air temperature is not well understood. Here we analyze composite anomalies to quantify their combined impacts using observations and reanalysis data. During an AMV warm (cold) phase, PMV-induced JJA precipitation anomalies are more positive (negative) over 0°-10°S and southeastern South America, but more negative (positive) over the northern Amazon and central Brazil. PMV-induced precipitation anomalies in DJF are more positive (negative) over Northeast Brazil and southeastern South America during the warm (cold) AMV phase, but more negative (positive) over the central Amazon Basin and central-eastern Brazil. PMV’s impact on AMV-induced precipitation anomalies shows similar dipole patterns. The precipitation changes result from perturbations of the local Hadley and Walker Circulations. In JJA, PMV- and AMV-induced temperature anomalies are more positive (negative) over entire South America when the other basin is in a warm (cold) phase, but in DJF temperature anomalies are more positive (negative) only over the central Andes and central-eastern Brazil and more negative (positive) over southeastern South America and Patagonia. Over central Brazil in JJA and southern Bolivia and northern Argentina in DJF, the temperature and precipitation anomalies are negatively correlated. Our results show that the influence of Pacific and Atlantic multidecadal variability need to be considered jointly, as significant departures from the mean AMV or PMV fingerprint can occur during a cold or warm phase of the other basin’s mode.

Tremarctos ornatus(Carnivora: Ursidae)

AbstractTremarctos ornatus (F.G. Cuvier, 1825) is a tremarctine bear commonly known as the Andean bear. It is a medium-sized bear with black to dark red-brown pelage with dense, long, coarse fur; creamy white marks occur on the chin, neck, and chest, and often white to creamy marks occur on the face, around the muzzle, and eyes. It is distributed in the tropical Andes of Venezuela, Colombia, Ecuador, Perú, Bolivia, and northern Argentina in South America. T. ornatus is catalogued as “Vulnerable” (VU) by the International Union for Conservation of Nature and Natural Resources and is included in CITES Appendix I. Main threats include habitat loss and fragmentation, illegal killing, human–bear conflicts, and most likely climate change.

Molecular characterization of Giardia duodenalis and evidence for cross‐species transmission in Northern Argentina

Anthropogenic activities, such as human population expansion and land-use change, create ecological overlap between humans, domesticated animals, and wildlife and can exacerbate the zoonotic transmission of parasites. To improve our understanding of this dynamic, we employed multi-locus genotyping to conduct a cross-sectional study of the potential for zoonotic transmission of the protozoan parasite Giardia duodenalis among humans, household associated livestock and dogs, and black and gold howler monkeys (Alouatta caraya) in the Corrientes Province of Argentina. We found Giardia prevalence to be highest in howler monkeys (90.3% (47/52)), followed by humans (61.1% (22/36)), dogs (44.4% (16/36)), and cattle (41.9% (18/43)). We further established that howler monkeys exclusively harbored strains of assemblage B (100%) while humans were infected with either assemblage A (13.3%) or B (80%) or A and B (6.7%), and cattle and dogs were infected with either assemblage A (cattle, 94.1%; dogs, 80%)), A and C (10%), or their host-adapted assemblage (cattle, 5.9%; dogs, 10%). Our finding of G. duodenalis in both humans and domesticated animals (assemblage A) and humans and wild primates (assemblage B) suggests that cross-species transmission of multiple assemblages of G. duodenalis may occur in rural complexes such as northern Argentina where people, domesticated animals, and wildlife overlap. We further highlight the need to investigate the implications of these results for human health, the economics of livestock production, and wildlife conservation in this and similar systems.

First evidence of anthropogenic debris in nests of the Kelp Gull (Larus dominicanus) from a small semi-desert Argentinean coastal ecosystem

Here, we present the first findings of anthropogenic debris (AD) used as nest material by the Kelp Gull (Larus dominicanus) on a small semi-desert coastal ecosystem in northern Argentine Patagonia. Anthropogenic debris was found in ca. 40% of the 259 active nests, with an average of 2.80 ± 2.60 items per nest (n = 126) with >1 item recorded in >50% of surveyed nests containing debris. The average weight of AD per nest was 4.58 ± 12.74 g; the heaviest debris item weighed 82.58 g. Fragmented plastics were more abundant than unbroken items. Plastic followed by paper dominated the fraction of AD, with flexible plastic items dominating at both sites (nests: 97%, adjacent beach: 82%). Mega-sized plastics (>10 cm in length) and white/clear debris prevailed at both gull nests and the adjacent beach; fisheries and recreational activities were identified as the main sources of AD.